JP7417367B2 - Parts for film deposition equipment and film deposition equipment equipped with the same - Google Patents

Description

The present invention relates to a component for a film forming apparatus that has excellent adhesion of a deposited film and an effect of relieving peeling stress, and a film forming apparatus equipped with the same.

In recent years, semiconductor products have been manufactured using various film forming methods (e.g., sputtering, CVD, etc.) on objects to be processed (e.g., Si substrates, etc.) in a film forming chamber with a reduced pressure atmosphere. Manufactured by forming. At that time, the film formed on the target object to be processed does not adhere to various parts of the film forming equipment that are present around the object to be processed during film formation in the film forming chamber. Inevitable.

Such a phenomenon becomes more obvious as the number of times of film formation (number of batches) increases. That is, while the object to be processed is usually replaced for each film-forming operation, the various parts of the film-forming apparatus that are present around the object to be processed are not replaced for each film-forming operation. As a result, as the film-forming operation is repeated, the deposited films overlap for the number of times (batch number) of film-forming, that is, a thick film is deposited on the parts for the film-forming apparatus. Therefore, when the film attached to the parts of the film forming apparatus exceeds the critical point of adhesion, it peels off and falls off, becoming particles such as fine particles and dust, which float inside the film forming chamber and form the film. Contaminates the inside of the membrane chamber. If such particles are taken into semiconductor products, there is a risk that the yield of semiconductor products will be significantly reduced.

In order to solve this problem, conventional film-forming equipment has specifications in which various sprayed films are provided on the surfaces of parts of the film-forming equipment placed in the film-forming chamber (Patent Document 1). .
It is known that a thermal sprayed film generally has a larger surface roughness than a blast-treated surface, so that a film deposited on the thermal sprayed film (hereinafter referred to as an adhered film) tends to have an anchoring effect. Furthermore, since the sprayed film has a large contact area with the deposited film, it tends to be difficult to peel off. Furthermore, it is also known that the sprayed film has a certain degree of porosity, and the presence of the pores makes it slightly deformable, and the peeling stress of the deposited film is alleviated depending on the degree of deformation.

However, a satisfactory effect has not always been obtained for sputtered films whose deposited films have high internal stress. That is, as mentioned above, when the sputtered film is repeatedly deposited and becomes thick, the sputtered film attached to the parts for the film forming apparatus tends to exceed the critical point of adhesion, peeling off, falling off, and so on. Particles such as fine particles and dust are generated and float inside the film forming chamber, causing the problem of contaminating the inside of the film forming chamber.
For this reason, there have been expectations for the development of parts for film forming apparatuses that are less prone to peeling or falling off of deposited films with high internal stress, and film forming apparatuses equipped with the same.

Patent No. 4382532

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a component for a film forming apparatus that is unlikely to cause peeling or falling off of an adhered film with high internal stress, and a film forming apparatus equipped with the same. With the goal.

In order to solve the above problem, the invention according to claim 1 provides an Al alloy containing 4.81 to 11.6 at% Si (however, Bi, Ce and Mg are not included) on the surface exposed to the film forming atmosphere. Parts for film forming equipment on which a thermal sprayed film is formed of an Al alloy containing 1.1 to 2.9 at% Ti (excluding that containing Bi, Ce, and Mg) The thermal sprayed film is formed in a single layer on the surface of the part for the film forming apparatus , and another thermal sprayed film is not additionally laminated on the thermal sprayed film, and the thermal sprayed film is It is characterized in that the surface roughness Ra [μm] is within the range of 50 to 70, and the adhesion force [N/mm ² ] of the sprayed film is 6 or more.

The invention according to claim 2 provides a film forming apparatus comprising a film forming chamber and a part for the film forming apparatus disposed in the film forming chamber and having a thermally sprayed film formed on a surface thereof, wherein the thermally sprayed film is , an Al alloy containing 4.81 to 11.6 at% Si (excluding Bi, Ce and Mg) or an Al alloy containing 1.1 to 2.9 at% Ti (however, (excluding containing Bi, Ce and Mg) , the thermal sprayed film of only a single layer is formed on the film forming apparatus component, and another thermal sprayed film is additionally formed on the thermal sprayed film. It is characterized in that it is not laminated, the surface roughness Ra [μm] of the sprayed film is within the range of 50 to 70, and the adhesion strength [N/mm ² ] of the sprayed film is 6 or more .

The part for a film forming apparatus according to claim 1 is provided with an Al alloy containing 4.81 to 11.6 at% Si (but not including Bi, Ce and Mg) on the surface exposed to the film forming atmosphere. ) or an Al alloy containing 1.1 to 2.9 at% Ti (excluding Bi, Ce, and Mg) , and the surface roughness of the sprayed film is Ra [μm] is within the range of 50 to 70, and the adhesion force [N/mm ² ] of the sprayed film is 6 or more . As a result, it is possible to obtain a component for a film forming apparatus in which peeling or falling off does not easily occur with respect to a deposited film with high internal stress.

In the film forming apparatus according to claim 2 , the parts for the film forming apparatus disposed in the film forming chamber have a thermally sprayed film formed on the surface thereof, and the thermally sprayed film contains 4.81 to 11.6 at% Si. Al alloys containing (however, excluding those containing Bi, Ce and Mg) or Al alloys containing 1.1 to 2.9 at% Ti (however, excluding those containing Bi, Ce and Mg) The thermal sprayed film had a surface roughness Ra [μm] in a range of 50 to 70 , and an adhesion force [N/mm ² ] of 6 or more . As a result, the thermally sprayed film provided on the surface of the part for the film forming apparatus is less likely to peel off or fall off compared to the adhered film with high internal stress, thereby suppressing the generation of particles. The present invention contributes to the provision of a film forming apparatus that can obtain this effect even when the deposited film is a sputtered film with high internal stress.

1 is a schematic configuration diagram showing an example of a film forming apparatus according to an embodiment of the present invention. FIG. 1 is an enlarged sectional view of a main part showing an example of a component for a film forming apparatus according to an embodiment of the present invention. A schematic diagram explaining the arc spraying method.

FIG. 1 is a schematic configuration diagram showing a sputtering apparatus as an example of a film forming apparatus 10 according to the present embodiment. The vacuum chamber 1 is entirely made of stainless steel (for example, SUS304), and the internal space of the vacuum chamber 1 constitutes a film forming chamber 20. A process gas introduction pipe 8 connected to a process gas supply means (not shown) and an exhaust pipe 9 connected to a vacuum evacuation means (not shown) are connected to the film forming chamber 20 at a position opposite thereto. The film forming chamber 20, which is the internal space of the vacuum chamber 1, is evacuated through an exhaust pipe 9 by an exhaust means (not shown).

In the film forming chamber 20, a target T that is electrically connected to the high frequency power source 2 and functions as a cathode, and a substrate holder 4 that functions as an anode are arranged facing each other in parallel. Behind the target T, a cylindrical magnet 6 is placed in the center and an annular magnet 6' is placed in the outer periphery so that their polarities are opposite to each other. leaks to the surface and is parallel to the surface in question. A substrate W is placed on the substrate holder 4, and a bias power source (not shown) is electrically connected to the substrate holder 4. A temperature control means 5 is arranged behind the substrate holder 4 to control the substrate W to a predetermined temperature.

A space between the substrate W and the target T is rotatable in a plane parallel to the substrate W, and the position is changed between a position where film formation can be performed on the substrate W and a position where film formation is blocked. The shutter plate 7 is arranged like this. The shutter plate 7 is made of stainless steel (for example, SUS340).

The shutter plate 7 is one of the parts for the film forming apparatus according to this embodiment. FIG. 2 is an enlarged sectional view of a main part of the shutter plate 7. As shown in FIG. The shutter plate 7 has a sprayed film 3 made of Al or an Al alloy formed on the surface exposed to the film forming atmosphere in the film forming chamber 20 . The surface roughness Ra [μm] of the sprayed film 3 is within the range of 50 to 70.

When the sprayed film 3 is an Al alloy, the additive element is preferably Si or Ti. When the sprayed film 3 is a Cu alloy, the additive element is preferably Al.

As the thermal spraying method, an arc thermal spraying method, a flame thermal spraying method, a plasma thermal spraying method, etc. can be used, but the arc thermal spraying method is preferable in order to realize the present invention. According to the arc spraying method, a sprayed film 3 having a surface roughness Ra [μm] within the range of 50 to 70 and an adhesion force [ N/mm ² ] of 6 or more can be formed. As a result, it is possible to obtain a component for a film forming apparatus in which peeling or falling off does not easily occur with respect to a deposited film with high internal stress.

FIG. 3 is a schematic diagram illustrating the arc spraying method.
Arc spraying is a process in which a predetermined distance between two spray coating wires is generated in order to generate a DC arc discharge at the tips of two spray coating wires that are continuously fed in the direction of the arrow. By applying voltage/current, arcing is generated near the tips of the two thermal spray materials. At the same time, compressor air is used to atomize the metal melted by arcing. These atomized particles (Arc spray particles) are deposited on a target substrate (not shown) by spraying them onto the target substrate (not shown) through an opening provided in an air cap. , a desired thermal sprayed film 3 is formed. As the blowing gas, for example, air, nitrogen gas, argon gas, etc. are suitably used.

The present inventors found that the hole diameter of the opening provided in the air cap has the following tendency, and selected suitable conditions for the present invention.
The smaller the hole diameter of the opening provided in the air cap, the higher the pressure inside the air cap, and the more fine the atomization becomes possible. As a result, the sprayed film 3 formed on the target base material tends to have low surface roughness and high adhesion.
On the other hand, if the hole diameter of the opening provided in the air cap is increased, the pressure inside the air cap will decrease and atomization will not proceed. For this reason, the sprayed film 3 formed on the target base material has a large surface roughness and tends to have low adhesion.

The present inventors investigated contradictory conditions, that is, thermal spraying conditions for producing a thermal sprayed film 3 that tends to have large surface roughness and high adhesion.
As for the thermal spraying conditions for producing a thermal sprayed film 3 made of Al having surface roughness Ra and adhesion within such a range, it is preferable that the hole diameter of the air cap is large. It is preferable that the voltage be as low as possible within a range that allows stable arcing. The gas pressure is desirably as low as possible without reducing the adhesion of the sprayed film 3. Specifically, the voltage [V] is 30 to 33, the current [A] is 150 to 200, the gas type is air, argon, or nitrogen, the gas pressure [bar] is 28 to 35, and the air cap hole diameter [mm]. and φ12 to φ14, respectively.

Examples of the base material used when forming the sprayed film 3 made of Al or Al alloy by the above-mentioned arc spraying method include SUS, Al, Ti, and various ceramics. The surface roughness Ra [μm] of the base material is preferably within the range of 3 to 8.

In the film forming apparatus 10 configured as described above, by maintaining the inside of the film forming chamber 20 in an argon atmosphere of, for example, about 10 ⁻³ to 10 ⁻¹ Pa, and applying high frequency power to the target T using the high frequency power source 2, A glow discharge is effectively generated in a portion above the target T where the electric field and magnetic field are perpendicular to each other, and plasma is generated in an annular shape. Ar ⁺ ions in this plasma are accelerated near the target T, which is the cathode, and collide with the surface of the target T, sputtering target atoms, so that the sputtered particles are deposited on the substrate W of the substrate holder 4, which is the anode. It adheres to form the desired thin film.

The shutter plate 7 closes the gap between the target T and the substrate W at the start of sputtering, and a film of sputtered particles adheres to the shutter plate 7. When sputtering reaches a steady state, film formation on the surface of the substrate W is started by rotating the shutter plate 7 to open the space between the target T and the substrate W. At this time as well, a similar film is formed on the shutter plate 7 near the substrate W.

When the substrate W is formed to a predetermined thickness, it is replaced with the next substrate and sputtering is continued. Since the shutter plate 7 is continuously used as it is, the film attached to the shutter plate 7 gradually becomes thicker as sputtering is repeated, but in this embodiment, as described above, the film attached to the shutter plate 7 is In addition, since the thermal sprayed film 3 made of Al is formed, the adhesion of the adhered film to the thermal sprayed film 3 can be improved, and peeling stress can be further alleviated, making it difficult to peel off the adhered film. As a result, it is possible to suppress contamination in the film forming chamber 20 due to particles generated due to peeling of the adhered film. The sprayed film 3 having the above structure is made of a Ta film, a TaN film, a Ti film, a TiN film, a W film, a WN film, a WSi film, an SiN film, and a laminated layer thereof, which have a relatively large internal stress that causes peeling. Effective against film adhesion.

Furthermore, the sprayed film 3 having the above structure is not easily oxidized even when placed in the atmosphere, and can maintain the above-mentioned characteristics for a long period of time. As a result, the maintenance cycle of the film forming apparatus can be extended, the operating rate of the film forming apparatus can be improved, and productivity can be increased.

In addition, before examining the above-mentioned arc thermal spraying method, the present inventors also investigated flame thermal spraying method and plasma thermal spraying method for comparison. As a result, the following trends were confirmed.
Since flame spraying is a method of spraying wire while melting it, it is difficult to arbitrarily adjust the amount of melting. Therefore, the sprayed film 3 formed on the target base material has low surface roughness and a uniform surface profile.
In the plasma spraying method, the material used is particles of about several tens to 100 μm, which are melted by a plasma flame, sprayed, and deposited on the target substrate to form the sprayed film 3. At that time, the particles are completely melted by the high heat of the plasma and have a high heat content. Therefore, when deposited on the target substrate, the particles are large and flat, and a sprayed film 3 with small surface roughness and a uniform surface profile is formed.

Therefore, in the flame spraying method and the plasma spraying method, it is impossible to obtain the above-mentioned contradictory conditions of the present invention, that is, the spraying conditions for producing a sprayed film 3 that tends to have large surface roughness and high adhesion. Do you get it. Specifically, the flame spraying method and the plasma spraying method can only provide a sprayed film 3 with a surface roughness Ra of about 8 to 20 μm. It was confirmed that the arc spraying method of the present invention is essential for roughening the sprayed film 3.

<Example 1>
In Example 1, a SUS304 base material with a planar dimension of 80 mm x 100 mm and a thickness of 2 mm was used, and a sprayed film 3 (thickness: 350 μm) made of Al alone was formed on the surface thereof using an arc spraying method. Before forming the sprayed film, the surface of the SUS304 base material was dry blasted to roughen the surface so as to obtain an anchor effect. The thermal spraying method was an arc thermal spraying method. Four samples (Al-1, Al-2, Al-3, Al-4) having different thermal spraying conditions as shown in Table 1 below were prepared.
Separately from these, a sprayed film made of an Al alloy containing Si or Ti as an additive element was also produced. At that time, the Si content was in the range of 4.81 to 11.6 at%, and the Ti content was in the range of 1.1 to 2.9 at%.

<Comparative example 1>
In Comparative Example 1, a thermally sprayed film made of simple Al was formed on the surface of the same base material as in Example 1 by flame spraying so as to have the same thickness (thickness 350 μm). One sample (Ref.Flame Al) shown in Table 1 described below was produced.

<Example 2>
In Example 2, the same base material as in Example 1 was used, and a sprayed film 3 (thickness: 350 μm) made of a Cu--Al alloy was formed on the surface thereof using an arc spraying method. The composition of the Cu--Al alloy was Cu-7.9 at% Al. As in Example 1, the surface of the base material was roughened by dry blasting in advance to obtain an anchor effect before forming the sprayed film. The thermal spraying method was an arc thermal spraying method. Two samples (Cu-Al-1 and Cu-Al-2) with different thermal spraying conditions shown in Table 1 described below were prepared.
Separately from these, a Cu film containing no additive elements (a sprayed film made of pure Cu) and a sprayed film made of a Cu--Al alloy were also produced. At that time, the Al content of the sprayed film made of the Cu--Al alloy was within the range of 6.7 to 11.1 at%.

Table 1 shown below shows the production conditions of each sample produced in Example 1, Comparative Example 1, and Example 2, and evaluation of the sprayed coatings formed. The surface roughness Ra was evaluated using a stylus surface roughness measuring device (manufactured by Tokyo Seimitsu Co., Ltd., model number: SURFCOM TOUCH50) under the conditions specified in JISB0601 (1994). The adhesion was evaluated using a pull-off adhesion tester (manufactured by ELCOMETER, model number: 510) under the conditions specified in JIS K5600-5-7 .

The following points became clear from the evaluation of the formed sprayed film.
(a1) By using the arc spraying method, it is possible to form a sprayed film with a larger Ra and greater adhesion than samples produced by the flame spraying method (comparison of sample number 1 and sample number 2) .
(a2) In the sprayed film made of Al alone, the surface roughness [μm] is within the range of 15 to 70, and the adhesion force [ N/mm ² ] is within the range of 6.51 to 7.11. (Sample numbers 2 to 5).
(a3) For a sprayed film made of Cu-Al alloy, the surface roughness [μm] is within the range of 20 to 60, and the adhesion force [ N/mm ² ] is within the range of 6.08 to 8.82. (Sample numbers 6-7).
(a4) It has been found that when the surface roughness of the sprayed film exceeds the above range, the strength of the sprayed film decreases, sprayed particles begin to fall off, and the amount of particles generated increases.
(a5) The desired surface roughness cannot be secured unless the sprayed film has a thickness of 300 to 600 μm (comparison of sample number 2 and sample numbers 3 to 5).
(a6) From the adhesion evaluation results, it was found that increasing the thickness of the sprayed film increases the amount of stress absorption (a sprayed film with high strength can be obtained).

Although not shown in Table 1, it was confirmed that when the roughness Ra was greater than 70 μm, it became difficult to ensure adhesion between the sprayed particles.
Although not shown in Table 1, the same results as the above-mentioned sprayed films made of Al alone (sample numbers 2 to 5) were obtained with the sprayed films made of Al alloys with Si or Ti added as an additive element. In addition, the same results as the above-mentioned thermal sprayed films made of Cu--Al alloy (sample numbers 6 to 7) were obtained for the thermally sprayed films made of Cu alone.

From the above evaluation results, the sprayed film made of Al alone or Al alloy according to the present invention formed using the arc spraying method has a higher surface area than the sprayed film made of Al alone formed by the conventional flame spraying method. It was found that the roughness was large and the adhesion was large. As a result, by providing the sprayed film made of Al alone or an Al alloy according to the present invention, high adhesion to the deposited film and high peel stress relaxation effect can be stably obtained over a long period of time.
Furthermore, the same actions and effects as the sprayed film made of Al alone or an Al alloy were confirmed for the sprayed film made of Cu alone or Cu alloy according to the present invention, which was formed using the arc spraying method.
Therefore, the present invention contributes to providing a component for a film forming apparatus that is less likely to cause peeling or falling off of a deposited film with high internal stress, and a film forming apparatus equipped with the same.

By using the sprayed film of this embodiment, the integrated power required to generate particles that contaminate the inside of the film forming chamber in a sputtering device was conventionally 75 kWh for Ti/W laminated film and 300 kWh for W/WN laminated film. It has become possible to increase the power consumption to 150kWh using a Ti/W multilayer film and 600kWh using a W/WN multilayer film.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications can be made based on the technical idea of the present invention.

The present invention is applicable not only to sputtering apparatuses but also to other film forming apparatuses such as CVD apparatuses and vapor deposition apparatuses. Furthermore, the atmosphere during film formation is not limited to reduced pressure, but may be atmospheric pressure.

Parts for a film forming apparatus according to the present invention include not only a shutter plate but also a shower plate, a deposition prevention plate, a mask, an earth shield, a substrate holder, and the like.

INDUSTRIAL APPLICABILITY The present invention can be widely applied to parts for film forming apparatuses in which peeling or falling off does not easily occur with respect to adhered films with high internal stress, and to film forming apparatuses equipped with the same.

1 Vacuum chamber, 3 Sprayed film, 7 Film forming device parts (shutter plate), 10 Film forming device, 20 Film forming chamber, T target, W substrate.

Claims (2)

An Al alloy containing 4.81 to 11.6 at% Si (excluding those containing Bi, Ce, and Mg) or 1.1 to 2.9 at% Ti is placed on the surface exposed to the film forming atmosphere. A part for a film forming apparatus on which a thermal sprayed film made of an Al alloy containing (excluding that containing Bi, Ce and Mg) is formed,
The thermal sprayed film of only a single layer is formed on the surface of the part for the film forming apparatus ,
Another thermal sprayed film is not additionally laminated on the thermal sprayed film,
The surface roughness Ra [μm] of the sprayed film is within the range of 50 to 70,
A component for a film forming apparatus, characterized in that the thermal sprayed film has an adhesion force [N/mm ² ] of 6 or more. A film forming apparatus comprising a film forming chamber and parts for the film forming apparatus disposed within the film forming chamber and having a thermally sprayed film formed on a surface thereof,
The sprayed film is made of an Al alloy containing 4.81 to 11.6 at% Si (excluding Bi, Ce, and Mg) or an Al alloy containing 1.1 to 2.9 at% Ti. Consisting of an alloy (excluding those containing Bi, Ce and Mg),
The thermal sprayed film of only a single layer is formed on the part for the film forming apparatus,
Another thermal sprayed film is not additionally laminated on the thermal sprayed film,
The surface roughness Ra [μm] of the sprayed film is within the range of 50 to 70,
A film forming apparatus characterized in that the thermal sprayed film has an adhesion force [N/mm ² ] of 6 or more.

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