JP2007081218A - Member for vacuum device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a member, to be used for a plasma treatment device (plasma cleaning device, ashing device, sputtering device and the like) in manufacturing a semiconductor or the like, in which wearing is remarkably decreased and particle generation caused by contact with plasma is also reduced. <P>SOLUTION: The present invention relates to a member for vacuum device coated, on its surface, with a corrosion-resistant glass spraying film comprised of at least Si, O, 3a base element or 2A base and Zr. Said member improves corrosion resistance for plasma and reduces particle generation. Such a corrosion-resistant member can be manufactured by spraying, to a base material, a powder mixing a silicon-nitride, silica and 3a base oxide powder and a zirconia powder. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a vacuum apparatus member used in a plasma processing apparatus (plasma cleaning apparatus, ashing apparatus, sputtering apparatus) or the like in the manufacture of semiconductors and the like, and includes inert gas, N ₂ , H ₂ , and O ₂ gas. The present invention relates to a member that consumes less plasma and generates less particles.

In a plasma processing apparatus in a manufacturing process of semiconductors and the like, cleaning of wafers and chambers, ashing, sputtering film formation, and the like are performed using plasma of an inert gas or N ₂ , H ₂ , or O ₂ gas.

  Quartz glass, ceramics such as alumina and aluminum nitride, or metals such as aluminum and stainless steel are used for the parts that come into contact with plasma, such as containers, inner walls, and components of the apparatus using such plasma.

  However, these members have a problem that they are consumed by plasma processing and cause generation of particles in the apparatus. Regarding the consumption due to the plasma treatment, alumina, aluminum nitride, and the like are less consumed than quartz glass, but yttria is further less consumed (see, for example, Patent Document 1). In addition, it has also been proposed to apply an alumina sprayed film having a specific surface state to a quartz glass member in order to prevent particles generated by peeling off a deposited film attached to the member (see, for example, Patent Document 2). Also, a thermal sprayed film that suppresses generation of particles with little wear against plasma using F or Cl-based halogen gas has been proposed (see, for example, Patent Document 3).

JP-A-10-004083 JP 2003-212598 A JP 2004-253793 A

As described above, in a process using an inert gas or plasma of N ₂ , H ₂ , or O ₂ gas in a manufacturing process of a semiconductor or the like, generation of particles resulting from consumption of a member due to plasma treatment or peeling of a deposited film, There were problems such as product contamination and yield reduction.

  In addition, as a result of examining the generation of particles by the present inventors, it has been found that in plasma processing, there are particles generated by the contact of plasma with the member even if the member is not consumed by the plasma and the deposited film is not attached.

It is an object of the present invention to provide a glassy corrosion-resistant sprayed coating that is less consumed by plasma treatment using an inert gas, N ₂ , H ₂ , or O ₂ gas, and that is less consumed by members and less particles due to contact with plasma. A vacuum device member coated on the surface is provided.

  As a result of intensive investigations in view of the above-described situation, the present inventors have formed a thermal spray film containing a glass phase on the surface of the substrate, thereby significantly reducing the consumption of the vacuum device member, and the member consumption. In addition, the inventors have found that the generation of particles due to contact with plasma is small, and have completed the present invention.

  Hereinafter, the vacuum device member of the present invention will be described in detail.

Among the present inventions, the first invention is a vacuum apparatus member exposed to plasma selected from an inert gas, N ₂ , H ₂ , and O ₂ , and a sprayed film is applied to the surface of the member. The sprayed film includes a glass phase composed of at least Si, O, and Group 3a and / or Group 2a elements.

The vacuum apparatus member according to the first aspect of the present invention is used in a plasma cleaning apparatus, an ashing apparatus, a sputtering apparatus, and the like using a plasma of a gas selected from an inert gas, N ₂ , H ₂ , and O ₂ . An inert gas is a noble gas. A sprayed film including a glass phase composed of at least Si, O and 3a group and / or 2a group element is formed on the surface of the base material for these members. The sprayed film contains a glass phase, so that there are few crystal grain boundaries, and generation of particles due to erosion of the crystal grains due to erosion of the crystal grain boundaries during cleaning and ashing by plasma is suppressed. In addition, the sprayed raw material powder constituting the thermal spray film by containing the glass phase melts in the thermal spraying process and collides with the base material, so that the splat formed is melted well and the surface of the splat is smooth so that it is easily detached. Particles are difficult to adhere, and there is little particle generation due to contact with plasma.

  Here, 3a group is Sc, Y, and a lanthanoid element. Moreover, the 2a group said here is Mg, Ca, Sr, Ba element. A material containing a 3a group element or a 2a group element has a strong bonding force between atoms, and has an effect of suppressing spattering by plasma and reducing wear of members.

  The concentration of the group 3a element in the sprayed film on the surface of the vacuum device member of the present invention is a composition range of 10% to 78% in terms of the atomic ratio of the metal element, and 20% to 88% as the concentration of Si element. Is preferred. Moreover, as a density | concentration of 2a group element in the sprayed film of the member for vacuum devices of this invention, it is preferable that the atomic ratio of Si: 2a group element is 75:25 to 15:85.

In the second invention, in the vacuum device member exposed to plasma of a gas selected from an inert gas, N ₂ , H ₂ , and O ₂ , a sprayed film is applied to the surface of the member. The vacuum spraying member is characterized in that the sprayed film contains a glass phase composed of Si, O and 3a group and / or 2a group element and N.

  The sprayed film composed of Si, O, N, and 3a and / or 2a group elements is more vitrified because it contains N, has excellent sputter resistance, has fewer crystal grain boundaries, and plasma. The generation of particles due to the dropping of the crystal grains due to the erosion at the crystal grain boundaries during cleaning and ashing due to is further suppressed. In addition, the sprayed raw material powder constituting the thermal spray film by containing the glass phase melts in the thermal spraying process and collides with the base material, so that the splat formed is melted well and the surface of the splat is smooth so that it is easily detached. Particles are difficult to adhere, and there is little particle generation due to contact with plasma.

  As the element concentration in the sprayed film on the surface of the vacuum device member of the present invention, the nitrogen concentration is preferably in the range of 0.01 to 15 wt% when a group 3a element is included. When the group 2a element is included, the O: N atomic ratio is preferably in the range of 99.9: 0.1 to 60:40.

  In the third invention, the sprayed film on the surface of the vacuum device member is a sprayed film used in the first invention and the second invention, and contains Zr. By adding Zr to a sprayed film composed of Si, O and Group 3a and / or Group 2a elements, the melting point of the sprayed powder is lowered, the deposited sprayed film becomes dense, and consumption by plasma etching is reduced. The surface of the splat becomes smoother when it touches. The element concentration in the sprayed film on the surface of the vacuum device member of the present invention is preferably 2% or more and 70% or less in terms of the atomic ratio of the metal element when the group 3a element is included. When the 2a element is included, the atomic ratio of Zr: Si is preferably in the range of 5:95 to 70:30, and the atomic ratio of the Zr + Si: 2a group element is preferably 75:25 to 20:80. .

  The material of the vacuum device member used in the present invention is not particularly limited, and examples thereof include heat-resistant glass such as quartz glass, metals such as aluminum and stainless steel, ceramics such as alumina and mullite, resins such as polyimide and polycarbonate.

  The film thickness of the sprayed film on the surface of the vacuum device member of the present invention is not limited, but is preferably 0.01 to 3 mm, particularly preferably 0.01 to 0.5 mm. If the film thickness exceeds 3 mm, the thermal spray film may be easily cracked or peeled off due to the difference in thermal expansion coefficient with the base material. On the other hand, if it is less than 0.01 mm, it may be insufficient as a protective film. is there. The film thickness can be confirmed by observing the cross section of the member with a microscope or by analyzing the composition of constituent elements using an EPMA (X-ray microanalyzer).

  The surface roughness Ra of the sprayed film on the surface of the vacuum device member of the present invention is preferably 0.01 to 10 μm, particularly preferably 8 μm or less. If the surface of the sprayed coating is rough, the protrusions formed on the surface of the sprayed coating are etched selectively, especially at the edges, or particles that easily leave are attached to the surface of the sprayed coating and come into contact with the plasma. As a result, particles are easily generated.

The member for a vacuum device of the present invention is used in a plasma cleaning device, an ashing device, a sputtering device, or the like that uses plasma of a gas selected from an inert gas, N ₂ , H ₂ , and O ₂ .

A fourth invention, the sprayed film is a vacuum apparatus member that has been subjected to a peripheral member of the platform for mounting the base or substrate mounting the substrate, an inert gas, in the N _{2, H 2,} O 2 A member for a vacuum apparatus including a portion exposed to plasma of a gas selected from the above and etched by a bias voltage.

  In a plasma cleaning device, an ashing device, or the like, there are cases where a stage on which a processing substrate is placed or a peripheral member of the stage on which the processing substrate is placed includes a portion that is exposed to plasma and etched by a bias voltage. Occurrence is seen and the present invention can reduce it. In addition, particle generation due to peeling of the deposited film can be reduced.

  According to a fifth aspect of the present invention, there is provided a vacuum device member, wherein the vacuum device member provided with the sprayed coating is a dome-shaped, cylinder-shaped, or flat-plate-shaped member that covers the processing substrate from an upper surface and / or a side surface. It is.

  In these members, generation of particles due to contact with plasma is observed, and the present invention can reduce the generation of particles, and at the same time, can also reduce generation of particles due to peeling of the deposited film.

  Next, the manufacturing method of the member for vacuum devices of this invention is demonstrated.

  The vacuum apparatus member of the present invention can be manufactured by forming a sprayed film by a spraying method such as a member surface plasma spraying method, a flame spraying method, or a high-speed flame spraying method.

  The thermal spraying raw material used in the present invention is a raw material containing Si, O and 3a group and / or 2a group element, a raw material containing Si, O, N and 3a and / or 2a group element, Si, O and 3a group and / or Or a raw material containing a group 2a element and a raw material having a composition containing a Zr element, a raw material having a composition containing Si, O, N and 3a group and / or a group 2a element and a Zr element, and preferably using a powdery raw material. .

  As such a raw material, for example, a mixture of powder granules composed of at least silica, silicon nitride and 3a group oxide and zirconia, or a powder composed of silica and at least composed of group 2a oxide and zirconia are mixed in a predetermined ratio. It can be prepared by pulverizing after producing a sintered or melted ingot. In this case, in the case of a composition containing nitrogen, it is necessary to carry out under a reducing atmosphere under pressure or normal pressure when sintering or melting. It is also possible to obtain a mixed powder comprising at least silica, silicon nitride, 2a group oxide and zirconia, and then granulating the mixed slurry by a spray drying method, and then obtaining the granulated powder by a method such as sintering the granule. . In each method described above, an acrylic binder or the like may be added as necessary.

  Although there is no limitation on the particle size of the raw material powder used for thermal spraying, the average particle size (secondary particle size) is preferably 5 to 100 μm. If the average particle size is less than 5 μm, the raw material powder itself does not have sufficient fluidity, and it may be difficult to uniformly supply the raw material into the thermal spray frame. On the other hand, if the average particle size exceeds 100 μm, the sprayed particles may not be melted uniformly, and the adhesion of the resulting sprayed film to the substrate may be likely to deteriorate.

  In the present invention, it is preferable that the temperature of the substrate surface be preheated and sprayed in advance when spraying on the surface of the vacuum device member. Preheating the substrate surface in advance is effective for preventing thermal cracking of the substrate due to heat shock and obtaining a sprayed film with high adhesion. Although the preheating temperature varies depending on the type of substrate used, for example, a range of 50 to 800 ° C. for a quartz glass substrate, 50 to 500 ° C. for a metal substrate, and 50 to 200 ° C. for a resin substrate is preferable.

  If the preheating temperature is raised too much, when creating a sprayed film containing nitrogen, nitrogen in the sprayed film is decomposed, which is not preferable. Preheating may be performed by heating the substrate with an external heater, or irradiating the substrate with a thermal spray frame without supplying raw materials. The preheating temperature can be measured with a thermocouple from the back surface of the substrate or with a non-contact radiation thermometer.

  The sprayed film used in the present invention is preferably formed by a plasma spraying method because the powder is preferably melted well during the spraying process. FIG. 1 shows a general plasma spraying apparatus. The plasma spraying apparatus melted and melted the thermal spray powder 13 using a high-temperature plasma jet of about 10,000 degrees formed by the plasma gas 12 flowing between the anode 11 and the cathode 10 being arc discharge. The sprayed powder is put on a plasma jet, accelerated, collides with the base material 15, and is instantly flattened and cooled to be deposited.

When the sprayed film on the surface of the vacuum device member of the present invention is one containing nitrogen in the sprayed film, an inert gas such as N ₂ or Ar or a reducing gas such as H ₂ is used as the spray gas. Is preferred. In the thermal spraying of a nitrogen-containing substance, if oxygen is contained in the plasma gas, it is oxidized during the thermal spraying, and the corrosion resistance is lowered by the disappearance of nitrogen from the sprayed film. Regarding the nitrogen content in the sprayed film, the surface of the sprayed film is subjected to fluorescent X-ray analysis or EPMA analysis, or the thermal conductivity of nitrogen gas generated after thermally decomposing a small amount of the sprayed film is measured. Analyze by using a nitrogen analyzer to measure. When creating a sprayed film that does not contain nitrogen, a gas such as air can be used as the sprayed gas.

  In addition to the plasma spraying method, the sprayed film of the present invention can also be manufactured by flame spraying or high-speed flame spraying as a general spraying method. In this case, when the nitrogen-containing sprayed film is produced, it can be produced under normal flame spraying conditions, but it is preferable to perform the spraying in a reducing atmosphere flame in which the fuel is excessive with respect to oxygen or the like.

  When manufacturing the sprayed film on the surface of the vacuum apparatus member of the present invention, the spraying distance, which is the distance between the tip of the spraying gun and the substrate under normal pressure, is preferably 40 to 150 mm. If the spraying distance exceeds 150 mm, the sprayed material will cool down before adhering to the substrate, and the sprayed film may not be deposited on the substrate. If the spraying distance is shorter than 40 mm, the temperature of both the substrate and the sprayed film will rise. May cause cracking of the sprayed film, and when creating a sprayed film containing nitrogen, the loss of nitrogen occurs due to the decomposition of the nitride in the sprayed powder, resulting in reduced corrosion resistance. There is.

  In the thermal spraying of the present invention, the thermal spraying power to be applied when spraying the thermal spraying frame onto the base material varies depending on the apparatus used. For example, in the case of a plasma thermal spraying apparatus as shown in FIG. 1, the thermal spraying power is set to 20 kW or more. Conditions can be exemplified.

  The surface roughness Ra of the surface of the vacuum device member used as the base of the sprayed film is preferably 1 to 15 μm. If the surface roughness Ra is less than 1 μm, the substrate and the sprayed coating may be easily peeled off, and it may be difficult to uniformly coat the corrosion-resistant glass sprayed coating on the substrate. On the other hand, if the surface roughness Ra exceeds 15 μm, it may be difficult to suppress etching by plasma. As a method of setting the surface roughness Ra of the substrate surface to 1 to 15 μm, a method of spraying a sprayed film having such a surface roughness on the substrate in advance, a method of blasting the substrate itself, or a blasting treatment and hydrofluoric acid The method etc. which perform the chemical etching by etc. collectively can be illustrated.

  The vacuum device member of the present invention is less consumed when used in a plasma processing apparatus such as a plasma processing apparatus (plasma cleaning apparatus, ashing apparatus, sputtering apparatus) in the manufacture of semiconductors, etc. Since there is little particle generation due to, there is no contamination of the product and continuous operation is possible with a high product yield.

  The present invention will be described in detail based on examples, but the present invention is not limited to these examples.

Example 1
1) Preparation of thermal spraying raw material powder When silica, zirconia, 3a group or 2a group oxide shown in Table 1 and nitrogen are included, silicon nitride is prepared to have the composition shown in Table 1, and a binder is mixed into these powders. Thereafter, a granulated powder having an average particle diameter of 50 μm was obtained by spray drying. The granulated powder was degreased at 500 ° C. for 2 hours and then sintered at 1200 ° C. for 2 hours to obtain a sintered powder having an average particle size of 50 μm.

2) Member adjustment for vacuum apparatus The outer peripheral part of the peripheral member (made of quartz glass) on which the processing substrate of the plasma cleaning apparatus is placed was blasted with alumina to make the surface roughness 6 μm.

3) Formation of corrosion-resistant sprayed film Using the substrate prepared in 1) and using the plasma spraying apparatus shown in FIG. 1 at normal pressure, nitrogen 40 SLM (Standard Litter per Minute) and hydrogen 12 SLM were passed as plasma gases. While the spraying distance was 60 mm and the spray gun was moved at a speed of 400 mm / sec, plasma was generated at a power of 30 kW, and the base material was preheated without supplying raw material powder.

  Next, the spraying raw material powder prepared in 2) was supplied at a feed rate of 7 g / min, sprayed 15 times while moving the spray gun at a speed of 400 mm / second, a pitch of 4 mm, and a spray distance of 60 mm to form a sprayed film.

  After forming the sprayed film, the member was ultrasonically cleaned with pure water in a clean room and dried in an oven.

4) Performance evaluation The vacuum device members (peripheral members on the stage on which the processing substrate is placed) obtained in 3) are mounted in the plasma cleaning device, 300 silicon wafers are sent from the load lock chamber, and Ar gas is supplied one by one. The plasma was cleaned. Further, the number of particles on the wafer (difference before and after the treatment at 0.2 μm or more) was examined every 50 sheets. After the plasma cleaning of all the wafers was completed, the thickness of the vacuum device member was measured. Table 1 shows the nitrogen content, scraping amount, and average number of particles of each vacuum device member. All of the vacuum device members were excellent because the amount of scraping was as small as 5 μm or less, the average number of particles was as small as 3 or less.

Comparative Example 1
Blasting with alumina was performed on the outer peripheral portion of the peripheral member (made of quartz glass) on which the processing substrate of the plasma cleaning apparatus is placed, and the surface roughness was set to 6 μm. This member was ultrasonically cleaned with pure water in a clean room and dried in an oven.
Next, plasma cleaning was performed in the same manner as in Example 1. After the plasma cleaning, the thickness of the vacuum device member was measured. The amount of scraping of the uncoated member for the vacuum apparatus was as large as 10 μm, the consumption was large, and the average number of particles was 10, which was larger than in the example.

Comparative Example 2
The alumina sprayed film was applied to the peripheral member of the stage on which the processing substrate of the plasma cleaning apparatus was placed in the same manner as in Example 1, and precleaning was performed in the same manner as in Example 1. After pre-cleaning, the thickness of the member was measured. The amount of scraping of the vacuum device member was relatively small at a detection limit of 5 μm or less, but the average number of particles was 8, which was larger than Example 1.

Example 2
Blasting with alumina was performed inside the cylinder member (made of quartz glass) of the ashing device, and the surface roughness was 5 μm. Further, a corrosion-resistant sprayed film was formed by the same method as in Example 1, and then ultrasonically cleaned with pure water in a clean room and dried in an oven.

  This cylinder member was mounted on an ashing device, 20 wafers were ashed, and the number of particles was examined under the same conditions as in Example 1. The number was 2 on average.

Comparative Example 3
Blasting with alumina was performed inside the cylinder member (made of quartz glass) of the ashing device, and the surface roughness was 5 μm. Then, it ultrasonically cleaned with pure water in a clean room and dried in an oven.

  This cylinder member was mounted on an ashing device, 20 wafers were ashed, and the number of particles was examined under the same conditions as in Example 1. As a result, the number was 7 on average.

Comparative Example 4
Blasting with alumina was performed inside the cylinder member (made of quartz glass) of the ashing device, and the surface roughness was 5 μm. Further, an alumina sprayed film was formed by the same method as in Example 1, and then ultrasonically cleaned with pure water in a clean room and dried in an oven.

  This cylinder member was mounted on an ashing device, 20 wafers were ashed, and the number of particles was examined under the same conditions as in Example 1. The number was 11 on average.

It is a figure which shows an example of a plasma spraying apparatus.

Explanation of symbols

10: Cathode 11: Anode 12: Plasma gas 13: Thermal spray powder (supply port)
14: Thermal spray distance 15: Base material 16: Thermal spray film 17: Power supply

Claims (5)

In a vacuum device member that is exposed to plasma of a gas selected from an inert gas, N ₂ , H ₂ , and O ₂ , a sprayed film is applied to the surface of the member, and the sprayed film is at least Si, O And a glass phase member comprising a group 3a and / or a group 2a element. The vacuum apparatus member according to claim 1, wherein N is contained in the sprayed film. The member for a vacuum apparatus according to claim 1 or 2, wherein the sprayed film contains Zr. The vacuum apparatus member to which the sprayed film is applied is a stage on which a processing substrate is placed or a peripheral member of a stage on which a processing substrate is placed, and a plasma of a gas selected from an inert gas, N ₂ , H ₂ , and O ₂ The member for a vacuum apparatus according to claim 1, wherein the member includes a portion that is exposed to the surface and etched by a bias voltage. 4. The vacuum apparatus member to which the sprayed film is applied is a dome-shaped, cylinder-shaped, or flat-plate-shaped member that covers the processing substrate from the upper surface and / or the side surface. For vacuum equipment.

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