JPH05235149A - Adhesion-preventive plate and inner jig - Google Patents

Abstract

PURPOSE:To obtain an adhesion-preventive plate which is scarcely peeled even on film having a strong internal stress to be adhered, has small discharge gas and a light weight by exposing an SiO layer having surface roughness on its surface and specifying the thickness of an SiC layer and the roughness. CONSTITUTION:A surface of an adhesion-preventive plate made of silicon carbide (SiC) is roughed, for example, to roughness of 10-100mum by mechanical machining such as blasting for deleting the surface by injecting alumina particles. Further, a high density SiC layer 13 having a uniform thickness of 100-1000mum is provided on the surface by a CVD method. Graphite is used as a base material of an adhesion-preventing agent, and the adhesion-preventing agent coated with SiC may be used as a base on a surface of the base material. Thus, it is scarcely peeled even on a film having a strong internal stress to be adhered.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of an adhesion preventive plate and an internal jig which are provided in a forming chamber of a thin film forming apparatus and cover a portion other than a desired thin film forming region.

[0002]

2. Description of the Related Art Generally, when manufacturing a semiconductor integrated circuit device or the like, a sputtering apparatus or C for forming a thin film on a substrate or the like.
There is a thin film forming apparatus such as a VD apparatus.

FIG. 3 shows the structure of a general sputtering apparatus. In the chamber 1 of the sputtering device,
An upper electrode 3 having a target 2 attached thereto is suspended, and a lower electrode 6 on which a substrate 5 to be processed is placed is provided in the lower portion so as to face the upper electrode 3. An atmosphere region into which a predetermined process gas is introduced is formed between the upper electrode 3 and the lower electrode 6, and the substrate 5 to be processed is placed on the lower electrode 6 in the atmosphere to generate plasma to generate a substrate to be processed. A thin film is formed on No. 5.

When forming this thin film, in addition to the substrate to be processed in the chamber, a wall surface in contact with a predetermined atmosphere region,
An undesired thin film (hereinafter referred to as an adhering film) is also formed on an internal jig such as the shutter 7 and the transport mechanism. In order to prevent this, so as to cover a desired portion in the chamber 1,
A deposition preventive plate 8 is provided. Generally, such a deposition preventive plate, a shutter and the like are made of a stainless material in consideration of heat resistance, strength, released gas and the like.

Therefore, in such a sputtering apparatus, M
When a target made of refractory metal such as o or Ti is mounted and a process gas such as oxygen or nitrogen is introduced into the atmosphere to form a thin film of boride carbide, nitride, oxide or silicide on the substrate to be processed. In this case, an adhesion film of a high melting point metal is also formed on the adhesion preventing plate 8.

The surfaces of the deposition preventive plate 8 and the internal jig are roughened by blasting or the like so that film peeling is less likely to occur. Particularly, the high melting point metal adhesion film is made of stainless steel. It is not fused and is simply attached, so it is easy to peel off.

When the substrate to be processed is attached or detached, the inside of the chamber 1 is exposed to the atmosphere, and a rapid temperature change is repeatedly applied to the adhered surface thereof. Due to the difference in the coefficient of thermal expansion of, the peeling of the adhered film occurs. FIG. 4 is a diagram showing film peeling when the adhered film adheres to the shutter plate by about several tens of μm.

Usually, when forming a thin film, after plasma is generated (pre-sputtering) between both electrodes in a nitrogen atmosphere,
The shutter plate 7 is rotated, and thin film formation is started on the substrate to be processed. Therefore, as shown in the drawing, the TiN film 9 (30 μm) is formed on the surface of the shutter plate 7, and the crack 9a and the peeling film 9b are generated due to the external factors as described above.

The film of the high melting point metal that has been once peeled off is more likely to be a small piece than aluminum or the like, and floats or moves every time each mechanical section is operated, so that it adheres to the processed surface of the substrate to be processed. Adhere to.

In addition to this, as a technique for imparting surface roughness,
The molybdenum (Mo) spraying method can be mentioned, which is a method of spraying molybdenum on an adhesion-preventing plate and an internal jig to form a layer having a porous structure on the surface and making it adhere to the layer to make it difficult to peel off. ing.

Since all of the methods only make it difficult to remove the adhesion film, the adhesion prevention plate and the internal jig are washed before the adhesion film formed on the adhesion preventing plate and the internal jig is separated. Then, the adhered film was removed.

[0012]

However, in the above-mentioned cleaning of the adhesion-preventing plate and the internal jig, when repeatedly cleaned, the surface having the unevenness becomes gradually smoother, and the film peeling than that used last time. Is more likely to occur. Therefore, it is necessary to reapply the surface roughness, and the blasting process and the like other than the cleaning are included, and the cleaning process is complicated. In addition, the cleaning cycle (maintenance cycle) becomes faster as the amount of thin film formed by production increases.

Further, if the thin film forming apparatus is an apparatus for forming a thin film by utilizing a vacuum state as an atmosphere, the inside of the chamber is exposed to the atmosphere when the substrate is mounted and demounted, and the gas and water contained in the atmosphere are attached to the deposition preventive plate. Adsorb to. When the inside of this chamber is evacuated to the ultimate vacuum, for example, the more the adsorbed gas and water, the more the released amount, and thus the evacuation time becomes longer.

Therefore, as the number of times of attachment / detachment for cleaning the deposition preventive plate and the internal jig increases, the time required for exhausting increases and the operating rate of the thin film forming apparatus decreases. The stainless steel material is heavy from the viewpoint of workability of attachment and detachment, and it requires labor to attach it.

Further, in the Mo spraying method, since the formation layer has a porous structure as described above, the atmosphere is adsorbed,
Also in terms of released gas, it is not desirable as a deposition preventive plate or an internal jig. Therefore, it is an object of the present invention to provide a light-weight deposition preventive plate and an internal jig which are less likely to be peeled off even when a film having a strong internal stress is attached, and which emits less gas.

[0016]

In order to achieve the above object, the present invention forms a thin film in a predetermined atmosphere provided with an adhesion preventing means for preventing film formation in an undesired region other than a substrate to be processed. In a device, a SiC layer having a surface roughness is exposed on the surface, the SiC layer has a film thickness of 100 to 1000 μm, and the surface roughness is 10 to 100 μm. ..

[0017]

Since the adhesion-preventing plate and the internal jig having the above-mentioned structure are coated with the SiC film on the surface, the corrosion resistance against chemicals (acid) becomes strong and even if cleaning is performed to remove the adhered film. The initial surface roughness is maintained, the coefficient of thermal expansion is small, the gas has the characteristics of released gas, and it is lighter in weight than stainless steel.

[0018]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1A shows a sectional view of an adhesion-preventing plate made of silicon carbide (hereinafter referred to as SiC) as a first embodiment according to the present invention. On the surface of the deposition preventive plate 11, for example,
Roughness of 10 to 100 μm is applied to the surface by mechanical processing such as blasting in which alumina particles are jetted to scrape the surface. However, it is not easy to form a deposition preventive plate or the like from SiC, and the strength is also fragile. Further, regarding the roughness applied to the surface, when the roughness is small, the surface becomes smooth (flat) and easily peels off, and when the roughness is too large, a sufficient effect cannot be obtained. Therefore, based on the relationship between the results of Examples described later and machining, the range considered to be optimum is 10 to 1
The roughness was set to 00 μm.

FIG. 1B shows the Si shown in the first embodiment.
As a second embodiment in which the strength of the C deposition preventive plate is improved, a cross-sectional view of a deposition preventing plate in which a core base material is used for the deposition preventing plate and the surface of the base material is coated with SiC is shown. In the second embodiment, graphite is used as a base material, and the surface of the graphite plate 12 is subjected to the above-mentioned machining to give a roughness of 10 to 100 μm.
Further, by the CVD method, 100-100 on the surface
A high density SiC film 13 having a uniform film thickness of 0 μm is formed.

FIG. 1 (c) is a sectional view of the SiC deposition preventive plate of the third embodiment. In the second embodiment, the base material surface was roughened, but in the third embodiment, the base material surface was not roughened, and the high density SiC film 13 formed on the base material 14 surface was described above. Similarly, a roughness of 10 to 100 μm is applied by machining. In this embodiment, since the formed high-density SiC film 13 is directly provided with the roughness, a desired accuracy of the roughness can be obtained as compared with the second embodiment. The deposition preventive plate and the internal jig, on which the high-density SiC film having the desired roughness is formed on the surface as described above, will be specifically described by taking the second embodiment as an example.

As described above, the surface of the graphite 12 of the adhesion-preventing plate base material is roughened to about 50 μm, and then the CVD method is used.
A high-density SiC film 13 having a uniform film thickness of 500 μm is formed. TiN is continuously applied to the surface of this adhesion preventive plate to
It was confirmed that there was no peeling even after forming a film of about m.

Further, in the embodiment, the anti-adhesion plate has been described, but the same effect can be obtained by forming the SiC film or coating the surface of the internal jig such as the shutter and the portion where adhesion should be prevented. ..

Next, FIG. 2 shows the results of evaluation of the emission gas characteristics due to temperature rise using a SiC internal jig. For comparison of the emission gas characteristics, stainless steel material A, molybdenum (Mo) sprayed B, silicon carbide (Si
A jig C having C) on the surface and a SiO ₂ substrate D are prepared and measured by heating with a lamp heater in an actual sputtering device.

Usually, stainless steel is often used inside the chamber. Degree of vacuum reached at room temperature (2.2 × 10 ^-5 P
After evacuation to a), the stainless steel member A is gradually heated from room temperature.
When heating, the water (H ₂ O) etc. is released first and the vacuum degree temporarily deteriorates, but after a while,
Recover. However, from 250 ° C. or higher, a large amount of background H ₂ is released, and the degree of vacuum deteriorates again.

The Mo sprayed member B is similar to the stainless steel material,
First, after releasing water and the like, a large amount of background H ₂ is released from 400 ° C. or higher, and the degree of vacuum deteriorates again. The Mo sprayed member B shows a characteristic curve similar to that of the stainless steel material, but the degree of vacuum is deteriorated by a factor of 3 when releasing water or the like.

Further, since the SiC jig C and the SiO ₂ substrate D have little adsorption of moisture even when they are gradually heated from room temperature,
Unlike stainless steel, the vacuum characteristics do not change rapidly and the degree of vacuum gradually deteriorates. That is, it is estimated that the background H ₂ emission gradually increases.

In particular, the stainless material A and Mo sprayed member B
The amount of released gas is smaller than that of the above, and the released gas other than the background is not seen, and deterioration of exhaust characteristics due to H ₂ gas release is prevented.

Therefore, according to the present invention, it is possible to remarkably reduce the frequency of replacement of the stainless steel anti-adhesion plate and the internal jig in which the peeling of the adhered film has conventionally occurred. In addition, the SiC film has a strong corrosion resistance to chemicals (acid), maintains the initial surface roughness even when washed to remove the adhered film, has a small coefficient of thermal expansion, and does not deform at room temperature to 1000 ° C. Absent. Further, even when left in the atmosphere, it has the same emission gas characteristics as the SiO ₂ substrate, and is extremely lightweight as compared with the stainless steel material.

Therefore, by using the deposition preventive plate coated with SiC and the internal jig of the present invention, the cleaning work is easy and the damage to the deposition preventive plate is reduced, the exhaust characteristic is improved in the high temperature process, and the work is performed by the weight reduction. Can provide ease of sex.

Further, the present invention is not limited to the above-mentioned embodiment, but graphite was used as a base material in the embodiment, but the present invention is not limited to this, and a member having a thermal expansion coefficient similar to that of the attached film is used. The same effect can be expected with a ceramic sintered body having a small coefficient of thermal expansion. Of course, various modifications and applications are possible without departing from the scope of the invention.

[0032]

As described in detail above, according to the present invention, even a film having a strong internal stress that adheres is difficult to peel off,
It is possible to provide a lightweight anti-adhesion plate and an internal jig that emit little gas.

[Brief description of drawings]

1A is a sectional view showing a structure of an adhesion-preventing plate of a first embodiment according to the present invention, and FIG. 1B is a sectional view showing a structure of an adhesion-preventing plate of a second embodiment; FIG. 1C is a sectional view showing the structure of the deposition preventive plate of the third embodiment.

FIG. 2 is a diagram showing a characteristic of gas released from an internal jig due to temperature rise.

FIG. 3 is a diagram showing a structure of a general sputtering apparatus.

FIG. 4 is a diagram showing a peeled state of a TiN film formed on a shutter plate.

[Explanation of symbols]

1 ... Chamber, 2 ... Target, 3 ... Upper electrode, 4 ... Target presser, 5 ... Substrate, 6 ... Lower electrode, 7 ... Shutter, 8 ... Adhesion plate, 9 ... TiN film, 9a ... Crack,
9b ... Release film, 11 ... Anti-adhesion plate, 12 ... Graphite plate, 13 ... S
iC film.

Claims (2)

[Claims] 1. An apparatus for forming a thin film in a predetermined atmosphere, comprising an adhesion preventing means for preventing film formation in an undesired region other than a substrate to be processed, wherein a SiC layer having a surface roughness is exposed on the surface. An adhesion-preventing plate and an internal jig. 2. The deposition preventive plate and the internal jig according to claim 1, wherein the SiC layer has a film thickness of 100 to 1000 μm and a surface roughness of 10 to 100 μm.