JP6935897B2 - Reaction film forming apparatus and forming method by magnetron sputtering method - Google Patents

Description

The present invention relates to a reaction membrane forming apparatus and a forming method by a magnetron sputtering method.

The inventor of the present invention has previously invented a film forming apparatus and a film forming method by a magnetron sputtering method using an arc discharge, so to speak, an arc discharge type magnetron sputtering method, which is proposed in Japanese Patent Application No. 2015-193124. According to this conventional technique, the object to be processed is housed inside the vacuum chamber. A magnetron cathode is provided in the vacuum chamber. The magnetron cathode has a target and a magnetic field generating means for generating a magnetic field in the vicinity of the surface to be sputtered of the target. The magnetron cathode is provided so that the surface to be sputtered of the target faces the surface to be processed of the object to be processed. A discharge gas used to generate plasma is introduced into this vacuum chamber. At the same time, the vacuum chamber serves as an anode and the magnetron cathode serves as a cathode, and sputtering power is supplied to both of them. Then, the particles of the discharge gas are discharged, and plasma is generated in the vacuum chamber. Here, since a magnetic field is generated in the vicinity of the surface to be sputtered of the target as described above, the electrons (secondary electrons) in the plasma undergo spiral motion (cycloid motion or trochoidal motion) under the action of this magnetic field. .. As a result, the density of plasma in the vicinity of the surface to be sputtered is improved. The discharge mode of this plasma is a high voltage and small current glow discharge. Then, the ions in the plasma collide with the surface to be sputtered of the target, so that the particles of the target are ejected from the surface to be sputtered. The sputtered particles that are knocked out fly toward the surface to be treated, adhere to the surface to be treated, and are deposited. As a result, a film containing sputtered particles as a component is formed on the surface to be treated of the object to be treated. Further, a filament is provided between the surface to be sputtered of the target and the surface to be processed of the object to be processed. The thermionic emission amount The filament is heated by being supplied with electric power to emit thermionic electrons. At the same time, the vacuum chamber serves as an anode and the filament serves as a cathode, and electric power for discharge is supplied to both of them. As a result, the thermions emitted from the filament are accelerated, the frequency of the accelerated thermions colliding with the particles of the discharge gas increases, and a low-voltage, high-current arc discharge is induced around the filament. NS.

That is, according to this conventional technique, in addition to the plasma generated by glow discharge, extremely high-density plasma generated by arc discharge is generated between the surface to be sputtered of the target and the surface to be processed of the object to be processed. Therefore, the sputtered particles ejected from the surface to be sputtered of the target pass through the extremely high-density plasma due to this arc discharge while flying toward the surface to be processed of the object to be processed. This activates the sputtered particles and further ionizes them so that they have at least higher energy than in the neutral state. Then, the sputtered particles having high energy adhere to and deposit on the surface to be treated, so that a highly hard and dense film is formed on the surface to be treated.

According to this conventional technique, a reaction membrane (compound membrane) can also be formed. In this case, the reactive gas that is the material of the reaction membrane, in other words, the reactive gas that has the property of reacting with the sputtered particles, is introduced into the vacuum chamber. The reactive gas is then decomposed and ionized by the plasma. Then, the particles of the ionized reactive gas and the ionized sputter particles react with each other, and a reaction film containing these particles as a component is formed on the surface to be treated. In the formation of such a reaction film, it is desirable that the vacuum chamber serves as an anode and the object to be treated serves as a cathode, and bias power is supplied to both of them. By supplying this bias power, the ionized sputter particles and the ionized reactive gas particles are accelerated toward the surface to be processed, and the reaction film formed on the surface to be processed is formed. Further increase in hardness is achieved.

By the way, in this conventional technique, when the surface to be sputtered of the target is observed, a reaction film is formed even in a non-erosion region where it is difficult to sputter, so to speak, an undesired film is formed. Then, this unwilling film grows as the film formation time becomes longer, similar to the so-called intentional reaction film formed on the surface to be treated of the object to be treated. However, when this unwilling film grows to a certain extent, it peels off from the non-erosion region in the form of a fine powder due to its own internal stress. Then, when the exfoliated fine powder falls into the erosion region and is sputtered, the particles scattered (splashed) by this sputtering, so to speak, the splash particles adhere to the surface to be treated, strictly speaking. It adheres to the surface of the reaction film formed on the surface to be treated. As a result, there is a disadvantage that the surface of the reaction membrane is roughened. Incidentally, when the film formation time is relatively short, in other words, when the film thickness of the reaction film to be formed is, for example, about 1 μm or less, such an inconvenience does not occur. On the other hand, when the film formation time is relatively long, for example, when the film thickness of the reaction film to be formed exceeds 3 μm, the inconvenience occurs.

That is, in the prior art, there is a problem that a reaction film having a smooth surface cannot be formed even if the film thickness is large. This problem is not limited to the arc discharge type magnetron sputtering method, but also occurs in a so-called general magnetron sputtering method using only glow discharge. When forming a film of a single metal, for example, instead of a reaction film, the above-mentioned unwilling film is not formed, that is, the problem does not occur.

Therefore, an object of the present invention is to provide an apparatus and a method for forming a reaction film by a magnetron sputtering method, which can form a reaction film having a large film thickness and a smooth surface. ..

In order to achieve this object, the present invention includes a first invention relating to a reaction membrane forming apparatus by a magnetron sputtering method and a second invention relating to a reaction membrane forming method by the magnetron sputtering method.

First, the first invention relates to an apparatus for forming a reaction film by a magnetron sputtering method as described above, and includes a vacuum chamber in which an object to be processed is housed. A magnetron cathode is provided in the vacuum chamber. The magnetron cathode has a target and a magnetic field generating means for generating a magnetic field in the vicinity of the surface to be sputtered of the target. The magnetron cathode is provided so that the surface to be sputtered of the target faces the surface to be processed of the object to be processed. Further, a gas introducing means for introducing the discharge gas used for generating plasma and the reactive gas used as the material of the reaction film formed on the surface to be processed of the object to be processed into the inside of the vacuum chamber is provided. Has been done. In addition, a sputtering power supply means for supplying sputtering power to both of the vacuum tank as an anode and the magnetron cathode as a cathode is provided. When this sputtering power is supplied, the particles of the discharge gas are discharged, and plasma is generated inside the vacuum chamber. In particular, since a magnetic field is generated near the surface to be sputtered of the target, the electrons in the plasma spirally move under the action of this magnetic field. As a result, the density of plasma in the vicinity of the surface to be sputtered is improved. The discharge mode of this plasma is glow discharge. Then, the ions in the plasma collide with the surface to be sputtered of the target, so that the particles of the target are ejected from the surface to be sputtered. The sputtered particles that are knocked out fly toward the surface to be processed of the object to be processed. At the same time, the particles of the reactive gas are decomposed by the plasma. The reactive particles, which are the particles of the decomposed reactive gas, react with the sputtered particles flying toward the surface to be treated of the object to be treated, and adhere to and deposit on the surface to be treated of the object to be treated. As a result, a reaction film containing sputtered particles and reactive particles as components is formed on the surface to be treated of the object to be treated. On top of that, the first invention further includes a shutter means and a shutter control means. Of these, the shutter means is provided between the surface to be sputtered of the target and the surface to be processed of the object to be processed. This shutter means can transition between an open state in which the surface to be sputtered of the target is exposed toward the surface to be processed of the object to be processed and a closed state in which the surface to be sputtered of the target is shielded from the surface to be processed of the object to be processed. Is. Then, the shutter control means controls the shutter means so that the shutter means alternately transitions between the open state and the closed state (when the reaction film is formed). In addition to this, the gas introducing means stops the introduction of the reactive gas into the inside of the vacuum chamber when the shutter means is in the closed state.

That is, according to the first invention, when the shutter means is opened, the surface to be sputtered of the target is exposed toward the surface to be processed, so to speak, and the shutter means is closed. The second state, in which the surface to be sputtered of the target is shielded from the surface to be processed by the object to be processed, is alternately repeated. Here, when the target is in the first state (the shutter means is open), the surface to be sputtered of the target is exposed toward the surface to be processed, so that the reaction film is exposed on the surface to be processed. Is formed. Further, when the target surface to be sputtered has a non-erosion region, a reaction film is formed in the non-erosion region as well, so to speak, an undesired film is formed. This unwilling film grows as the film formation time becomes longer, and eventually roughens the surface of the reaction film formed on the surface to be treated, so to speak, as in the above-mentioned prior art. It becomes a factor to do. On the other hand, when in the second state (the shutter means is closed), the surface to be sputtered of the target is shielded from the surface to be processed of the object to be processed. At the same time, the introduction of the reactive gas into the vacuum chamber is stopped. As a result, the film forming process for forming the reaction film is interrupted. However, since the introduction of the discharge gas into the vacuum chamber is continued and the supply of the sputtering power is also continued, the ions in the plasma continue to collide with the sputtered surface of the target, that is, the non-erosion region. The surface to be sputtered including the above is sputtered. As a result, the unwilling film formed in the non-erosion region is removed, that is, the surface to be sputtered including the non-erosion region is washed. At this time, since the surface to be sputtered of the target is shielded from the surface to be processed by the object to be processed by the shutter means, the particles of the unwilling film removed from the non-erosion region of the surface to be sputtered are to be processed. Strictly speaking, it does not adhere to the surface and, strictly speaking, adhere to the surface of the reaction membrane formed on the surface to be treated, so that the surface of the reaction membrane is not roughened. By alternately repeating these first and second states, roughening of the surface of the reaction film caused by the unwilling film formed in the non-erosion region is suppressed, and the film formation process for a long time is performed. This can be carried out, that is, the reaction membrane having a large film thickness can be formed. As a result, it is possible to form a reaction film having a large film thickness and a smooth surface.

Further, in the first invention, a filament and a power supply means for discharging are provided. The filament is provided at a position closer to the surface to be sputtered of the target than the shutter means between the surface to be sputtered of the target and the surface to be processed of the object to be processed. Then, this filament is heated by receiving the supply of thermionic emission electric power to emit thermionic electrons. On the other hand, the discharge power supply means uses a vacuum chamber as an anode and a filament as a cathode to supply power for discharge to both of them. This accelerates the thermions emitted from the filament, increasing the frequency with which the accelerated thermions collide with the particles of the discharge gas (and reactive gas), inducing an arc discharge around the filament. Will be done.

According to this configuration, in addition to the plasma generated by the glow discharge described above, an extremely high-density plasma generated by the arc discharge is generated between the surface to be sputtered of the target and the surface to be processed of the object to be processed. Therefore, in the above-mentioned first state, that is, when the film forming process is performed, the sputtered particles ejected from the surface to be sputtered of the target are in the process of flying toward the surface to be processed of the object to be processed. It passes through extremely high-density plasma generated by arc discharge. This activates the sputtered particles and further ionizes them so that they have at least higher energy than in the neutral state. At the same time, the particles of the reactive gas are also more efficiently decomposed and ionized. As a result, the hardness and densification of the reaction film formed on the surface to be treated of the object to be treated are achieved. Since the filament is provided at a position closer to the surface to be sputtered of the target than the shutter means, in order to remove the unwilling film formed in the non-erosion region even in the above-mentioned second state. Even when the process for cleaning the surface to be sputtered including the non-erosion region is performed, the action of extremely high-density plasma due to the arc discharge extends. That is, the process for cleaning the surface to be sputtered of the target is efficiently performed by the action of extremely high-density plasma due to the arc discharge.

Further, the present invention is suitable for a configuration in which a magnetron cathode having a fixed magnetic field in which the position of the magnetic field generating means is fixed is adopted.

That is, the unwilling film referred to here is formed in the non-erosion region of the surface to be sputtered of the target as described above. This non-erosion region basically occurs in a magnetic field fixed magnetron cathode in which the magnetic field generating means is fixed, that is, the position of the magnetic field generating means does not move. Therefore, the first invention is extremely suitable for a configuration in which a magnetic field fixed magnetron cathode is adopted.

Further, in the first invention, the ratio of the period in the second state to the period in the first state is 0.05 to 0.5.

Regarding this ratio, for example, if it is excessive, that is, if the period in the second state is excessively long, the process for cleaning the surface to be sputtered of the target will be performed more than necessary, and the productivity will be increased. Decreases. On the other hand, if this ratio is too small, that is, if the period in the second state is excessively short, the treatment for cleaning the surface to be sputtered of the target is not sufficiently performed, that is, the above-mentioned unwilling film is sufficient. May not be removed. From these facts, the ratio of the period in the second state to the period in the first state is 0.05 to 0.5, preferably 0.1 to 0.3, for example. The period itself in the first state is appropriately determined according to various conditions such as the sputter power and the type (material) of the target. Article 2 The same applies to the period itself when it is in the body.

Further, it is desirable that the sputtering power in the second state is larger than the sputtering power in the first state.

That is, the sputtering power in the first state is appropriately determined according to various conditions. On the other hand, the sputtering power in the second state is from the viewpoint of efficiently cleaning the surface to be sputtered of the target, shortening the period in the second state, and improving productivity. , It is desirable to be as large as possible. Therefore, it is desirable that the sputtering power in the second state is larger than the sputtering power in the first state.

Further, depending on the type of the reactive gas and the type of the target, the reactive gas may also be used as the discharge gas. Specifically, when in the first state, the introduction of the discharge gas into the vacuum chamber may be stopped, and more specifically, the introduction of the rare gas as the discharge gas may be stopped. That is, the gas introduction means may be configured to do so. In this case, when in the first state, the reactive gas also functions as a discharge gas, that is, is also used as the discharge gas. At the same time, the reactive gas also functions as a sputtering gas that sputters the surface to be sputtered of the target.

By using the reactive gas as the discharge gas in this way, the consumption of the discharge gas can be suppressed, and the cost for forming the reaction film can be reduced.

Next, the second invention relates to a method for forming a reaction film by a magnetron sputtering method as described above, and includes a gas introduction process and a sputtering power supply process. In the gas supply process, the discharge gas used to generate plasma and the surface to be treated are formed inside the vacuum chamber in which the object to be processed is accommodated and the magnetron cathode is provided. A reactive gas, which is a material for the reaction membrane, is introduced. Then, in the sputtering power supply process, the vacuum chamber serves as an anode and the magnetron cathode serves as a cathode, and the sputtering power is supplied to both of them. As a result, the discharge gas is discharged, and plasma is generated inside the vacuum chamber. Here, the magnetron cathode has a target and a magnetic field generating means for generating a magnetic field in the vicinity of the surface to be sputtered of the target. The electrons in the plasma spirally move under the action of the magnetic field generated near the surface to be sputtered of the target. As a result, the density of plasma in the vicinity of the surface to be sputtered of the target is improved. The discharge mode of this plasma is glow discharge. Then, the ions in the plasma collide with the surface to be sputtered of the target, so that the particles of the target are ejected from the surface to be sputtered. Further, the magnetron cathode is provided so that the surface to be sputtered of the target faces the surface to be processed of the object to be processed. Therefore, the sputtered particles ejected from the surface to be sputtered of the target fly toward the surface to be processed of the object to be processed. At the same time, the particles of the reactive gas are decomposed by the plasma. The reactive particles, which are the particles of the decomposed reactive gas, react with the sputtered particles flying toward the surface to be treated of the object to be treated, and adhere to and deposit on the surface to be treated of the object to be treated. As a result, a reaction film containing sputtered particles and reactive particles as components is formed on the surface to be treated of the object to be treated. On top of that, the second invention further includes a shutter control process. In this shutter control process, the shutter means provided between the surface to be sputtered of the target and the surface to be processed of the object to be processed is controlled. Specifically, the shutter means has an open state in which the surface to be sputtered of the target is exposed toward the surface to be processed of the object to be processed and a closed state in which the surface to be sputtered of the target is shielded from the surface to be processed of the object to be processed. And, it is possible to transition to. Then, in the shutter control process, the shutter means is controlled so that the shutter means alternately transitions between the open state and the closed state (when the reaction film is formed). In addition to this, when the shutter means is in the closed state, in the gas introduction process, the introduction of the reactive gas into the inside of the vacuum chamber is stopped, the introduction of the discharge gas is continued, and the upper sputtering power supply process is performed. Then, the supply of the sputter power will be continued. Further, in the second invention, the filament provided between the surface to be sputtered and the surface to be processed closer to the surface to be sputtered than the shutter means receives the supply of thermionic emission power. The thermionic emission process, which is heated in It includes a discharge power supply process that induces discharge.

That is, the second invention is an invention of a method corresponding to the first invention as a so-called invention of a product. Therefore, according to the second invention, the same operation as that of the first invention is exhibited.

As described above, according to the present invention, it is possible to form a reaction film having a large film thickness and a smooth surface. This greatly contributes to extending the life of molds, tools, sliding parts, etc. and reducing the aggression against opponents.

It is a schematic diagram which shows the schematic structure of the arc discharge type magnetron sputtering apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which looked at the inside of the magnetron sputtering apparatus from above. It is a schematic diagram which shows the schematic structure of the magnetron cathode in the same embodiment. It is a schematic diagram which shows the mutual positional relationship between a magnetron cathode and a filament in the same embodiment. It is a photograph which shows the state of the magnetron cathode at the time of reproducing the inconvenience in the prior art as a comparison object in the same embodiment. It is a schematic diagram which shows the control procedure by a controller in the same embodiment. It is a schematic diagram which shows the control procedure in the prior art. This is a list showing the properties of the reaction membrane in the same embodiment in comparison with those in the prior art. It is a figure which shows the observation image by the microscope of the reaction membrane in the same embodiment in comparison with what in the prior art. It is a schematic diagram which shows the procedure different from FIG.

An embodiment of the present invention will be described in detail below.

As shown in FIGS. 1 and 2, the arc discharge type magnetron sputtering apparatus 10 according to the present embodiment includes a hollow substantially rectangular parallelepiped vacuum chamber 12. The vacuum chamber 12 is installed with a portion corresponding to one surface of the rectangular parallelepiped as an upper surface, a portion corresponding to another surface facing the upper surface as a lower surface, and a portion corresponding to the other four surfaces as a side surface. Has been done. In the horizontal direction of the inside of the vacuum chamber 12, the length dimension of one side surface is, for example, about 1100 mm. The height dimension inside the vacuum chamber 12 is, for example, about 800 mm. The shape and dimensions of the vacuum chamber 12 are examples, and are appropriately determined according to various conditions such as the size and number of objects to be processed, which will be described later. Further, the vacuum chamber 12 itself is made of a metal having high corrosion resistance and heat resistance, for example, stainless steel such as SUS304, and its wall portion is connected to a ground potential as a reference potential.

An exhaust port 14 is provided at an appropriate position on the wall portion of the vacuum chamber 12, for example, at a position deviated from the center of the wall portion forming the lower surface (position on the left side in FIG. 1). A vacuum pump as an exhaust means (not shown) is coupled to the exhaust port 14 via an exhaust pipe (not shown) outside the vacuum tank 12. The vacuum pump also functions as a pressure control means for controlling the pressure P in the vacuum chamber 12. In addition, an automatic pressure control device (not shown) is provided in the middle of the exhaust pipe, and this automatic pressure control device also functions as a pressure control means.

Further, at an appropriate position inside the wall portion forming the side surface of the vacuum chamber 12 (appropriate position of the right side wall portion in FIGS. 1 and 2), the magnetron cathode is electrically insulated from the vacuum chamber 12. 16 are arranged. With reference to FIG. 3, the magnetron cathode 16 has a substantially rectangular flat plate-shaped target 162 and a magnet unit 164 provided on the back side, which is one main surface of the target 162. The magnet unit 164 has a permanent magnet 166 as a magnetic field generating means and a housing 168 for accommodating the permanent magnet 166. Further, the permanent magnet 166 has, for example, an N pole 166a as one magnetic pole having a substantially rectangular frame shape provided along the peripheral edge of the target 162 while being in close contact with the back surface of the target 162, and a target inside the N pole 166a. It has an S pole 166b as a substantially square bar-shaped other magnetic pole provided so as to extend along the longitudinal direction of the target 162 while being in close contact with the back surface of the 162. As the target 162, for example, a target made of titanium (Ti) having a high purity (specifically, a purity of 99.99% or more) is adopted. The dimensions of the target 162 are, for example, 457 mm in the longitudinal direction (length dimension), 127 mm in the lateral direction (width dimension), and 8 mm in the thickness direction (thickness dimension). Further, a substantially rectangular groove-shaped gap 166c is provided between the N pole 166a and the S pole 166b of the permanent magnet 166. Further, the housing 168 is provided with, for example, a water cooling mechanism as a cooling means (not shown) for cooling the entire magnetron cathode 16 including the housing 168.

The magnetron cathode 16 is arranged so that the surface to be sputtered, which is the other main surface (front surface) of the target 162, is directed toward the center of the vacuum chamber 12, and the longitudinal direction of the target 162 extends along the vertical direction. Has been done. The magnetron cathode 16 is covered with the earth shield 18 except for the surface to be sputtered of the target 162, in other words, the magnetron cathode 16 is covered with the earth shield 18 with the surface to be sputtered exposed. The earth shield 18 is made of a metal having high corrosion resistance and heat resistance, for example, a stainless steel such as SUS304. The earth shield 18 is electrically insulated from the magnetron cathode 16 and electrically connected to the vacuum chamber 12. Although not shown, the portion of the wall of the vacuum chamber 12 where the magnetron cathode 16 and the earth shield 18 are provided is used during maintenance of the magnetron cathode 16 and the earth shield 18 including replacement of the target 162. Considering workability, it is desirable that the door can be opened and closed like a sliding door or a hinged door.

Further, as shown in FIG. 1, the magnetron cathode 16 is connected to a sputtering power supply device 20 as a sputtering power supply means outside the vacuum chamber 12. Then, the magnetron cathode 16 is supplied with DC power having a negative potential based on the ground potential as the sputtering power Es from the sputtering power supply device 20. In other words, the vacuum chamber 12 is used as an anode and the magnetron cathode 16 is used as a cathode, and DC sputtering power Es is supplied to both of them. The sputter power supply device 20 that is a supply source of the sputter power Es has a constant power mode that operates so that the power value of the sputter power Es is constant, and a so-called sputter voltage that is a voltage component of the sputter power Es. Alternatively, it is also referred to as a target voltage.) A constant voltage mode that operates so that Vs is constant and a so-called sputtering current (also referred to as a target current) Is that is a current component of the sputtering power Es are operated so as to be constant. It has three operation modes, a constant current mode and a constant power mode, and is set to operate in the constant power mode here.

In addition, a filament 22 as a thermionic emission means is provided in front of the magnetron cathode 16, specifically, in front of the surface to be sputtered of the target 162. The filament 22 is, for example, a linear linear body having a diameter of about 1 mm, and a refractory metal such as tungsten (W) is used as the material thereof. Here, with reference to FIG. 4 as well, particularly with reference to FIG. 4 (a), the filament 22 is viewed from a direction opposite to the direction in which the magnetron cathode 16 is arranged in the horizontal direction. For example, when viewed from the center of the vacuum chamber 12, the center of the surface to be sputtered of the target 162 is along the vertical direction, that is, along the longitudinal direction of the target 162, in other words, the target 162 is sputtered. It is provided so as to extend parallel to the surface. Further, as shown in FIG. 4B in particular, the filament 22 has a predetermined distance D from the surface to be sputtered of the target 162. If this distance D is excessively small, for example, the filament 22 may come into contact with the surface to be sputtered of the target 162 or the earth shield 18, which is extremely inconvenient. On the other hand, if the distance D is excessively large, the action of the magnetic field by the magnet unit 164 (permanent magnet 166) around the filament 22 becomes weak, and it becomes difficult to induce an arc discharge described later. Therefore, the distance D is preferably 5 mm to 50 mm, for example, 25 mm. The length dimension of the filament 22 is equal to or greater than the length dimension of the target 162, and strictly speaking, is equal to or greater than the length dimension of the erosion region 162a described later of the target 162, for example, 500 mm. Is. In addition, although not shown, tension is applied to both ends of the filament 22 or one end thereof to apply an appropriate tension to the filament 22 in order to maintain the linear state of the filament 22. A tension applying mechanism is provided as a means.

With reference to FIG. 1 again, both ends of the filament 22 are connected to, for example, an alternating current cathode power supply device 24 as a thermionic emission power supply means outside the vacuum chamber 12. Then, the filament 22 is heated to 2000 ° C. or higher by receiving the cathode power Ec as the thermionic emission power from the cathode power supply device 24 to emit thermions. The cathode power supply device 24 is not limited to an AC one, but may be a DC one.

Further, the filament 22 is connected to a discharge power supply device 26 as a discharge power supply means outside the vacuum chamber 12. Then, the filament 22 receives a negative potential DC power with reference to the ground potential as the discharge power Ed from the discharge power supply device 26. In other words, the vacuum chamber 12 is used as an anode and the filament 22 is used as a cathode, and DC discharge power Ed is supplied to both of them. The discharge power supply device 26, which is the supply source of the discharge power Ed, has a constant power mode that operates so that the power value of the discharge power Ed is constant, and the same as the sputter power supply device 20 described above. A constant voltage mode that operates so that the discharge voltage Vd, which is a voltage component of the discharge power Ed, is constant, and a constant current that operates so that the discharge current Id, which is a current component of the discharge power Ed, is constant. It has three operation modes, a mode and. However, the discharge power supply device 26 is set to operate in the constant voltage mode.

Then, paying attention to the inside of the position where the filament 22 is provided in the vacuum chamber 12, a plurality of objects to be processed 100, 100, ... Are arranged in the vacuum chamber 12. Specifically, a central axis Xa extending along the vertical direction is set at substantially the center of the vacuum chamber 12 in the horizontal direction, and the objects to be processed 100, 100, ... Have the central axis Xa. They are arranged at equal intervals along the circumferential direction of the central circle. Each object to be processed 100 is an elongated cylindrical object such as a drill blade, and extends along the vertical direction, that is, extends along the central axis Xa of the vacuum chamber 12. It is held by a holder 28 as a holding means. Each holder 28 is coupled to the vicinity of the peripheral edge of the disk-shaped revolution table 32 via the gear mechanism 30. The center of the revolution table 32 is located on the central axis Xa of the vacuum chamber 12, and at the center of the revolution table 32, one end of the rotation shaft 34 extending along the central axis Xa of the vacuum tank 12 is located. It is fixed. The other end of the rotary shaft 34 is coupled to the shaft 36a of the motor 36 as a rotary drive means outside the vacuum chamber 12.

That is, when the motor 36 is driven and the shaft 36a of the motor 36 rotates in the direction indicated by the arrow 200 in FIG. 1, the revolution table 32 rotates in the same direction, that is, in the direction indicated by the arrow 200 in FIG. Rotate. Along with this, each object to be processed 100 rotates around the central axis Xa of the vacuum chamber 12, and revolves, so to speak. At the same time, due to the rotational driving force transmission action of each gear mechanism 30, each holder 28 rotates about the vertical axis Xb passing through itself in the direction indicated by the arrow 202, for example, in FIGS. 1 and 2, respectively. Then, as the holder 28 itself rotates, the object to be processed 100 held by the holder 28 also rotates in the same direction, so to speak, rotates on its axis. The diameter of the revolution path (PCD; Pitch Circle Diameter) of the object to be processed 100 is, for example, about 600 mm. The revolution speed of the object 100 to be processed (rotation speed of the revolution table 32) is, for example, 0.5 rpm to 1 rpm. On the other hand, the rotation speed of the object to be processed 100 (the rotation speed of the holder 28 itself about the vertical axis Xb) is, for example, 30 rpm to 60 rpm, that is, 60 times the revolution speed. In addition, in FIGS. 1 and 2, 12 objects to be processed 100, 100, ... (Holders 28, 28, ... And gear mechanisms 30, 30, ...) are provided, but this number is an example. , Other numbers may be used.

At the same time, each object to be processed 100 is subjected to a substrate from a substrate bias power supply device 38 as a bias power supply means outside the vacuum chamber 12 via a holder 28, a gear mechanism 30, a revolution table 32 and a rotating shaft 34. Bias power Eb is supplied. In this substrate bias power Eb, the value of the substrate bias voltage Vb, which is a voltage component thereof, is a high level value of a positive potential based on the ground potential, a low level value of a negative potential based on the ground potential, and the like. It is a so-called bipolar pulse power that alternately transitions to. The high level value of the substrate bias voltage Vb is constant, for example, + 37V with respect to the ground potential. On the other hand, the low level value of the substrate bias voltage Vb can be arbitrarily adjusted, and the average value (DC conversion value) of the substrate bias voltage Vb can be arbitrarily set by this low level value. Further, the frequency of the substrate bias power Eb can also be arbitrarily set within the range of, for example, 50 kHz to 250 kHz. The duty ratio of the substrate bias power Eb (the ratio of the period during which the value of the substrate bias voltage Vb becomes a high level value in one cycle of the substrate bias voltage Vb) can also be arbitrarily set. Here, the frequency of the substrate bias power Ed is set to, for example, 100 kHz, and the duty ratio is set to, for example, 30%.

Further, an appropriate position inside the wall portion forming the side surface of the vacuum chamber 12 and outside the revolution path of the objects to be processed 100, 100, ..., For example, sandwiching the central axis Xa of the vacuum chamber 12. A carbon heater 40, for example, as a temperature control means is provided at a position opposite to the position where the magnetron cathode 16 is provided (the position on the left side in FIGS. 1 and 2). The carbon heater 40 is connected to a heater heating power supply device (not shown) outside the vacuum chamber 12. Then, the carbon heater 40 receives power for heating the heater of direct current or alternating current from the power supply device for heating the heater to generate heat, and in particular, heats the objects to be processed 100, 100, ....

Further, as shown in FIG. 1, a gas introduction pipe 42 for introducing various gases such as a discharge gas into the vacuum chamber 12 is provided at an appropriate position in the vacuum chamber 12, preferably in the vicinity of the filament 22. It is provided. A plurality of individual, for example, three branch pipes 44, 46, and 48 are connected to the gas introduction pipe 42 outside the vacuum chamber 12. One of these three branch pipes 44, 46 and 48, for example, the branch pipe 44 is for introducing a rare gas as a discharge gas, for example, argon (Ar) gas, into the vacuum chamber 12. That is, it is coupled to the source of the argon gas (not shown). The branch pipe 44 for argon gas includes an opening / closing valve 44a as an opening / closing means for opening / closing the flow of the argon gas, a mass flow controller 44b as a flow rate control means for controlling the flow rate of the argon gas, and the like. Is provided. Then, one of the other branch pipes 46 and 48, for example, the branch pipe 46 is for _{introducing, for example, hydrogen (H 2} ) gas as a cleaning gas into the vacuum chamber 12, that is, the hydrogen (not shown). It is coupled to the gas source. The branch pipe 46 for hydrogen gas is also provided with an on-off valve 46a for opening and closing the flow of the hydrogen gas and a mass flow controller 46b for controlling the flow rate of the hydrogen gas. _{Further, the remaining branch pipe 48 is for introducing, for example, nitrogen (N 2} ) as a reactive gas into the vacuum chamber 12, that is, it is coupled to a source of the nitrogen gas (not shown). The branch pipe 48 for nitrogen gas is also provided with an on-off valve 48a for opening and closing the flow of the nitrogen gas and a mass flow controller 48b for controlling the flow rate of the nitrogen gas. The on-off valves 44a, 46a and 48a are manually operated, but the mass flow controllers 44b, 46b and 48b are controlled by the main controller 50 as a control means described later. These gas introduction pipes 42, the branch pipes 44, 46 and 48, the on-off valves 44a, 46a and 48a, and the mass flow controllers 44b, 46b and 48b (strictly speaking, including the main controller 50) introduce gas. Functions as a means.

In addition, between the magnetron cathode 16 and the revolution path of the object to be processed 100, in detail, the surface to be sputtered (strictly speaking, the outer surface of the earth shield 18) of the target 162 and the object to be processed 100 closest to the surface to be sputtered. A shutter 52 as a shutter means is provided at a position closer to the object to be processed 100 than the filament 22. The shutter 52 has a substantially rectangular flat plate shape, and both main surfaces thereof are in a state of being aligned with the surface to be sputtered of the target 162. Then, the shutter 52 moves (slides) in the horizontal direction as shown by an arrow 204 in FIG. 2 by a driving force of a motor as a shutter driving means (not shown). In other words, the shutter 52 is in an open state where the surface to be sputtered of the target 162 is exposed toward the space where the objects to be processed 100, 100, ... Are placed, and the surface to be sputtered of the target 162 is exposed to the objects to be processed 100, 100. It is possible to transition to a closed state that shields from the space where ，… is placed. The motor as the shutter driving means for driving the shutter 52 is also controlled by the main controller 50.

As described above, the main controller 50 controls the mass flow controllers 44b, 46b and 48b and the motor as the shutter driving means. The main controller 50 also controls the sputter power supply device 20, the cathode power supply device 24, and the discharge power supply device 26 described above. Further, the main controller 50 also controls the motor 36 as the rotation driving means. Such a main controller 50 is realized by, for example, a personal computer. The lines connecting the main controller 50 and each control target by the main controller 50 are not shown in consideration of the legibility of the drawings.

The arc discharge type magnetron sputtering apparatus 10 of the present embodiment configured in this way is the same as that in the above-mentioned prior art (proposed in Japanese Patent Application No. 2015-193124) in terms of hardware. However, the configuration of the main controller 50, specifically the software configuration, is different, and in particular, the control procedure of the mass flow controller 48b for nitrogen gas and the control procedure of the motor as the shutter driving means are different. Although the main controller 50 and the shutter 52 are not particularly mentioned in the prior art, they are actually provided in the same manner in the prior art. Further, in the prior art, the vacuum chamber has a substantially cylindrical shape, which is different from the substantially rectangular parallelepiped shape in the present embodiment, but the shape of this vacuum chamber depends on various conditions such as the number and size of the objects to be processed 100. It is appropriately determined accordingly and is not an element directly related to the main purpose of the present embodiment.

According to the arc discharge type magnetron sputtering apparatus 10 of the present embodiment, a titanium nitride (TiN) film as a reaction film can be formed on the surface of each object to be processed, that is, the surface to be processed. Strictly speaking, a titanium layer as an intermediate layer is formed prior to the formation of the titanium nitride film. On top of that, a titanium nitride film as a main layer is formed, so to speak. By providing the titanium layer as the intermediate layer in this way, the adhesion of the titanium nitride film to the surface to be treated of each object to be treated 100 can be improved.

Specifically, first, the objects to be processed 100, 100, ... Are installed in the vacuum chamber 12, that is, the objects to be processed 100, 100, ... Are installed in the holders 28, 28, ... Then, the inside of the vacuum chamber 12 is exhausted by the vacuum pump until the pressure P reaches ^{, for example, about 2 × 10 -3 Pa.} After this so-called evacuation or in parallel with this evacuation, the motor 36 is driven and the self-revolution of the objects to be processed 100, 100, ... Is started. Then, the carbon heater 40 heats the objects to be processed 100, 100, ... To, for example, about 150 ° C. As a result, the impurity gas contained in the objects to be treated 100, 100, ... Is discharged, and the so-called degassing treatment is performed. In this degassing treatment, the shutter 52 may be opened or closed.

After this degassing treatment is performed for a predetermined time (about 30 minutes to 1 hour), the heating by the carbon heater is stopped, and then the discharge cleaning treatment is performed. In this discharge cleaning process, the shutter 52 is opened. Then, the cathode power Ec is supplied to the filament 22. As a result, the filament 22 is heated to 2000 ° C. or higher, and thermions are emitted from the filament 22. At the same time, the electric power Ed for discharge is supplied to the filament 22. That is, the vacuum chamber 12 is used as an anode and the filament 22 is used as a cathode, and the discharge power Ed is supplied to both of them. As a result, the thermions emitted from the filament 22 as the cathode are directed toward the wall of the vacuum chamber 12 which is the anode, and are particularly close to the filament 22 and have the same potential as the vacuum chamber 12. Accelerate towards. In this state, argon gas is introduced into the vacuum chamber 12. Then, the accelerated thermions collide with the argon gas particles, and the impact causes the argon gas particles to be ionized to generate plasma 300. Here, since the magnetic field generated by the permanent magnet 166 described above is generated in the vicinity of the surface to be sputtered of the target 162 including the periphery of the filament 22, the thermions emitted from the filament 22 exert the action of this magnetic field. Receive and spiral. As a result, the frequency of thermions colliding with the argon gas particles increases, and the plasma 300 becomes denser. Such an aspect of the plasma 300 is an arc discharge with a low voltage and a large current. Further, hydrogen gas is introduced into the vacuum chamber 12. Then, the hydrogen gas particles are also ionized to form the plasma 300. The introduction of the argon gas into the vacuum chamber 12 and the introduction of the hydrogen gas into the vacuum chamber 12 may be started at the same time.

When the substrate bias power Eb is supplied to the objects to be processed 100, 100, ... In the state where the plasma 300 is generated by the arc discharge in this way, the argon ions and hydrogen ions in the plasma 300 are respectively processed. It is positively incident on the surface to be treated of the object 100, particularly the surface to be processed of the object 100 to be treated which is exposed to the plasma 300. As a result, the sputtering action caused by the argon ions colliding with the surface to be treated of each object 100 to be treated and the hydrogen ion chemically react with the impurities adhering to the surface to be treated of each object 100 to be treated. By the chemical reaction action, impurities are removed from the surface to be treated of each of the objects to be treated 100, that is, a discharge cleaning treatment is performed. The argon gas in this discharge cleaning process functions as a discharge gas for generating the plasma 300, and also functions as a cleaning gas for realizing the discharge cleaning process by a sputtering action as described above. On the other hand, the hydrogen gas functions as a cleaning gas that realizes a discharge cleaning process by a chemical reaction as described above, and also functions as a discharge gas.

In this discharge cleaning process, the flow rate of argon gas is set to, for example, 50 mL / min, and the flow rate of hydrogen gas is set to, for example, 150 mL / min. The pressure P in the vacuum chamber 12 is, for example, 0.2 Pa. Further, the discharge power Ed is set to, for example, 500 W. Specifically, the discharge power supply device 26, which is the supply source of the discharge power Ed, operates in the constant voltage mode as described above so that the discharge voltage Vd, which is a voltage component of the discharge power Ed, becomes 50 V. .. In this state, the heating temperature of the filament 22 is controlled by the cathode power Ec so that the discharge current Id, which is a current component of the discharge power Ed, becomes 10 A, that is, the amount of thermions emitted from the filament 22 is controlled. NS. As a result, the discharge power Ed is set to 500 W (= 50 V × 10 A). In addition, for the substrate bias power Eb, the average value of the substrate bias voltage Vb, which is a voltage component thereof, is −600 V. Incidentally, when the average value of the substrate bias voltage Vb is -600V, the low level value of the substrate bias voltage Vb is about -873V (= [-600V- {37V x 0.3}] /0.7). Is. Further, the substrate bias current Ib, which is a current component of the substrate bias power Eb at this time, is about 4A. This means that the relatively large substrate bias current Ib of about 4 A is flowing through the objects to be processed 100, 100, ... That is, so many ions are flowing to the objects 100, 100, .... It is shown that the light is incident on the surface to be treated, and that a larger discharge cleaning treatment effect (particularly, a bombardment effect due to the sputtering action of argon ions) can be obtained.

After this discharge cleaning process is performed for a predetermined time (about 30 minutes), a pre-sputtering process for cleaning the surface to be sputtered of the target 162 is performed. Therefore, the introduction of hydrogen gas into the vacuum chamber 12 is stopped. At the same time, the shutter 52 is closed. Then, the sputtering power Es is supplied to the magnetron cathode 16. That is, the vacuum chamber 12 is used as an anode and the magnetron cathode 16 is used as a cathode, and the sputtering power Es is supplied to both of them. Then, the argon ions in the plasma 300 are accelerated toward the magnetron cathode 16 which is the cathode, and particularly collide with the surface to be sputtered of the target 162, that is, sputter. By the sputtering action by the argon ion, dirt such as oxides and organic impurities adhering to the surface to be sputtered of the target 162 is removed, and the surface to be sputtered is cleaned. In this pre-sputtering process, the argon gas particles are also discharged by supplying the sputtering power Es, and a high voltage and small current glow discharge is induced. That is, the plasma 300 is in a state of including (mixing) the glow discharge in addition to the above-mentioned arc discharge. Then, the surface to be sputtered of the target 162 is efficiently cleaned by the action of the extremely high-density plasma 300 including the arc discharge. Further, as described above, since the magnetic field is generated in the vicinity of the sputtered surface of the target 162, the density of the plasma 300 in the vicinity of the sputtered surface of the target 162 becomes particularly high. As a result, the surface to be sputtered of the target 162 can be cleaned more efficiently.

The flow rate of argon gas in this pre-sputtering treatment is, for example, 150 mL / min. The pressure P in the vacuum chamber 12 is, for example, 0.5 Pa. Further, the discharge power Ed is set to, for example, 500 W (= 50 V × 10 A). In addition, the sputter power Es is set to, for example, 8 kW. The sputtering power supply device 20, which is a supply source of the sputtering power Es, operates in a constant power mode so that the sputtering power Es becomes constant as described above. Further, regarding the substrate bias power Eb, the average value of the substrate bias voltage Vb, which is a voltage component thereof, is set to −100 V. Incidentally, when the average value of the substrate bias voltage Vb is -100V, the low level value of the substrate bias voltage Vb is about -159V (= [-100V- {37V × 0.3}] /0.7). Is. In this pre-sputtering process, the shutter 52 is closed, so that the dirt removed from the surface to be sputtered of the target 162 adheres to the surface to be processed of the objects to be processed 100, 100, ... The surface to be processed of the processed objects 100, 100, ... Will not be soiled.

After this pre-sputtering treatment is performed for a predetermined time (about 3 to 5 minutes), a film forming treatment for forming a titanium layer as an intermediate layer is performed. Therefore, the shutter 52 is opened. Then, the argon ions in the plasma 300 collide with the surface to be sputtered of the target 162 after the pre-sputtering treatment, and the particles of the target 162 are ejected from the surface to be sputtered. Then, the sputtered particles that have been knocked out are directed toward the surface to be processed of the objects to be processed 100, 100, ..., Especially toward the surface to be processed of the object to be processed 100 that is exposed to the plasma 300. It flies and adheres to the surface to be treated. As a result, a titanium layer is formed on the surface to be treated of the objects to be treated 100, 100, .... Here, the sputtered particles ejected from the surface to be sputtered of the target 162 pass through the extremely high-density plasma 300 including an arc discharge while flying toward the surface to be processed of the objects to be processed 100, 100, ... pass. This activates the sputtered particles and further ionizes them so that they have at least higher energy than in the neutral state. Then, the hardness and densification of the titanium layer are achieved.

The flow rate of argon gas in the film forming process for forming the titanium layer is, for example, 150 mL / min. The pressure P in the vacuum chamber 12 is, for example, 0.5 Pa. Further, the discharge power Ed is set to, for example, 1000 W. Specifically, the filament 22 is heated by the cathode power Ec so that the discharge voltage Vd, which is a voltage component of the discharge power Ed, is 50 V, and the discharge current Id, which is a current component of the discharge power Ed, is 20 A. The temperature is controlled. As a result, the discharge power Ed is set to 1000 W (= 50 V × 20 A). In addition, the sputter power Es is set to, for example, 8 kW. As for the substrate bias power Eb, the average value of the substrate bias voltage Vb, which is a voltage component thereof, is set to −100 V. By performing the film forming process under such conditions for, for example, 5 minutes to 10 minutes, a titanium layer having a film thickness of 0.1 μm to 0.2 μm is formed.

After the treatment for forming the titanium layer is performed, the film forming treatment for forming the titanium nitride film is performed. Therefore, nitrogen gas is introduced into the vacuum chamber 12. Then, the particles of the nitrogen gas are decomposed by the plasma 300. Then, the decomposed nitrogen gas particles, particularly nitrogen ions, react with sputtered particles flying toward the surface to be treated, particularly titanium ions, of the object to be treated 100, 100, ..., And the object to be treated 100. , 100, ... Adheres to the surface to be treated, and particularly adheres to and deposits on the surface to be treated of the object 100 to be treated which is exposed to the plasma 300. As a result, a titanium nitride film as a reaction film of nitrogen and titanium is formed on the surface to be treated of the objects to be treated 100, 100, ....

In the film forming process for forming the titanium nitride film, the flow rate of argon gas is, for example, 150 mL / min. The flow rate of nitrogen gas is, for example, 40 mL / min. However, immediately after the start of introduction of this nitrogen gas, the flow rate of the nitrogen gas is not immediately set to the expected flow rate of 40 mL / min, but is stepwise or continuous over a predetermined time (several minutes). The flow rate is gradually increased to the desired flow rate of 40 mL / min. As a result, a so-called inclined layer is formed in the vicinity of the boundary between the titanium nitride film and the titanium layer, in which the composition ratio of nitrogen and titanium changes stepwise or continuously along the film thickness direction of the titanium nitride film. By forming such an inclined layer, the adhesion of the titanium nitride film can be further improved. Further, in the film forming process for forming the titanium nitride film, the pressure P in the vacuum chamber 12 is set to, for example, 0.5 Pa. Further, the discharge power Ed is set to, for example, 1000 W (= 50 V × 20 A). In addition, the sputter power Es is set to, for example, 8 kW. As for the substrate bias power Eb, the average value of the substrate bias voltage Vb, which is a voltage component thereof, is set to −100 V.

By the way, by performing the film forming process for forming the titanium nitride film, the surface to be sputtered of the target 162 is sputtered, and in particular, the portion of the plasma 300 having a high density is efficiently sputtered. As a result, an erosion region 162a, which is a sputter mark, appears on the surface to be sputtered of the target 162, and as shown in FIG. The erotic region 162a of the above appears.

Further, when the film forming process for forming the titanium nitride film is continued, the titanium nitride film is formed on the surface to be sputtered of the target 162, specifically in the non-erosion region other than the erosion region 162a. So to speak, an unwilling titanium nitride film is formed. A state in which this is remarkable is shown in FIG.

The unwilling film formed in the non-erosion region shown in FIG. 5 has a longer film formation time, similarly to the so-called intentional titanium nitride film formed on the surface to be treated of the objects to be treated 100, 100, ... Grow with you. However, when this unwilling film grows to a certain extent, it peels off from the non-erosion region in the form of a fine powder due to its own internal stress. Then, when the exfoliated fine powder falls into the erosion region 162a and is sputtered, the particles scattered by the sputtering, so to speak, the splash particles adhere to the surface to be treated of the objects to be treated 100, 100, ... Strictly speaking, it adheres to the surface of the intentional titanium nitride film formed on the surface to be treated. As a result, there is a disadvantage that the surface of the intentional titanium nitride film is roughened.

Therefore, in the middle of the film forming process for forming the titanium nitride film, for example, when the above-mentioned unwilling film is likely to be formed in the non-erosion region of the surface to be sputtered of the target 162, or the unwilling film is formed. Shortly after, that is, at least before the unintentional film is detached from the non-erosion region, the film formation process is interrupted. Then, during the period during which the film forming process is interrupted, in other words, instead of the film forming process, the surface to be sputtered of the target 162 including the non-erosion region is washed in order to remove the unwilling film referred to here. Processing is performed.

Specifically, first, the shutter 52 is closed. Then, the introduction of nitrogen gas into the vacuum chamber 12 is stopped. In short, a state similar to that in the above-mentioned pre-sputtering treatment is formed. As a result, as in the case of the pre-sputtering treatment, the surface to be sputtered of the target 162 is washed by the sputtering action of argon ions, and the unintentional film is particularly removed from the non-erosion region. Also in the process for cleaning the surface to be sputtered of the target 162, the action of the extremely high-density plasma 300 including the arc discharge is exerted, and the process is efficiently performed.

In the process for cleaning the surface to be sputtered of the target 162, the flow rate of the argon gas is set to, for example, 150 mL / min. The pressure P in the vacuum chamber 12 is, for example, 0.5 Pa. Further, the discharge power Ed is set to, for example, 500 W (= 50 V × 10 A). In addition, the sputter power Es is set to, for example, 8 kW. Further, regarding the substrate bias power Eb, the average value of the substrate bias voltage Vb, which is a voltage component thereof, is set to −100 V. Incidentally, in the process for cleaning the surface to be sputtered of the target 162, the shutter 52 is closed as in the pre-sputtering process, so that the particles of the unwilling film removed from the non-erosion region are removed. It adheres to the surface to be treated of the objects to be treated 100, 100, ..., Strictly speaking, it adheres to the surface of the titanium nitride film formed on the surface to be treated, and the surface of the titanium nitride film is roughened. There is no such thing.

Then, after the surface to be sputtered is sufficiently cleaned (considered) by the process for cleaning the surface to be sputtered of the target 162, a film forming process for forming a titanium nitride film is performed again. That is, nitrogen gas is introduced into the vacuum chamber 12 again. After that, the shutter 52 is opened again. Then, until the titanium nitride film having the desired film thickness is formed, the film forming process for forming the titanium nitride film and the process for cleaning the surface to be sputtered of the target 162 are alternately repeated. ..

When the titanium nitride film having the desired film thickness is formed (assumed to be), the introduction of argon gas and nitrogen gas into the vacuum chamber 12 is stopped. At the same time, the supply of the sputtering power Es to the magnetron cathode 16 is stopped, and the supply of the cathode power Ec and the discharge power Ed to the filament 22 is stopped. As a result, the plasma 300 disappears. Further, the supply of the substrate bias power Eb to the objects to be processed 100, 100, ... Is stopped. Then, a constant cooling period is set while the pressure in the vacuum chamber 12 is gradually returned to the vicinity of the atmospheric pressure. After that, the drive of the motor 36 is stopped, so that the rotation of the objects to be processed 100, 100, ... Is stopped. Then, the inside of the vacuum chamber 12 is opened to the outside, and the objects to be processed 100, 100, ... Are taken out from the inside of the vacuum chamber 12. This completes a series of processes including the process for forming the titanium nitride film.

The control procedure by the main controller 50 in this series of processing, in particular, the introduction / non-introduction of each of argon gas, hydrogen gas and nitrogen gas, the supply / non-supply of each of the discharge power Ed, the sputter power Es and the substrate bias power Eb, and the shutter 52. The control procedure for the open state / closed state of the above is illustrated as shown in FIG. The introduction / non-introduction of each of argon gas, hydrogen gas and nitrogen gas is controlled via the corresponding mass flow controllers 44b, 46b and 48b. The supply / non-supply of each of the discharge power Ed, the sputter power Es, and the substrate bias power Eb is controlled via the discharge power supply device 26, the sputter power supply device 20, and the substrate bias power supply device 38. Further, the control of the open state / closed state of the shutter 52 is performed via a motor as a shutter driving means.

As shown in FIG. 6, at the time point t0 after the above-mentioned degassing treatment is performed, argon gas is introduced into the vacuum chamber 12 and hydrogen gas is introduced into the vacuum chamber 12. At the same time, the electric power Ed for discharge is supplied to the filament 22. Although omitted in FIG. 6, the cathode power Ec is also supplied to the filament 22 together with the supply of the discharge power Ed. Further, the substrate bias power Eb is supplied to the objects to be processed 100, 100, .... Then, the shutter 52 is opened. As a result, the discharge cleaning process is performed.

Then, at the time point t1 after the discharge cleaning process is performed for a predetermined time, the introduction of hydrogen gas into the vacuum chamber 1 is stopped and the shutter 52 is closed. As a result, the discharge cleaning process is completed. Then, at the time point t2 after the discharge cleaning process is completed, the sputtering power Es is supplied to the magnetron cathode 16. As a result, the pre-sputtering process is performed.

Further, at the time point t3 after this pre-sputtering treatment is performed for a predetermined time, the shutter 52 is opened. As a result, a film forming process for forming the titanium layer as an intermediate layer is performed.

Then, at the time point t4 after the film forming process for forming the titanium layer as the intermediate layer is performed for a predetermined time, nitrogen gas is introduced into the vacuum chamber 12. As a result, a film forming process for forming the titanium nitride film is performed. At this point t4, the flow rate of nitrogen gas is not immediately set to the desired flow rate, but is gradually or continuously gradually increased over a predetermined time, and finally is set to the desired flow rate. NS. As a result, the above-mentioned inclined layer is formed.

Further, the shutter 52 is closed at the time point t5 during the film forming process for forming the titanium nitride film. Then, the introduction of nitrogen gas into the vacuum chamber 12 is stopped. As a result, a process for cleaning the surface to be sputtered of the target 162 is performed in order to remove the above-mentioned unwilling film. In FIG. 6, at this time t5, it seems that the shutter 52 is closed and at the same time the introduction of nitrogen gas into the vacuum chamber 12 is stopped, but in reality, the shutter 52 is After a short time (several seconds, for example, about 3 to 5 seconds) has passed since the vacuum chamber was completely closed, the introduction of nitrogen gas into the vacuum chamber 12 is stopped. This is because it takes some time (several seconds, for example, about 1 to 3 seconds) for the shutter 52 to completely transition from the open state to the closed state, whereas nitrogen gas is introduced into the vacuum chamber 12. This is because the transition from the state of being in the state to the state in which the nitrogen gas is not introduced is instantaneous. In other words, for example, if these controls are performed at the same time, the introduction of nitrogen gas into the vacuum chamber 12 will be stopped before the shutter 52 is completely closed, which is a slight amount of titanium. This is because layers will be formed. In order to avoid the formation of the titanium layer, after the shutter 52 is completely closed, the introduction of nitrogen gas into the vacuum chamber 12 is stopped, so to speak, a time lag is provided in these controls.

Nitrogen gas is introduced into the vacuum chamber 12 again at the time point t6 when the surface to be sputtered is sufficiently cleaned (considered) by the process for cleaning the surface to be sputtered of the target 162. Then, the shutter 52 is opened. As a result, a film forming process for forming the titanium nitride film is performed again. In FIG. 6, it seems that the shutter 52 is opened at the same time as the nitrogen gas is introduced into the vacuum chamber 12 at this time t6, but in reality, nitrogen is introduced into the vacuum chamber 12. The shutter 52 is opened after a short time (several seconds to a maximum of 1 minute, for example, 10 seconds) has elapsed since the gas was introduced. That is, a time lag having a relationship opposite to that at the time point t5 described above is provided. This is also to avoid the formation of a titanium layer in the middle of the titanium nitride film.

Then, at the time point t7 during the film forming process for forming the titanium nitride film, the shutter 52 is closed again. Then, the introduction of nitrogen gas into the vacuum chamber 12 is stopped. As a result, a process for cleaning the surface to be sputtered of the target 162 is performed again. At this time point t7 as well, a time lag is provided between the control that the shutter 52 is closed and the control that the introduction of nitrogen gas into the vacuum chamber 12 is stopped, as in the above time point t5. ..

Further, at the time t8 when the surface to be sputtered is sufficiently cleaned (considered) by the process for cleaning the surface to be sputtered of the target 162, nitrogen gas is introduced into the vacuum chamber 12 again. Then, the shutter 52 is opened. As a result, a film forming process for forming the titanium nitride film is performed again. At this time point t8, the same time lag as the above time point t6 is provided.

After that, until the titanium nitride film having the desired film thickness is formed, the film forming process for forming the titanium nitride film and the process for cleaning the surface to be sputtered of the target 162 are alternately repeated. Is done. Then, at the time point 10 when the titanium nitride having the desired film thickness is formed (considered), the introduction of the argon gas and the nitrogen gas into the vacuum chamber 12 is stopped. At the same time, the supply of the sputtering power Es to the magnetron cathode 16 is stopped, and the supply of the discharge power Ed to the filament 22 is stopped. At this time, the supply of the cathode power Ec to the filament 22 is also stopped. Further, the supply of the substrate bias power Eb to the objects to be processed 100, 100, ... Is stopped. Then, the process proceeds to the end of a series of processes.

As described above, in the present embodiment, the process for forming the titanium nitride film and the process for cleaning the surface to be sputtered of the target 162 are alternately repeated, but in order to form the titanium nitride film among them. The time Td (= t5-t4, t7-t6, ...) Itself for which the above-mentioned processing is performed varies depending on various conditions such as the sputtering power Es and the type of the target 162. In the present embodiment, the time Td is, for example, 60 minutes. On the other hand, the time Tc (= t6-t5, t8-t7, ...) Itself for which the process for cleaning the surface to be sputtered of the target 162 is performed also changes depending on various conditions. In the present embodiment, the time Tc is set to, for example, 10 minutes.

However, the ratio of time Tc to time Td (= Tc / Td) is preferably 0.05 to 0.5. That is, if this ratio is excessive, that is, if the time Tc is excessively long, the process for cleaning the surface to be sputtered of the target 162 is performed more than necessary, and the productivity is lowered. On the other hand, if this ratio is too small, that is, if the time Tc is excessively short, the treatment for cleaning the surface to be sputtered of the target 162 is not sufficiently performed, and the unwilling film formed on the surface to be sputtered is sufficient. May not be removed. From these facts, the ratio of time Tc to time Td is set to 0.05 to 0.5, more preferably 0.1 to 0.3, for example.

As described above, according to the present embodiment, the film forming process for forming the titanium nitride film and the process for cleaning the surface to be sputtered of the target 162 are alternately repeated to obtain the surface to be sputtered. Roughening of the surface of the titanium nitride film due to the unwilling film formed in the non-erosion region can be suppressed, and the film formation process of the titanium nitride film can be realized for a long time. As a result, it is possible to form a titanium nitride film having a large film thickness and a smooth surface.

On the other hand, for example, in the above-mentioned prior art, the control procedure for forming the titanium nitride film, particularly the introduction / non-introduction of each of argon gas, hydrogen gas and nitrogen gas, discharge power Ed, sputtering power Es and substrate bias. FIG. 7 shows a control procedure for the supply / non-supply of each electric power Eb and the open / closed state of the shutter 52.

That is, at the time point t0'to the time point t4'shown in FIG. 7, the same control as that at the time point t0 to the time point t4 shown in FIG. 6 is performed. Then, at the time point t4', after the film forming process for forming the titanium nitride film is started, this film forming process is performed at the time point when the titanium nitride film having the desired film thickness is formed (considered). It will continue until t10'. When the film formation time TD'is long, an unwilling film is formed in the non-erosion region of the surface to be sputtered of the target 162 as shown in FIG. Note that FIG. 5 shows a state when the film formation time TD'is 5 hours. Then, due to this unwilling film, the surface of the titanium nitride film is roughened. In short, in the prior art, it is not possible to form a titanium nitride film having a smooth surface even if the film thickness is large.

FIG. 8 shows a comparison of the properties of the titanium nitride film according to the present embodiment and the titanium nitride film according to the prior art. The properties of the titanium nitride film according to the present embodiment in FIG. 8 show that the film formation time TD (= 5) is 5 hours in total when the above-mentioned film formation process over the time Td of 60 minutes is repeated 5 times. It is the property of the titanium nitride film formed over × Td). The properties of the titanium nitride film according to the prior art are also the properties of the titanium nitride film formed over the film formation time TD'of 5 hours.

As shown in FIG. 8, the film thickness, the processing temperature, the internal stress, and the Knoop hardness are all approximately the same between the titanium nitride film according to the present embodiment and the titanium nitride film according to the prior art (both). The difference is about the error). However, regarding the surface roughness, both the center line average roughness Ra and the ten-point average height Rz are much smaller in the titanium nitride film according to the present embodiment than in the titanium nitride film according to the prior art. That is, the titanium nitride film according to the present embodiment is much smoother than the titanium nitride film according to the prior art. Further, regarding the color tone, the titanium nitride film according to the present embodiment has a larger L value, a value, and b value than the titanium nitride film according to the prior art. This means that the titanium nitride film according to the present embodiment has a brighter and more vivid color tone than the titanium nitride film according to the prior art.

Then, FIG. 9 shows a comparison of observation images of the titanium nitride film according to the present embodiment and the titanium nitride film according to the prior art with a microscope. As can be seen from FIG. 10, for example, in the titanium nitride film according to the prior art shown in (b), many large splash particles having a maximum diameter of about 60 μm can be seen, but the titanium nitride according to the present embodiment shown in (a). No such large splash particles are found on the membrane, only small particulate matter (also thought to be splash particles) is visible. From this, it can be seen that according to the present embodiment, a smooth titanium nitride film can be formed as compared with the prior art.

As described above, according to the present embodiment, it is possible to form a titanium nitride film having a large film thickness and a smooth surface. This greatly contributes to extending the life of molds, tools, sliding parts, etc. and reducing the aggression against opponents.

The present embodiment is a specific example of the present invention, and does not limit the scope of the present invention.

For example, during the process for cleaning the surface to be sputtered of the target 162, a larger sputtering power Es may be supplied as compared with the film formation process for forming the titanium nitride film. As a result, the process for cleaning the surface to be sputtered of the target 162 is efficiently performed, the processing time Tc can be shortened, and the productivity can be improved.

Further, as shown in FIG. 10, during the period (t4 to t5, t6 to t7, ...) Where the film forming process for forming the titanium nitride film is being performed, argon gas is introduced into the vacuum chamber 12. May be stopped. In this case, during the period, the nitrogen gas as the reactive gas also functions as the discharge gas. In other words, the nitrogen gas is also used as a discharge gas. At the same time, the nitrogen gas also functions as a sputtering gas that sputters the surface to be sputtered of the target 162. As a result, the consumption of argon gas is suppressed, and the cost for forming the titanium nitride film can be reduced.

As the magnetron cathode 16, a magnet (magnetic field) fixed type in which the permanent magnet 166 is fixed, that is, the position of the permanent magnet 166 does not move is adopted, but the present invention is not limited to this. For example, even if a so-called wide area erosion type magnet is adopted, in which the permanent magnet 166 moves along the back surface of the target 162 to sputter the surface to be sputtered of the target 166 over a wide area and thus reduce the non-erosion area. good. However, as described above, since the unwilling film is formed in the non-erosion region of the surface to be sputtered of the target 162, the magnetron fixed type magnetron cathode 16 in which the non-erosion region appears larger than the wide area erosion type is adopted. The present invention is particularly suitable for the configuration.

In addition, in the present embodiment, a titanium film as an intermediate layer is provided, but this titanium film may not be provided. However, as described above, when the titanium film is provided, the adhesion of the titanium nitride film as the main layer can be improved.

Further, in the present embodiment, the titanium nitride film is taken as an example as the reaction film, but the present invention can also be applied when forming a reaction film other than the titanium nitride film. For example, a nitride film such as a chromium nitride (CrN) film, an aluminum nitride (AlN) film, a titanium aluminum nitride (TiAlN) film, an aluminum chromium nitride (AlCrN) film, a carbide film such as a titanium carbide (TiC) film, and titanium carbonitride. This is also used when forming a carbon nitride film such as a (TiCN) film, a chromium nitride (CrCN) film, an oxide film such as silicon oxide (SiO ₂ ), or an oxynitride film such as an aluminum nitride (AlON) film. The invention can be applied. Needless to say, the types of the reactive gas and the target 162 change depending on the type of the reaction membrane to be formed. At the same time, various conditions such as the sputter power Es and the discharge power Ed are appropriately determined. In particular, when the target 162 is an insulator, AC power is adopted as the sputter power Es and the discharge power Ed. Then, regarding the time Td required for the film forming process for forming the reaction film, the time Tc required for the process for cleaning the surface to be sputtered of the target 162, and the mutual ratio of each of these time Td and Tc. Is also determined as appropriate.

Further, as the shutter 52, a substantially rectangular flat plate shape is adopted, but the shutter 52 is not limited to this. The shape and the like of the shutter 52 are appropriately determined according to the mode of the magnetron cathode 16 and the vacuum chamber 12.

The target 162 of the magnetron cathode 16 is not limited to a substantially rectangular flat plate shape, but may be, for example, a substantially disc shape, or in the extreme, a curved surface to be sputtered. good. Further, the shape of the filament 22 is appropriately determined according to the shape of the target 16 (surface to be sputtered).

In addition, the number of magnetron cathodes 16 is not limited to one, and a plurality of magnetron cathodes 16 may be provided. In this case, it is desirable that a plurality of the magnetron cathodes 16 are provided along the circumferential direction of the central axis Xa of the vacuum chamber 12. At the same time, it is desirable that the filament 22 is attached to each magnetron cathode 16. According to this configuration, the formation rate of the reaction membrane can be improved, and thus the productivity can be further improved.

Further, bipolar pulse power is adopted as the substrate bias power Eb, but the present invention is not limited to this. For example, when the objects to be processed 100, 100, ... Are conductive substances, DC electric power may be adopted. However, since abnormal discharge may occur due to gas or the like contained in the objects to be processed 100, 100, ..., It is desirable to adopt bipolar pulse power from the viewpoint of preventing such abnormal discharge. Further, pulse power or high frequency power other than this bipolar pulse power may be adopted.

Then, in the present embodiment, the case where the present invention is applied to the arc discharge type magnetron sputtering apparatus 10 has been described, but the present invention is not limited to this. That is, the present invention can also be applied to a general magnetron sputtering apparatus using only glow discharge. However, as described above, according to the arc discharge type magnetron sputtering apparatus 10, it is possible to form a highly hard and dense reaction film as compared with a general magnetron sputtering apparatus.

10 Arc discharge type magnetron sputtering device 12 Vacuum tank 16 Magnetron cathode 20 Spatter power supply device 22 Filament 24 Cathode power supply device 26 Discharge power supply device 38 Board bias power supply device 42 Gas introduction pipe 44, 46, 48 Branch pipe 44a, 46a, 48a Open / close valve 44b, 46b, 48b Mass flow controller 50 Main controller 52 Shutter 100 Object 162 Target 164 Magnet unit 300 Plasma

Claims (6)

A vacuum chamber in which the object to be processed is housed, and
It has a target and a magnetic field generating means for generating a magnetic field in the vicinity of the surface to be sputtered of the target, and is provided inside the vacuum chamber so that the surface to be sputtered faces the surface to be processed of the object to be processed. With a magnetron cathode
A gas introducing means for introducing a discharge gas used for generating plasma and a reactive gas used as a material for a reaction film formed on the surface to be treated into the inside of the vacuum chamber.
A sputter power supply means for discharging the discharge gas and generating the plasma inside the vacuum chamber by supplying sputter power to both of them with the vacuum chamber as an anode and the magnetron cathode as a cathode.
Equipped with
The above, which comprises as a component the sputtered particles ejected from the surface to be sputtered by the ions in the plasma colliding with the surface to be sputtered and the reactive particles which are particles of the reactive gas decomposed by the plasma. A reaction film is formed on the surface to be treated.
In the reaction film forming apparatus by the magnetron sputtering method,
An open state is provided between the surface to be sputtered and the surface to be treated so that the surface to be sputtered is exposed toward the surface to be sputtered, and a closed state is provided so as to shield the surface to be sputtered from the surface to be treated. Transitional shutter means and
A shutter control means that controls the shutter means so that the shutter means alternately transitions between the open state and the closed state.
Further equipped,
When the shutter means is in the closed state, the gas introducing means stops the introduction of the reactive gas into the inside of the vacuum chamber and continues the introduction of the discharging gas, and the sputtering power supply means , Continue to supply the above spatter power,
A filament between the surface to be sputtered and the surface to be processed that is provided at a position closer to the surface to be sputtered than the shutter means and is heated by receiving power for emitting thermions to emit thermions. When,
A discharge power supply means for accelerating thermions and inducing an arc discharge around the filament by supplying discharge power to both of them with the vacuum chamber as an anode and the filament as a cathode.
Further equipped,
Reaction membrane forming device. The magnetron cathode is of a fixed magnetic field type in which the magnetic field generating means is fixed.
The reaction membrane forming apparatus according to claim 1. The ratio of the period during which the shutter means is in the closed state to the period during which the shutter means is in the open state is 0.05 to 0.5.
The reaction membrane forming apparatus according to claim 1 or 2. The sputter power when the shutter means is in the closed state is larger than the sputter power when the shutter means is in the open state.
The reaction membrane forming apparatus according to any one of claims 1 to 3. The reaction film forming apparatus according to any one of claims 1 to 4, wherein when the shutter means is in the open state, the introduction of the discharge gas into the vacuum chamber is stopped. The object to be processed is accommodated and a magnetron cathode is provided. The magnetron cathode has a target and a magnetic field generating means for generating a magnetic field in the vicinity of the surface to be sputtered of the target. Inside the vacuum chamber provided so as to face the surface to be treated of the object to be processed, the discharge gas used to generate plasma and the material of the reaction film formed on the surface to be processed of the object to be processed. Gas introduction process to introduce the reactive gas
A sputtering power supply process in which the vacuum chamber is used as an anode and the magnetron cathode is used as a cathode to supply sputtering power to both of them to discharge the discharging gas and generate plasma inside the vacuum chamber.
Equipped with
The above-mentioned sputtered particles ejected from the sputtered surface by collision of ions in the plasma with the sputtered surface and reactive particles which are particles of the reactive gas decomposed by the plasma are contained as components. A reaction film is formed on the surface to be treated.
In the method for forming a reaction membrane by the magnetron sputtering method,
An open state is provided between the surface to be sputtered and the surface to be treated so that the surface to be sputtered is exposed toward the surface to be sputtered, and a closed state is provided so that the surface to be sputtered is shielded from the surface to be treated. A shutter control process that controls the shutter means so that the transitionable shutter means alternately transitions between the open state and the closed state.
Further equipped
When the shutter means is in the closed state, in the gas introduction process, the introduction of the reactive gas into the inside of the vacuum chamber is stopped, the introduction of the discharge gas is continued, and the sputtering power supply process is performed. Continues to supply the above spatter power,
A filament provided between the surface to be sputtered and the surface to be processed at a position closer to the surface to be sputtered than the shutter means is heated by being supplied with electric power for thermionic emission and emits thermoelectrons. Thermionic emission process and
The discharge power supply process of accelerating thermions and inducing an arc discharge around the filament by supplying discharge power to both of them with the vacuum chamber as an anode and the filament as a cathode.
A method for forming a reaction film.

Images