JP3879009B2 - Sputtering cathode - Google Patents

Description

[0001]
[Industrial application fields]
  The present invention relates to a sputtering cathode of a magnetron sputtering apparatus, and more particularly to a sputtering cathode capable of forming a uniform thin film having a uniform thickness on the surface of a substrate while effectively consuming the entire target surface.
[0002]
[Prior art]
  Various sputtering cathode structures have been proposed for conventional sputtering apparatuses. Among them, magnetron type sputtering cathodes are most used industrially. The reason is that the film formation speed is high. There are various types of conventional magnetron cathodes. These types are, for example, “Thin Film Process” (Academic Press Publishing, 1978, edited by JL Vossen and W. Kern), pages 75 to 173, or “Thin Film Handbook” (published in 1983). Pp. 186 to 189 of the Japan Society for the Promotion of Science Thin Film No. 131 Committee).
[0003]
  At present, among magnetron type sputtering cathodes, a planar magnetron cathode provided with a target having a planar shape is most useful industrially.
[0004]
  A sputtering apparatus including a target having a planar shape is mainly used for manufacturing semiconductors and electronic components. Particularly, among electronic components, in a liquid crystal display (LCD) panel, a sputtering apparatus having a rectangular magnetron type sputtering cathode is used for forming electrodes and wirings. In recent years, with an increase in the size of the LCD panel, there has been an increasing demand for depositing a thin film on a substrate having a large area even in a sputtering apparatus.
[0005]
  Generally, one or a plurality of planar rectangular magnet units are used for a planar magnetron cathode provided with a target having a planar rectangular shape. A rectangular magnet unit is composed of a bar-shaped magnet as a central magnetic pole and an outer peripheral magnetic pole surrounding it on a yoke made of a soft magnetic material. The polarities of the central magnetic pole and the outer peripheral magnetic pole are opposite to each other.
[0006]
  As a technique for forming a thin film on a large-area substrate, JP-A-6-192833 discloses a configuration using a plurality of rectangular magnet units.
[0007]
[Problems to be solved by the invention]
  Conventionally, a sputtering cathode having a planar shape using a plurality of rectangular magnet units has a non-uniform ion bombardment on the target surface and a non-uniform plasma spatial density distribution when a thin film is formed on a large-area substrate. The problem of non-uniformity in film thickness distribution due to this has been raised.
[0008]
  This problem will be described with reference to the structure described in JP-A-6-192833. In this configuration, a flat plate sputtering cathode in which a plurality of rectangular magnet units are arranged is incorporated in a sputtering apparatus for a large area substrate.
[0009]
  When a negative voltage is applied between the magnetron cathode and the vacuum vessel wall to discharge in vacuum and the film is formed by sputtering, a closed tunnel-like shape is created on the surface of the flat plate target of the rectangular magnetron cathode. Electrons drift along the path and draw a loop-like trajectory. When there are a plurality of magnets, a plurality of loop-like trajectories are also generated. Since the drift electrons collide with the gas molecules and ionize them, a high-density plasma is formed along the locus drawn by the drift electrons. The target surface just below the locus drawn by the drift electrons is subjected to strong ion bombardment and sputtered. Actually, since there are a large number of drift electrons, the trajectory has a band shape having a certain width. Therefore, the plasma formed along this band also has a band shape. The region to be sputtered on the target surface also becomes a band-shaped loop region.
[0010]
  However, the strip-shaped plasma is not a plasma having a uniform density over the entire circumference, and the plasma density tends to be extremely high at locations corresponding to both ends in the longitudinal direction of the rectangular magnet unit. Furthermore, when a plurality of magnet units are used, a plurality of strip-shaped plasmas having a non-uniform density distribution are also generated. FIGS. 11A and 11B show the results of forming a thin film on the substrate using the plasma having this non-uniform density distribution. This figure is normalized by the value of the thickest film thickness in the substrate, and the film thickness distribution is shown by contour lines. Moreover, the numerical value in a figure is a percentage of the normalized film thickness. As shown in FIG. 11A, island-like thick regions (regions surrounded by 95% lines) appear in the diagonal direction on the lower left and upper right of the substrate. This state is referred to as “twisted”. This “twist” is turned to the lower left and upper right diagonals as shown in FIG. 11B by switching the polarities of the center magnetic pole and the outer magnetic pole of the magnet. Further, when the number of magnets is increased from one to a plurality, “twist” tends to be emphasized. The cause of “twist” has not been elucidated.
[0011]
  As a next problem, when a plurality of the same magnet units are arranged, there is a problem that the thickness of the obtained thin film becomes thin at a portion corresponding to the outermost magnet unit. This can be explained as follows. Where the same magnet units are adjacent to each other, they repel each other because of the magnets having the same polarity, and the magnetic field strength on the target surface is increased and the density of the generated plasma is increased. In the case of the outermost magnet unit, there is no magnet unit having the same polarity that repels both outer sides, so the magnetic field strength does not increase. Therefore, since the density of the plasma generated there is thin, the film thickness of the portion corresponding to the outermost magnet unit is thin.
[0012]
  Also, using the configuration described in Japanese Patent Application Laid-Open No. 6-192833, for example, when a plurality of magnet units are used and a thin film is formed by applying 5 kW of power, a thin film is prepared by applying 15 kW of power. The following problems occur when comparing the cases of performing the above.
[0013]
  (1) The uniformity of the film thickness distribution created with an input power of 15 kw is worse than the uniformity when created with an input power of 5 kw.
[0014]
  (2) The shape of the film thickness distribution of the thin film prepared at an input power of 15 kw tends to be recessed in the center of the substrate as compared to the film thickness distribution of the thin film generated at an input power of 5 kw.
[0015]
  These problems are caused by the fact that when the input electric power is increased, the electric power is concentrated in a portion corresponding to the “twist” of the strip-shaped plasma having a non-uniform density distribution. For this reason, the thick part of the thin film formed with the input power of 5 kw becomes thicker as the input power increases, and the film thickness distribution of the thin film depends on the input power at the time of film formation. It becomes. As another problem, (3) erosion of the target progresses due to continuous use of the sputtering cathode, and the film thickness distribution changes over time as the distance between the target surface and the magnet surface (hereinafter referred to as T / M) becomes shorter. Is produced.
[0016]
  When the target erosion progresses and the T / M distance is shortened, the magnetic field intensity on the target surface is increased and the plasma density of the strip-shaped plasma is increased. Furthermore, since the plasma density of the portion corresponding to the “twist” of the strip-shaped plasma is high, the erosion rate on the target surface is faster than the other portions. Therefore, since the distribution occurs in the T / M distance, the magnetic field strength distribution is generated on the target surface, and the plasma density of the strip plasma further increases, so that the film thickness distribution changes with time. .
[0017]
  Further, in the configuration described in JP-A-6-192833, when the entire magnet unit is reciprocated, for example, the film thickness distribution of the thin film obtained is worse than that obtained by stopping the magnet unit. There is a problem of doing. This is because when the plasma from the outermost magnet unit of the reciprocating magnet unit approaches the target shield arranged around the target, electrons in the plasma flow into the target shield and the plasma density becomes thin. is there. As a result, the film thickness distribution of the obtained thin film changes.
[0018]
  The rectangular parallel plate magnetron cathode using the rectangular magnet unit has various problems as described above.
[0019]
  An object of the present invention is to provide a sputtering cathode capable of solving the problem of non-uniform impact of ions on a target and forming a thin film having a uniform thickness distribution on a relatively large rectangular substrate. .
[0020]
[Means for Solving the Problems]
  The present invention includes a sputtering cathode in which at least one planar rectangular magnet unit is provided on the rectangular planar target and the back surface thereof, or a plurality of planar rectangular magnet units on the rectangular planar target and the back surface thereof. The sputtering cathode has the following characteristics.
[0021]
  Of this applicationIn the description and drawings,(1) In a sputtering cathode having a planar rectangular target and a plurality of planar rectangular magnet units on its back surface, the distance between the target surface and the magnet unit is changed at both ends in the long side direction of each magnet unit. A mechanism for adjusting the inclination angle of the surface of an arbitrary magnet unit with respect to the target surface and allowing the arbitrary magnet unit to move in a direction perpendicular to the target surfaceIs also described.
  No. of this applicationone(2) In a sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof, each magnet unit has a mechanism for reciprocating the magnet unit in parallel with the target surface. Use the installed configuration.
[0022]
  No. of this applicationtwo(3) In a sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof, a mechanism for tilting the surface of the magnet unit with respect to the target surface, and the magnet unit as a target A structure in which a mechanism for reciprocating parallel to the surface is attached to each magnet unit,Corresponds to the third invention of the present application,(4) In a sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof, a mechanism for tilting the surface of the magnet unit with respect to the target surface and moving the magnet unit in a direction perpendicular to the target surface A structure in which a mechanism and a mechanism for reciprocating a magnet unit in parallel with a target surface are attached to each magnet unit,Corresponds to the fourth invention of the present application,(5) In a sputtering cathode having a plurality of planar rectangular magnet units on the target and the back surface thereof, there is a mechanism for changing the distance between the target surface and the magnet unit at both ends in the long side direction of each magnet unit. A configuration in which each magnet unit is provided with a mechanism for reciprocating the magnet unit in parallel with the target surface.
[0023]
  In the specification and drawings of this application,(6) In the configuration of (1) or (5), a mechanism for changing the distance between the target surface and the magnet unit provided at both ends in the long side direction of each magnet unit is applied to the sputtering cathode. (7) In the configuration of any one of (1), (3), and (4), the surface of the magnet unit provided in each magnet unit is a target. A configuration in which a mechanism that controls the tilting mechanism with respect to the surface according to the power applied to the sputtering cathode is provided. (8) Each magnet provided in each magnet unit in the configuration of (1) or (4). A configuration in which a mechanism for moving the unit in a direction perpendicular to the target surface is controlled according to the power applied to the sputtering cathode, (9) (2), (3 , (4), (5) in the construction of the mechanism for reciprocating in parallel each magnet unit to the target surface, a mechanism for controlling in response to the power applied to the sputtering cathode arrangementIs also listed. With the above configuration, even when the film thickness distribution changes due to the change in the film thickness distribution due to the magnitude of input power during film formation, the amount of change can be minimized.
[0024]
  In the specification and drawings of this application,(10) In the configuration of (1) or (5), a mechanism for changing the distance between the target surface and the magnet unit provided at both ends in the long side direction of each magnet unit is provided at least in the vacuum chamber. In a configuration provided with a mechanism for controlling according to an instruction value of a film thickness measuring instrument installed in one place, (11) In any of the configurations of (1), (3), and (4), each magnet unit A structure provided with a mechanism for controlling a mechanism for inclining the surface of the magnet unit provided with respect to the target surface in accordance with an instruction value of a film thickness measuring device installed in at least one place in the vacuum chamber; (12) In the configuration of (1) or (4), a film thickness measuring instrument in which a mechanism for moving each magnet unit provided in each magnet unit in a direction perpendicular to the target surface is installed in at least one place in the vacuum chamber. Finger (13) In any one of the configurations (2), (3), (4), and (5), each magnet unit is reciprocated in parallel with the target surface. Configuration in which a mechanism is provided for controlling the mechanism in accordance with an instruction value of a film thickness measuring instrument installed in at least one place in the vacuum chamberIs also listed.
[0025]
  In the specification and drawings of this application,(14) In the configuration of (1) or (5), a mechanism for changing the distance between the target surface and the magnet unit provided at both ends in the long side direction of each magnet unit is a target of the magnet unit. (15) The structure provided with the mechanism controlled according to the relative position in the surface parallel to the surface, (15) In any one of the structures (1), (3), and (4), each magnet unit is provided. (16) The configuration (1) or (4), wherein a mechanism for controlling the mechanism for tilting the surface of the magnet unit with respect to the target surface according to the relative position in a plane parallel to the target surface of the magnet unit is provided. In this configuration, a mechanism for moving each magnet unit provided in each magnet unit in a direction perpendicular to the target surface is set according to the relative position of the magnet unit in a plane parallel to the target surface. (17) In the configuration of any one of (2), (3), (4), and (5), a mechanism for reciprocating each magnet unit in parallel with the target surface is provided as a magnet. Configuration to provide a control mechanism according to the relative position of the unit parallel to the target surfaceIs also listed.
[0026]
[Action]
  As described above, in the specification and drawings of the present application,In a sputtering cathode having a planar rectangular target and a plurality of planar rectangular magnet units on the back surface thereof, for changing the distance between the target surface and the magnet unit at both ends in the long side direction of each magnet unit A mechanism is provided to make it possible to adjust the inclination angle of the surface of an arbitrary magnet unit with respect to the target surface, and to move the arbitrary magnet unit in the direction perpendicular to the target surface ((Hereinafter referred to as “configuration (1)”). That is, both ends of the planar rectangular magnet unit in the long side direction can independently change the distance between the target surface and the magnet unit surface. There are two methods for changing the T / M distance at both ends of the magnet unit, and the T / M distance at both ends of the magnet unit is the same. Different T / M distances at both ends of the magnet unit correspond to tilting the surface of the magnet unit with respect to the surface of the target. Further, the case where the T / M distances at both ends of the magnet unit are equal corresponds to moving the magnet unit in the target normal direction while keeping the magnet unit surface parallel to the target surface. The effect | action by each change method is demonstrated.
[0027]
  (1) When the T / M distances at both ends of the magnet unit are different As described in the problem to be solved by the invention, when a plurality of magnet units are used, “twist” appears in the film thickness distribution, and the thin film film This is a cause of worsening the uniformity of the thickness distribution. To cancel the “twist” in the film thickness distribution, move the magnet unit corresponding to the thick part of the thin film away from the target surface, and tilt the magnet unit by moving the magnet unit closer to the target surface in the thin part of the thin film. Let When the magnet unit is arranged with an inclination, the magnetic field intensity on the target surface is weakened at a portion where the magnet unit surface is far from the target surface, and is strengthened at a portion approaching the target surface. For this reason, the strip-shaped plasma density produced | generated on the target surface becomes thin in the part which kept the magnet unit away, and becomes deep in the part which approached. The film thickness of the thin film at this time is thin at the part where the magnet unit is moved away and thick at the part where the magnet unit is moved away, so that the “twist” of the film thickness distribution can be canceled. By making this an appropriate inclination for each magnet unit, the uniformity of the film thickness distribution can be improved.
[0028]
  (2) When the T / M distances at both ends of the magnet unit are equal When a plurality of the same magnet units are arranged, the film thickness of the obtained thin film may be thin at the portion corresponding to the outermost magnet unit. In order to prevent this, the plasma density corresponding to the outermost magnet unit may be made higher than the plasma density of other magnet units. For this reason, in order to make the magnetic field strength of the outermost magnet unit stronger than other magnet units, the magnet unit is brought closer to the target surface. By adopting such an arrangement method, the uniformity of the film thickness distribution of the thin film is improved. Furthermore, when the target surface erodes and the target thickness decreases, the T / M distance becomes closer and the magnetic field strength on the target surface becomes stronger, so that the film thickness distribution changes with time. In order to prevent this, film thickness distribution is achieved by moving the magnet unit vertically in the direction of the target surface along with the depth of erosion on the target surface, and keeping the T / M distance constant at all times. Can be prevented over time.
[0029]
  According to the configuration of (1), in a sputtering cathode having a planar rectangular target and a plurality of planar rectangular magnet units on the back surface thereof, the long side direction of each magnet unit is A mechanism for changing the distance between the target surface and the magnet unit is provided at both ends, the tilt angle of the surface of the arbitrary magnet unit with respect to the target surface can be adjusted, and the arbitrary magnet unit can be made perpendicular to the target surface. By making it possible to move in the direction, the optimum arrangement in each magnet unit can be easily adjusted, and a thin film with good uniformity can be obtained.
  In the configuration described in the specification and drawings of the present application,In a sputtering cathode having a plurality of magnet units, the mounting interval of each magnet unit is adjusted. The sputtered particles mainly jump out of the band-shaped region (erosion) sputtered by the band-shaped plasma on the target surface. When the attachment interval of each magnet unit is increased, the interval between each erosion also increases with the magnet unit, so that a thin film can be formed in a wide area, but the film thickness corresponding to the intermediate portion of each magnet unit is reduced. In the present invention, since the mounting interval of each magnet unit can be changed independently, an appropriate erosion interval can be set such that the difference between the erosion film thickness and the erosion film thickness difference is reduced. It is possible to obtain a wide region with a uniform thin film thickness distribution on a large-area substrate. In addition, since all the magnet units are synchronized with their mounting intervals maintained, and a mechanism that can reciprocate in parallel with the target surface is provided, the proper erosion distribution for obtaining a uniform film thickness over a wide area The entire surface of the target can be eroded by reciprocating the entire erosion while maintaining. For this reason, there exists an effect of the reduction of a particle, and the improvement of a target utilization factor.
[0030]
  In the configuration described in the specification and drawings of the present application,A thin film with good uniformity of film thickness distribution can be obtained by combining the mounting arrangement of the magnet units.That is,The arrangement of the magnet units is adjusted so as to widen the region where the film thickness distribution of the thin film has good uniformity, cancel the “twist”, and form a thin film with good film thickness distribution uniformity. Each action is as described above.
[0031]
  In the configuration described in the specification and drawings of the present application,A mechanism for monitoring the power applied to the sputtering cathode;Combining the magnet unit mounting arrangement described abovecombinationing. As described above, when the thin film is formed, there are problems such as dependence of the film thickness distribution on input power and change of the film thickness distribution over time due to target erosion. The dependence of the film thickness distribution on the input power is due to the fact that as the input power is increased, the power is more likely to concentrate on the plasma corresponding to the “twisted” portion of the film thickness distribution. The reason for this is not clear, but originally plasma tends to concentrate in the portion corresponding to “twist”, and the degree of concentration changes depending on the electric power. If the magnet unit is arranged so that a good thin film thickness distribution uniformity can be obtained at a certain input power, the thickness of the "twisted" part changes significantly when the input power is changed. A uniform film thickness distribution cannot be obtained. For this reason, the arrangement of each magnet unit is readjusted so that the magnetic field strength is increased in the thin film portion and the magnetic field strength is decreased in the thick film portion according to the input power. Therefore, the film thickness distribution can be made constant regardless of the input power. The change with time in the film thickness distribution due to target erosion is due to the fact that the target erosion speed is fast especially in the portion corresponding to the “twist” of the magnet units on the outermost both sides and is not constant in the target plane. This is because the electric power concentrates on the portion corresponding to the “twist” of the film thickness distribution, and the plasma density tends to increase. Since the target erosion rate is not constant, the T / M distance changes for each magnet unit as the film is formed over a long period of time. For this reason, the magnetic field intensity on the target surface changes, and the arrangement of the magnet unit that can obtain a good film thickness distribution uniformity is changed. In order to estimate the degree of erosion of the target, it is only necessary to monitor the input power during film formation and calculate the input integrated power. By re-adjusting the arrangement of each magnet unit according to the estimated target erosion amount, a film thickness distribution that does not change with time can be obtained.
[0032]
  In the configuration described in the specification and drawings of the present application, the configuration combining the mounting arrangement of the magnet unit described above.And film thickness measurement equipmenting. In this invention, it consists of a film thickness measuring instrument main body and a film thickness sensor, and the film thickness sensor is installed in a vacuum chamber. If a plurality of film thickness sensors are installed on the surface facing the sputtering cathode (where the substrate is installed), the film thickness distribution can be calculated from the output data of the film thickness measuring instrument. In order to obtain a desired film thickness distribution, feedback is applied to the magnet unit position control mechanism to adjust the position of each magnet unit. By performing this operation, it is possible to quickly obtain an optimal arrangement of the magnet units under each film forming condition. Since the erosion distribution of the target does not depend on the presence or absence of the substrate, if a film is formed on the substrate while maintaining the magnet unit arrangement determined in this way, the distribution is similar to the film thickness distribution obtained from the film thickness measuring instrument. Is realized on the substrate.
[0033]
  In the configuration described in the specification and drawings of the present application,One or more magnet units as a whole are periodically moved, and the relative position of the whole magnet unit being periodically moved with respect to the target is linked with the T / M distance control mechanism of the magnet unit.ing. When the reciprocating magnet unit approaches a target shield arranged around the target, the film thickness of the substrate portion facing the magnet unit approaching the shield becomes thin. This is because the drift electrons in the magnetron discharge forming the dense plasma are inhibited from moving by the target shield, so that the plasma density is reduced. For this reason, when the magnet unit approaches the target shield, the plasma density can be increased by bringing the magnet unit closer to the target side and further increasing the magnetic field strength, so that the film thickness of this portion does not decrease. . As a result, a thin film having an always good film thickness distribution can be obtained.
[0034]
【Example】
  Embodiments of the present invention will be described below with reference to the drawings.
[0035]
  FIG. 1 is a left half of a front sectional view showing the configuration of the sputtering cathode 1 of the first embodiment of the present invention, and FIG. 2R> 2 is a side sectional view showing the configuration of the sputtering cathode 1 of the first embodiment of the present invention. FIG. FIG. 3 is a view of the configuration of the sputtering cathode 1 of the first embodiment as viewed from the bottom. The structure of the sputtering cathode 1 will be specifically described with reference to this. The sputtering cathode includes a cathode body 5, a magnet unit 100, a target 2, a backing plate 10, and a water cooling jacket 8 that forms a water channel 9. The sputtering cathode 1 is attached via an insulator 6 to a vacuum wall 4 that forms a space in which sputtering is performed. The electric power applied at the time of sputtering is supplied from the DC variable power source 201 to the sputtering cathode 1.
[0036]
  The direction of attachment of the sputtering cathode 1 is as shown in FIG. 2, and the left side in the drawing is the L direction and the right side is the R direction.
[0037]
  The magnet unit 100 is connected to the magnet pedestal 180 via the support portion 181, the shaft 182, and the actuator 150. The shaft 182 transmits the operation output of the actuator 150 to the magnet unit 100. The magnet pedestal 180 is attached with a self-propelled slide unit 160 fitted to the ball screw 161 and can move along the guide 161. In this embodiment, four magnet units 100 are shown. These are collectively referred to as a magnet assembly 400.
[0038]
  The actuator 150 is attached to the magnet unit by a support portion 181 and a shaft 182 at an end portion of the magnet unit 100 in the rear surface RL direction.
[0039]
  The four slide units 160 attached to each magnet unit 100 normally operate in synchronization with each other, but can also operate independently.
[0040]
  For magnet unit 100, magnet numbers # 1 to # 4 are assigned for convenience.
[0041]
  The four magnet units 100 attached to the sputtering cathode 1 are moved along the direction 800 perpendicular to the target surface by the actuator 150. There are two types of movement. One is that the two actuators 150 (A) and (B) attached to the back surface RL of the magnet unit 100 are simultaneously at the same distance and along the direction 800 perpendicular to the target surface. Moving. Therefore, the T / M distances 310 (A) and (B) between the surface of the magnet unit 100 and the surface of the target 2 can be simultaneously changed while the surface of the magnet unit 100 and the surface of the target 2 are kept parallel. On the other hand, when the two actuators 150 (A) and (B) attached to the back surface RL portion of the magnet unit 100 move along the direction 800 perpendicular to the target surface, the movement of the actuator 150 in the R part or the L part is performed. If the amount is larger than the movement amount of the L part or the R part, the surface of the magnet unit 100 is consequently arranged obliquely with respect to the surface of the target 2 as shown in FIG.
[0042]
  Since the two actuators 150 are operated independently for each of the four magnet units 100, each magnet unit 100 is free in a space surrounded by the magnet base 180, the water cooling jacket 8, and the cathode body 5. It is possible to adopt a simple arrangement.
[0043]
  The four magnet units 100 attached to the sputtering cathode 1 can be moved by a slide unit 160 along a direction 801 parallel to the target surface. The slide unit 160 is self-propelled so that the magnet unit 100 can be arranged at an arbitrary position in the space formed by the cathode body 5.
[0044]
  Since the operation of the slide unit 160 is performed independently for each of the four magnet units 100, each magnet unit 100 can be arranged at an arbitrary position in the space formed by the cathode body 5. .
[0045]
  Further, the four magnet units 100 are independently moved in parallel to the target surface by the actuator 150 attached to the magnet unit 100 via the support portion 181 and the slide unit 160 attached via the magnet base 180. Thus, it is possible to take an appropriate arrangement so that a thin film having a uniform thickness can be obtained.
[0046]
  The actuator 150 and the slide unit 160 can be moved to the stored positions by the computer 200 and the controller 202.
[0047]
  FIG. 4 shows details of the actuator 150 used in this embodiment. The actuator 150 includes a cylinder 450 and a shaft 182, and the cylinder 450 is fixed to the magnet base 180. The cylinder 450 is hydraulically or pneumatically operated. The shaft 182 passes through a hole provided in the magnet pedestal 180 and is connected to the magnet unit via the support portion 181, and is not fixed to the magnet pedestal 180. The movement is along a direction 800 perpendicular to the target surface.
[0048]
  FIG. 5 shows a magnet unit 100 used in this embodiment. The magnet unit 100 is a rectangular magnet unit composed of an outer peripheral magnetic pole 101, a central magnetic pole 102 and a yoke 103. In the present embodiment, four magnet units 100 having the same specifications are used.
[0049]
  In FIG. 6, as another operation method of the present embodiment, the four magnet units 100 are synchronized and reciprocated along a direction 801 parallel to the target surface by the slide unit 160 and perpendicular to the target surface. The front sectional view of sputtering cathode 1 for explanation when moving each magnet unit independently along direction 801 is shown.
[0050]
  For convenience of explanation, FIG. 6 shows only one magnet unit 100 (# 1) corresponding to the leftmost side of FIG. Since other configurations of the sputtering cathode are the same as those of the first embodiment, the illustration is omitted.
[0051]
  FIG. 6A shows a case where the magnet unit 100 reciprocates along a direction 801 parallel to the target surface. FIG. 6A shows a case where the # 1 magnet unit 100 comes to the rightmost side in the drawing. FIG. Each of the states when # 1 magnet unit 100 comes to the left most toward the drawing is shown.
[0052]
  In the sputtering cathode of the first embodiment, when the swinging width of the magnet unit 100 is increased, the plasma generated by the outermost magnet unit 100 overlaps with the target shield 3, and the film thickness of this portion becomes thin. There is.
[0053]
  In order to solve this problem, the magnet unit 100 is brought closer to the target 2 side by the actuator 150 at the position shown in FIG. Further, the magnet unit 100 is moved away from the target 2 at the position of FIG. In this way, by changing the arrangement of the magnet unit 100 in accordance with the swing position of the magnet unit 100, a thin film having a uniform film thickness distribution can be obtained.
[0054]
  The method of changing the vertical arrangement of the magnet unit 100 according to the swing position of the magnet unit 100 is not limited to the above case.
[0055]
  FIG. 7 shows the result of plotting the film thickness distribution of a thin film deposited on a 360 mm × 465 mm substrate using the sputtering cathode 1 shown in FIGS. FIG. 7A shows a result obtained by using a conventional (Japanese Patent Laid-Open No. 6-192833) cathode, and FIG. 7B shows a result obtained by using the sputtering cathode of the example. The film thickness of the thin film is standardized at the thickest point in the substrate, and the film thickness is expressed as a percentage and displayed in contour lines. Reference numeral 601 denotes a contour line, and 602 denotes a film thickness.
[0056]
  The uniformity of the film thickness in FIG. 7A within the substrate surface was ± 11.1%. In addition, the film thickness rapidly decreases at both ends in the X-axis direction, and the film thickness distribution shape is not preferable.
[0057]
  On the other hand, the film thickness distribution (FIG. 7B) when using the sputtering cathode of the example is almost flattened in the substrate surface, and the uniformity of the film thickness distribution in the substrate surface is ± 3%. The arrangement of the four magnet units 100 at this time is as follows. First, the surface of each magnet unit 100 is respectively 4 mm, 2 mm, 2 mm, and 4 mm from the surface of each magnet base 180 in order of each magnet unit # 1 to # 4. Then, the L portion of the # 1 magnet unit 100 was moved 1 mm, and the R portion of the # 4 magnet unit 100 was further moved 1 mm closer to the target direction. The mounting intervals of the magnet units 100 of # 1 to # 4 were 20 mm, 10 mm, and 20 mm, respectively. By properly arranging the magnet unit attachments in this way, the film thickness distribution was flattened and the uniformity was greatly improved.
[0058]
  FIG. 8 is a front sectional view showing the structure of the sputtering cathode 1 of the second embodiment. The sputtering cathode, magnet unit, magnet unit position control mechanism and the like are the same as in the first embodiment.
[0059]
  This embodiment is different from the first embodiment in that the DC variable power source 201 is controlled by the computer 200.
[0060]
  When forming a thin film, the film thickness distribution of the thin film may change depending on the amount of power input from the DC variable power source to the sputtering cathode. In this case, the position of the magnet unit 100 is adjusted by controlling the actuator 150 and the slide unit 160 from the computer 200 via the controller 202 so as to obtain an appropriate film thickness distribution according to the input power of the DC variable power supply 201. .
[0061]
  Further, when the power is continuously turned on by the DC variable power source 201 and the target 2 is eroded, the film thickness distribution may show dependency on the supplied integrated power. In this case, the current flowing through the target at the time of discharge is monitored by the computer 200, and the computer 200 controls the actuator 150 and the slide unit 160 via the controller 202 so as to obtain an appropriate film thickness distribution from the change in the current. The position of the unit 100 is adjusted.
[0062]
  FIG. 9 is a front sectional view of the sputtering cathode of the third embodiment. Since the structure of the sputtering cathode is the same as that of the first embodiment, the description thereof is omitted.
[0063]
  The difference between this embodiment and the other embodiments is that the film thickness sensor 206 is installed in the film formation chamber, and the output of the film thickness meter 205 for measuring the film thickness is input to the computer 200. It is.
[0064]
  A quartz film thickness meter was used as the film thickness meter 205, and a quartz crystal resonator was used as the film thickness sensor 206.
[0065]
  The actuator 150 and the slide unit 160 are controlled by the computer 200 via the controller 202.
[0066]
  Magnetron discharge is caused by the electric power from the direct-current variable power source 201 and a gas such as Ar, and a thin film is formed on the film thickness sensors 206 installed in the vacuum chamber. The output signal of the film thickness sensor 206 is input to the film thickness meter 205 to know the film thickness. This value is input to the computer 200. The value of the film thickness sensor 206 installed at each location is taken into the computer 200, and feedback is applied from the computer 200 to the actuator 150 and the slide unit 160 via the controller 202 so as to obtain a desired film thickness distribution.
[0067]
  Since a non-contact type sheet resistance probe can be used as the film thickness sensor, the film thickness sensor is not limited to the above.
[0068]
  By adopting the configuration as described above, an appropriate magnet arrangement for obtaining a desired film thickness distribution can be determined.
[0069]
  Even if the first to third embodiments are combined, a thin film having a uniform film thickness distribution can be obtained.
[0070]
  In the present invention, the planar rectangular magnet unit is assumed to have the planar shape shown in FIGS. 10 (a) to 10 (e) in addition to the above embodiment. Reference numeral 101 denotes an outer peripheral magnetic pole, and reference numeral 102 denotes a central magnetic pole.
[0071]
【The invention's effect】
  Claim1According to the described invention, in the sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof, a mechanism for reciprocating the magnet unit in parallel with the target surface is attached to each magnet unit. By adopting the configuration, it is possible to easily adjust the optimal arrangement in each magnet unit and to obtain a thin film with good uniformity.
[0072]
  Claim2~4According to the invention, in a sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof, a mechanism for tilting the surface of the magnet unit with respect to the target surface, and the magnet unit reciprocating in parallel with the target surface. A mechanism for moving each of the magnet units, a mechanism for tilting the surface of the magnet unit with respect to the target surface in a sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof; and A structure in which a mechanism for moving the magnet unit in a direction perpendicular to the target surface and a mechanism for reciprocating the magnet unit in parallel with the target surface are attached to each magnet unit, and a plurality of planes on the target and the back surface thereof Sputtering cathode with a rectangular magnet unit In each of the magnet units, a mechanism for changing the distance between the target surface and the magnet unit is provided at both ends in the long side direction, and a mechanism for reciprocating the magnet unit in parallel with the target surface in each magnet unit By adopting any one of the configurations to which is attached, it is possible to easily adjust the optimal arrangement in each magnet unit, and to obtain a thin film with good uniformity.
[Brief description of the drawings]
FIG. 1 is a partial front sectional view showing a configuration of a sputtering cathode according to a first embodiment of the present invention.
FIG. 2 is a side sectional view of the same.
FIG. 3 is a bottom view of the same.
FIG. 4 is a detailed view of an actuator according to an embodiment.
FIG. 5 is a perspective view of a magnet unit according to an embodiment.
6A and 6B are diagrams for explaining the operation of the first embodiment. FIG.
7A and 7B are diagrams for comparing film thickness distributions, in which FIG. 7A is a film thickness distribution obtained by a conventional sputtering cathode, and FIG. 7B is a film thickness distribution obtained by a sputtering cathode according to the first embodiment.
FIG. 8 is a partial front sectional view showing a configuration of a sputtering cathode according to a second embodiment of the present invention.
FIG. 9 is a partial front sectional view showing a configuration of a sputtering cathode according to a third embodiment of the present invention.
FIGS. 10A to 10E are views showing a planar shape of a magnet unit that can be used in the embodiment.
FIGS. 11A and 11B are views for explaining a film thickness distribution by a conventional sputtering cathode. FIGS.
[Explanation of symbols]
1 Sputtering cathode
2 Target
3 Target shield
4 Vacuum wall
5 Cathode body
6 Insulator
7 Spacer
8 Water-cooled jacket
9 waterway
10 Backing plate
11 O-ring
100 Magnet unit
101 Peripheral magnetic pole
102 Central magnetic pole
103 York
150 Actuator
160 Slide unit
161 Guide
162 Ball screw
180 Magnet base
181 Supporting part
182 shaft
200 computers
201 DC variable power supply
202 controller
205 Film thickness meter
206 Film thickness sensor
310 T / M distance
400 Magnet assembly
450 cylinders
601 film thickness
602 contour lines
800 Direction perpendicular to target surface
801 Direction parallel to the target surface
900 Swing direction

Claims (5)

  A sputtering cathode comprising a target and a plurality of planar rectangular magnet units on the back surface thereof, wherein a mechanism for reciprocating the magnet unit in parallel with the target surface is attached to each magnet unit. .   In a sputtering cathode having a target and a plurality of planar rectangular magnet units on its back surface, there are a mechanism for tilting the surface of the magnet unit with respect to the target surface and a mechanism for reciprocating the magnet unit in parallel with the target surface. A sputtering cathode characterized in that it is attached to each magnet unit.   In a sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof, a mechanism for tilting the surface of the magnet unit with respect to the target surface, a mechanism for moving the magnet unit in a direction perpendicular to the target surface, A sputtering cathode, wherein a mechanism for reciprocating a magnet unit in parallel with a target surface is attached to each magnet unit.   In a sputtering cathode having a target and a plurality of planar rectangular magnet units on the back surface thereof, a mechanism for changing the distance between the target surface and the magnet unit is provided at both ends in the long side direction of each magnet unit. And a mechanism for reciprocating the magnet unit parallel to the target surface is attached to each magnet unit. The sputtering cathode according to any one of claims 1 to 4 , wherein the target has a planar rectangular shape.

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