JP2001338915A - Silicon part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicon part to be used in plasma equipment, which has a long life, chemical stability, non particle-generating characteristic, and is of high purity and of low cost, and to provide the plasma equipment. SOLUTION: The surface of the silicon part is at least partially coated with one or more materials selected among silicon carbide, silicon nitride, and diamond, with a thickness of 0.1 μm to 1 mm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a silicon component used in a plasma device for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art In the manufacture of semiconductor devices, as the degree of integration and the integration density of circuits increase, the dimensions of device wiring have become finer. Accordingly, the number of dry processing steps using plasma has been increasing. The process using the plasma includes a plasma etching process, a plasma CVD process, a sputtering process, and the like. In a plasma apparatus for performing these steps, the reaction chamber is exposed to plasma. The characteristics required for components exposed to the plasma include chemical stability, high purity, wear resistance (long life), non-dust generation, and the like.

In order to satisfy these characteristics, Japanese Patent Application Laid-Open No. Sho 62-281426 proposes to use a part made of glassy carbon in at least a part of a portion which comes into contact with plasma. Further, in order to extend the life of glassy carbon, Japanese Patent No. 2707886 proposes to coat diamond on the surface of an electrode plate of a plasma etching apparatus made of glassy carbon.

[0004] However, conventional glassy carbon parts cause a chemical reaction with a reaction gas (especially in the presence of oxygen ions) when used in a plasma etching process or the like, resulting in poor chemical stability and corrosion. It had the disadvantage of being fast and having a short life. Further, in the invention in which diamond is coated on the surface of an electrode plate made of glassy carbon, when a pinhole is generated due to a defect at the time of manufacturing in the diamond coating, or when the coating is peeled off with use, etc., There is a problem that corrosion of glassy carbon occurs. Further, in the case where a part of the component is chipped, the corrosion of the component further progresses, and there is a problem that the life may be shortened rather than the case where the diamond is not coated.

In order to achieve higher purity and longer life than glassy carbon, Japanese Patent Application Laid-Open No. Hei 2-20018 proposes to use single crystal silicon as a material for an electrode plate which is a component of a plasma apparatus. And JP-A-4-73936.
In the publication, polycrystalline silicon is adopted. Japanese Patent Application Laid-Open No. 4-326726 proposes that at least a part of the inner wall of the chamber is covered with a silicon-based material.

As described above, when silicon is used as a material of a component of a plasma apparatus, since it is the same material as a silicon wafer to be processed, it is not an impurity, is high in purity, and has higher chemical stability than glassy carbon. It had the advantage of being expensive and having a long life. However, there has been a strong demand for longer life and lower cost of plasma device components.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above problems, and is directed to a silicon component used in a plasma device, which has a longer life, chemical stability, An object of the present invention is to provide a silicon part and a plasma device which are excellent in dust generation, high in purity and low in cost.

[0008]

In order to achieve the above-mentioned object, the present invention relates to a silicon component used in a plasma apparatus, wherein at least a part of the surface is coated, wherein the coating is made of silicon carbide, silicon nitride. A silicon component coated with at least one selected from diamond and a thickness of 0.1 μm to 1 mm (claim 1).

[0009] As described above, a silicon component having at least a part of its surface coated with at least one selected from silicon carbide, silicon nitride, and diamond and having a thickness of 0.1 µm to 1 mm is a base material. Is made of the same material as the silicon wafer to be processed, so it is of high purity, has high chemical stability even when exposed to plasma, and has a surface with a coating that is more chemically stable to plasma. As a result, it has a longer life,
The generation of particles can be reduced, and the non-dusting property can be improved. Therefore, it is possible to improve the production yield and the productivity of the device.

In this case, a silicon electrode plate (Claim 2) in which the silicon component is installed at a position facing the wafer, or a silicon ring in which the silicon component is arranged around the wafer on the electrode side on which the wafer is mounted. (Claim 3). As described above, if the silicon component is a silicon electrode plate or a silicon ring, the silicon component itself is exposed to plasma with use, and the erosion by plasma is reduced due to the presence of a coating having high plasma durability on the surface, The life can be extended. Further, since generation of particles is reduced, contamination of a wafer to be processed can be suppressed.

In the case of the present invention, it is preferable that the silicon is single crystal silicon. As described above, if the silicon material is single-crystal silicon, the wafer is the same material as the wafer to be processed, so that contamination of the wafer due to contamination can be prevented. Further, it is superior to polycrystalline silicon in terms of mechanical strength, quality control, and the like, and is advantageously used as a material having high purity and long life.

[0012] A plasma device according to the present invention is provided with the silicon component. With such a plasma apparatus, it is possible to improve the production yield and productivity of semiconductor devices.

[0013]

Next, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto. The present inventors have conducted various studies on silicon components used in a plasma apparatus to have a longer life than ever, have excellent chemical stability, excellent non-dusting properties, and have high purity and low cost. As a result, the present inventors have found that a silicon component may be coated with a material having higher plasma resistance, and that the coating may have a desired thickness, thereby completing the present invention.

FIG. 1 is a schematic explanatory view showing an example of a plasma apparatus using the silicon component of the present invention. FIG. 2 is a diagram showing an example of a silicon electrode plate used in the plasma device of FIG. 1, and FIG. 3 is a diagram showing an example of a silicon ring used in the plasma device of FIG. Hereinafter, the silicon component of the present invention is exemplified by a silicon electrode plate provided at a position facing the wafer in the plasma apparatus of FIG. 1 and a silicon ring arranged around the wafer on the electrode side on which the wafer is mounted. This will be described in detail below.

First, a plasma etching apparatus 10 shown in FIG. 1 includes a chamber 11 in which a gas introduction system 12 and a discharge system 13 are connected, a lower electrode 14 installed in the chamber 11 and connected to a high frequency power supply. A silicon ring 2 is arranged around the silicon wafer W through the silicon ring W, and a silicon electrode plate 1 used as an upper electrode facing the silicon ring 2 is provided.

The silicon electrode plate 1 has a gas introduction system 12
The reaction gas sent to the internal gas container 15 through the gas introduction system 12 is ejected downward through the fine holes a, while being attached to the lower surface of the internal gas container 15 communicating with the internal gas container 15 through the mounting hole s. Further, a step r for arranging the wafer W is formed on the inner peripheral portion of the silicon ring 2 so that the generated plasma is focused on the wafer W.

Then, the wafer W to be processed is placed on the silicon ring 2 to which the high-frequency power is applied, and plasma is generated between the silicon ring 2 and the silicon electrode plate 1 by discharge, so that the surface of the wafer W is cleaned. Etching is performed.

Here, the feature of the silicon component according to the present invention is that at least a part of the surface has silicon carbide, silicon nitride,
Coated with at least one selected from diamonds, and the thickness of the coating is from 0.1 μm to
It is within a range of 1 mm. The use of such silicon components has a high plasma-resistant coating on the surface, so they have high chemical stability even when exposed to plasma, reduce the generation of particles, have excellent non-dusting properties, and have a long life. Can be achieved. Further, since the adhesiveness between the base material silicon and the coating is excellent, peeling of the coating hardly occurs. Furthermore, even if pinholes or peeling occur in these coatings, since the substrate is silicon, it does not become an impurity and has durability.

At this time, as a method of forming the coating film, a thermal vapor synthesis (CVD) method, a microwave CVD
Method, a high-frequency and direct-current discharge CVD method, an arc CVD method, a sputtering method and the like may be selected according to the material to be coated. The thickness of the coating may be in the range of 0.1 μm to 1 mm by appropriately adjusting the flow rate of the introduced gas, the atmospheric pressure, the reaction temperature and the like according to the above method.

When the thickness of the coating on the silicon part is 0.
When the thickness is less than 1 μm, the manufacturing cost is reduced, but pinholes are easily generated and the life is shortened. If the thickness is more than 1 mm, the production cost is increased, and the coating film is liable to be cracked or peeled off due to the difference in physical properties with the base material. Therefore, the thickness of the coating should be between 0.1 μm and
When the thickness is within the range of 1 mm, the life of the silicon member can be extended without causing peeling or cracking. The specific thickness may be set within the above range in consideration of the member shape and the purpose of use, and also in consideration of the manufacturing cost, the service life, the running cost, and the like.

Then, the coating of the silicon part is
It must be applied to at least the part exposed to the plasma, that is, at least when the silicon part is installed in a plasma device, it needs to be coated on the surface inside the reaction chamber. May be provided with a coating. For example, in the case of the silicon component of the plasma apparatus shown in FIG. 1, it is necessary to coat at least the lower surface of the silicon electrode plate exposed to the plasma, and the silicon ring at least the upper surface exposed to the plasma.

Further, silicon carbide and silicon nitride as the material of the film to be coated have high plasma resistance and contain silicon, so that they do not easily become impurities in a silicon wafer, and the production cost is relatively low. desirable. On the other hand, diamond has extremely excellent corrosion resistance and can have a long life. Therefore, these materials may be used alone, or may be used in combination to take advantage of the respective materials to form a composite membrane.

In the present invention, it is preferable that the material of silicon is single crystal silicon. Here, if the silicon material is single-crystal silicon, the same material as that of the wafer to be processed can be used, which does not cause contamination. Further, it is superior to polycrystalline silicon in terms of mechanical strength, quality control, and the like, and is advantageously used as a material having high purity and long life.

This single-crystal silicon can be usually manufactured by the Czochralski method, and according to this method, inexpensive and large-diameter single-crystal silicon is manufactured. If this single crystal silicon is used as a silicon part, it becomes the same material as the silicon wafer to be processed, which is the most preferable.

[0025]

EXAMPLES Examples and comparative examples of the present invention will be described below. Example 1 A disk having a diameter of 280 mm and a thickness of 5 mm was produced from a single crystal silicon ingot having a diameter of 300 mm.
0.5m diameter for jetting gas into the center of this disk
633 micrometer holes were formed, and twelve mounting holes for mounting the disk were provided on the outer peripheral portion, thereby producing an electrode plate shape as shown in FIG. After this processing, the surface was wrapped, and an acid treatment of HCl + H ₂ O ₂ and HF + HNO ₃ was performed. Thereafter, the surface was polished until it became a mirror state, and finally, HCl treatment, pure water cleaning, and IPA vapor drying were performed.

Next, the surface of the completed silicon electrode plate was treated with diamond particles having a diameter of 0.5 μm.
Thereafter, the electrode plate was placed in a chamber, and a diamond film was formed by using a hot filament CVD method using a gas obtained by mixing methane gas and hydrogen gas at a methane concentration of 2.0 vol% as a raw material. At this time, the gas pressure is 40T
orr and the substrate temperature were set at 900 ° C. After forming the film, the thickness of the diamond coating was measured and found to be 5 μm.

The diamond-coated silicon electrode plate thus obtained was set in a plasma etching apparatus, and was subjected to an etching treatment with a reactive gas CF ₄ + O ₂ .
With this silicon electrode plate, etching uniformity could be maintained even after 7,000 treatments. Also,
When the surface was observed during use, peeling of the coating was observed in part, but there was no phenomenon in which the number of particles increased, and no enlargement of the peeled part of the coating was observed.

(Example 2) An outer diameter of 260 mm and an inner diameter of 19 were obtained from a single crystal silicon ingot having a diameter of 300 mm.
A silicon ring of 5 mm x 3.4 mm thickness was made,
The step of providing a step for mounting a wafer on the inner peripheral portion was performed to produce a silicon ring shape as shown in FIG. After this processing, wrap the surface and add HCl
+ H ₂ O ₂ and HF + HNO ₃ were subjected to acid treatment. Then, the surface is polished until it becomes a mirror state, and finally HCl is added.
The treatment, pure water washing, and IPA vapor drying were performed.

Next, the surface of the completed silicon ring was treated with diamond particles in the same manner as in Example 1, and a diamond film was formed. Thereafter, the thickness of the coating was measured and found to be 5 μm. The etching treatment was performed on the diamond-coated silicon ring thus obtained in the same manner as in Example 1. With this silicon ring, uniformity of etching could be maintained even after 7,000 treatments.

Example 3 A silicon ring before coating on the surface was prepared in the same manner as in Example 2, and the completed silicon ring was set in a sputtering apparatus.
A sintered body of silicon carbide was set as a target material, and the pressure was reduced. Next, an Ar gas was introduced, the gas pressure was set to 1 × 10 ⁻¹ Torr, and the temperature of the silicon ring was set to 400.
Heated to ° C. Thereafter, sputtering was performed, and a silicon ring was coated on the silicon ring with a thickness of 50 μm. The silicon carbide-coated silicon ring thus obtained was subjected to the same etching treatment as in Example 1. With this silicon ring, uniformity of etching could be maintained even after 7,500 treatments.

Example 4 A silicon ring before coating on the surface was prepared in the same manner as in Example 2, and the completed silicon ring was set in a sputtering apparatus.
A silicon nitride sintered body was set as a target material, and the pressure was reduced. Next, an Ar gas was introduced, the gas pressure was set to 1 × 10 ⁻¹ Torr, and the temperature of the silicon ring was set to 400.
Heated to ° C. Thereafter, sputtering was performed, and a silicon ring was coated on the silicon ring with a thickness of 50 μm. The silicon nitride-coated silicon ring thus obtained was subjected to the same etching treatment as in Example 1. With this silicon ring, uniformity of etching could be maintained even after 7,000 treatments.

Example 5 A silicon ring before coating on the surface was prepared in the same manner as in Example 2, and the completed silicon ring was set in a sputtering apparatus.
A silicon nitride sintered body was set as a target material, and the pressure was reduced. Next, an Ar gas was introduced, the gas pressure was set to 1 × 10 ⁻¹ Torr, and the temperature of the silicon ring was set to 400.
Heated to ° C. Thereafter, sputtering was performed, and a silicon ring was coated on the silicon ring with a thickness of 50 μm.

Next, the surface of the completed silicon ring was treated with diamond particles having a diameter of 0.5 μm.
Thereafter, the ring was placed in a chamber, and a diamond film was formed by using a hot filament CVD method using a gas obtained by mixing methane gas and hydrogen gas at a methane concentration of 2.0 vol% as a raw material. At this time, the gas pressure is 40T
orr and the substrate temperature were set at 900 ° C. After forming the film, the thickness of the coating was measured to be 50 μm, and a composite film having a total thickness of 100 μm was obtained.

The composite film-coated silicon ring thus obtained was subjected to the same etching treatment as in Example 1. With this silicon ring, uniformity of etching could be maintained even after 10,000 times of processing.

Example 6 A silicon electrode plate before coating on the surface was prepared in the same manner as in Example 1, and the surface of the completed silicon electrode plate was treated with diamond particles to form a diamond film. The membrane was made. Thereafter, when the thickness of the coating was measured, it was 950 μm
Met. The diamond-coated silicon electrode plate thus obtained was subjected to an etching treatment in the same manner as in Example 1. This silicon electrode plate was able to maintain uniform etching even after 20,000 or more treatments.

(Comparative Example 1) Inner diameter 250 mm, length 300
A liquid furan resin and paratoluenesulfonic acid as a hardener were put into a steel molding cylinder sealed at one end of the mm, and the cylinder was sealed and mounted on a rotary drive centrifugal molding machine.
The raw material resin was rotated in a semi-cured state while being kept at a temperature of ° C. After the obtained semi-cured tubular resin was released from the mold, it was cut and developed, sandwiched between stainless steel plates, pressed with pressure, and then cured as it was. Next, the cured product was fired to 1,100 ° C. in a nitrogen atmosphere, and then heated to a high temperature to perform a graphitization treatment, thereby obtaining a glassy carbon substrate.

From this glassy carbon substrate, a diameter of 280 mm
X A disk having a thickness of 5 mm was prepared. At the center of the disk, 633 micro holes having a diameter of 0.5 mm for ejecting gas are bored, and at the outer periphery, 12 mounting holes for mounting the disk are provided, as shown in FIG. The shape of the electrode plate was prepared. After this processing, it was placed in an electric furnace to perform a purification treatment. After that, the surface is polished to a mirror state, and finally washed with pure water,
IPA vapor drying was performed.

The glassy carbon electrode plate thus obtained was subjected to the same etching treatment as in Example 1. In this electrode plate, the surface was severely degraded after approximately 4,000 treatments, so that uniformity of etching could not be maintained.

(Comparative Example 2) A glassy carbon electrode plate was prepared in the same manner as in Comparative Example 1, and the resulting glassy carbon electrode plate was placed in a CVD furnace and heated to 2000 ° C. to reduce the inside of the CVD furnace to 200 Torr or less. The pressure was reduced. At this time, a diamond film was formed to a thickness of 20 μm by flowing hydrogen and propane gas.

The diamond-coated glass-like carbon electrode plate thus obtained was subjected to the same etching treatment as in Example 1. When the number of times that the etching uniformity could be maintained was measured, about 5,000 treatments could be performed. When the surface was observed during use, peeling of the coating was observed in part. An increase in the number of particles was observed from the time this coating was peeled off, and the glassy carbon substrate on the back side of the part where the coating was peeled was greatly consumed when the uniformity of etching could not be maintained. Was done.

(Comparative Example 3) A silicon electrode plate having no coating on its surface was produced in the same manner as in Example 1, and the obtained silicon electrode plate was not subjected to film formation, and an etching process was performed in the same manner as in Example 1. went. In this electrode plate, about 5,000
Particles began to be generated after performing the process 0 times, and the uniformity of etching could not be maintained.

As in Examples 1 to 6, at least one selected from silicon carbide, silicon nitride, and diamond
Coated with seeds and the coating thickness is 0.1
The silicon part of the present invention, which is in the range of μm to 1 mm,
Excellent chemical stability, little peeling of the coating, and suppressed increase in the number of particles. In particular, when two types of the above materials are coated as in Example 5, and when the thickness of the coating within the above range is increased as in Example 6, the chemical stability is further excellent, The service life can be extended. On the other hand, Comparative Examples 1 to 3
As described above, the conventional parts other than the present invention had poor chemical stability and short life.

The present invention is not limited to the above embodiment. The above embodiment is an exemplification, and has substantially the same configuration as the technical idea described in the scope of the claims of the present invention. It is included in the technical scope of the invention.

For example, although a silicon electrode plate and a silicon ring have been described above as silicon components used in a plasma device, the present invention is not limited to this, and any silicon component used in a plasma device can be used. Also applicable to

Further, the plasma apparatus to which the silicon component of the present invention is applied is not particularly limited, and is an apparatus for performing processing using plasma, such as a plasma etching apparatus, a plasma CVD apparatus, and a sputtering apparatus. The present invention can be applied to any device as long as the component is exposed to plasma.

[0046]

As described above, according to the present invention, a silicon component used in a plasma apparatus is coated with at least one selected from silicon carbide, silicon nitride and diamond, and the thickness of the coating is reduced. By setting the thickness to 0.1 μm to 1 mm, it is possible to provide a high-purity, low-cost product that has a longer life, is excellent in chemical stability and non-dusting properties. Therefore, it is possible to improve the production yield and productivity of semiconductor devices.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing an example of a plasma device using a silicon component of the present invention.

FIG. 2 is a diagram showing an example of a silicon electrode plate used in the plasma device of FIG.

FIGS. 3A and 3B are views showing an example of a silicon ring used in the plasma apparatus of FIG. 1, wherein FIG. 3A is a plan view thereof and FIG.
Is a longitudinal sectional view thereof.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Silicon electrode plate, 2 ... Silicon ring, 10 ... Plasma etching apparatus, 11 ... Chamber, 12 ... Gas introduction system, 13 ... Discharge system, 14 ... Lower electrode, 15 ...
Internal gas container, a: fine hole, s: mounting hole, r: step, W: silicon wafer.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuyoshi Tamura 2-13-1, Isobe, Annaka-shi, Gunma Shin-Etsu Kagaku Kogyo Co., Ltd. Gunma Office (72) Inventor Keiichi Goto 2-chome, Isobe, Annaka-shi, Gunma 13-1 Shin-Etsu Kagaku Kogyo Co., Ltd. Gunma Plant F-term (reference) 4K030 FA01 GA02 KA14 KA30 KA47 5F004 BA04 BB32 BD05 DA01 DA26

Claims (5)

[Claims] 1. A silicon component used in a plasma apparatus, wherein at least a part of the surface is coated, wherein the coating is at least one selected from silicon carbide, silicon nitride, and diamond. A silicon part coated to a thickness of about 1 mm. 2. The silicon component according to claim 1, wherein the silicon component is a silicon electrode plate provided at a position facing the wafer. 3. The silicon component according to claim 1, wherein the silicon component is a silicon ring arranged around the wafer on the electrode side on which the wafer is mounted. 4. The silicon component according to claim 1, wherein the silicon is single-crystal silicon. 5. A plasma device comprising the silicon component according to claim 1. Description: