JP3408530B2 - Member for semiconductor manufacturing apparatus and method for manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus such as a wafer heat treatment apparatus, an oxidation-diffusion processing apparatus and a CVD.
Device, cylinder (cylinder), gas supply pipe,
The members used as constituent materials of exhaust systems (including pumps) of reactor devices, related devices such as exhaust gas treatment devices, and the manufacturing method thereof are particularly excellent in corrosion resistance to halogen compounds and at the same time resistant to treatment under high vacuum. The present invention relates to a method for manufacturing a member for a semiconductor manufacturing apparatus, which is formed by forming a complex oxide film having excellent metal releasing property.

[0002]

2. Description of the Related Art In many cases, semiconductor devices are manufactured by forming wirings and coatings as insulating layers on a silicon wafer. As an apparatus for manufacturing the semiconductor, oxidation-
There are a diffusion device, a CVD device, and the like. The oxidation-diffusion device introduces water vapor or oxygen and HCl generated by mixing hydrogen and oxygen into a reaction vessel to form an oxide film on a silicon wafer, and an oxide film forming process such as phosphorus and boron. This is a device for diffusing the impurities. The CVD apparatus is an apparatus that introduces several kinds of reactive gases into a processing furnace and forms a desired film on a silicon wafer by a chemical reaction in a temperature range of 300 to 1000 ° C. These devices use, for example, inorganic materials such as quartz and metallic materials as reaction vessel constituent members for processing silicon wafers, and tend to exclude the use of metals, but all of them are non-metallic inorganic materials. It is difficult to use it as a material and it is also disadvantageous in terms of cost.

Among the constituent members of the reaction vessel, the material of the portion in contact with the atmospheric gas is conventionally stainless steel (SUS).
316L) and other metal materials having a chromium passivation film formed on their surfaces have been used. For example, by chemically changing chromium oxide, that is, chromium (VI) oxide (CrO ₃ ), on the surface of a stainless steel substrate, chromium (I
II) There is a technique for forming a hard coating composed of fine particles of oxide (Cr ₂ O ₃ ), which are disclosed in JP-A-59-9171, JP-A-61-52374, and JP-A-63-12668.
The disclosed techniques such as Japanese Patent Laid-Open No. 2 and Japanese Patent Laid-Open No. 63-317680 are known. However, the chromium oxide-based passivation films disclosed in these publications do not always have sufficient characteristics for the corrosion resistance of the substrate. The reason is,
This is because the substrate material (stainless steel) component of these members adheres to the silicon wafer and causes metal contamination depending on the conditions such as the processing temperature of the film forming process. In particular, when flowing a reducing gas such as hydrogen or ammonia, when flowing a chloride-based corrosive gas, or when cleaning with a halogen-based compound such as chlorine trifluoride gas, It has been confirmed that the contamination by the matrix metal material increases.

[0004]

By the way, stainless steel is known as a metal material having excellent corrosion resistance, and its surface is in contact with the atmosphere to prevent the formation of chromium oxide (Cr ₂ O ₃ ). It forms a dynamic film. This passivation film is originally thin, and is easily destroyed by contact with erosion due to particle collision or acid solution, but it has the property of regenerating the passivation film by self-repairing action. Is. However, the chemical reaction for the regeneration requires a long time kinetically.
In particular, some of the members that make up the semiconductor manufacturing equipment are exposed to the atmosphere, the low-oxygen depressurized atmosphere, and the reactive gas alternately in a short time. There was a problem that the effect could not be obtained.

An object of the present invention is to propose a technique for obtaining a member for a semiconductor manufacturing apparatus which is excellent in corrosion resistance and metal contamination resistance. Another object of the present invention is to propose a composite oxide film-coated member having excellent corrosion resistance against various corrosive gases and halogen-based compounds, and metal contamination resistance against treatment under high vacuum.

[0006]

Means for Solving the Problems As a result of earnest research to achieve the above object, the inventors found that when a surface of a metal material base material was coated with a chemically stable composite oxide film, the base metal atom The present invention has been developed to find that it is possible to suppress the release of hydrogen and obtain effective corrosion resistance even under a strong corrosive environment.

Namely, the present invention is, on the surface of the steel substrate, a silicon oxide - aluminum oxide - formed by coating a composite oxide film comprising chromium oxide and below sintering aid, is a member for semiconductor manufacturing equipment .

Further, the present invention is the surface of the steel substrate, a silicon oxide, a slurry containing aluminum oxide and the following sintering aid to form a chemical densified coating by calcining After form the, then, A chromic acid aqueous solution containing a sintering aid is applied to the surface of the chemically densified film, sprayed or immersed in the aqueous solution, and then baked at 250 ° C to 750 ° C to give silicon oxide-aluminum oxide-chromium oxide and A method for manufacturing a member for a semiconductor manufacturing apparatus, which comprises forming a composite oxide film made of a sintering aid.

In the present invention, the composite oxide film is a chemical densification film composed of silicon oxide, aluminum oxide and a sintering aid, and the inside surface of the film is filled with the chemical densification film at the same time. The composite oxide film is formed by a layer of amorphous chromium oxide fine particles covering the film, and the composite oxide film is a chemically densified film obtained by applying a slurry containing silicon oxide, aluminum oxide and a sintering aid, and firing. An aqueous solution containing chromic acid and a sintering aid is coated on the above and baked at a temperature of 250 ° C to 750 ° C, so that chromium oxide and the sintering aid are present in the voids in the base material and on the surface of the base material. It is a preferred embodiment that the amorphous inorganic compound composite particles are formed by depositing. Na
In the present invention, the sintering aid is borated.
Compound, silicate compound and phosphate compound
At least one of:
A material made of an inorganic substance is used.

Next, the present invention also provides a semiconductor manufacturing apparatus characterized in that a precipitation layer of fine particles of fired amorphous inorganic substance comprising chromium oxide and a sintering aid is provided on the surface of a steel base material. I propose a member for use.

Furthermore, the present invention provides that the surface of a steel substrate is
Oxidation is carried out by applying a chromic acid aqueous solution containing a sintering aid, spraying or immersing it in the chromic acid aqueous solution to form a chromic acid layer, and then firing at a temperature of 250 ° C to 750 ° C. A method for manufacturing a member for a semiconductor manufacturing apparatus, which comprises forming a precipitation layer of fine particles of an amorphous inorganic material composed of chromium and a sintering aid is proposed.

In the present invention, the sintering aid is
A material comprising at least one selected from a borate compound, a silicate compound and a phosphate compound and capable of forming an amorphous inorganic substance by sintering is used .

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The constitution of a member for semiconductor manufacturing equipment, which is excellent in high corrosion resistance and low metal emission, of the present invention, in particular, a composite oxide film coated on the surface of a steel base material will be specifically described below.

A first embodiment of the present invention, the surface of the stainless steel used as a base material (SUS316L), silicon oxide (SiO ₂₎ - aluminum oxide (Al ₂ O ₃₎ - chromium oxide (Cr ₂ O ₃₎ It is a member formed by coating a composite oxide film having a composition of and a sintering aid, and is manufactured through the steps shown in FIG.

[0015] The member for a semiconductor manufacturing apparatus is according to the embodiment, degreasing and blasting roughened surface of the treated stainless steel substrate subjected to such pretreatment (spraying etc. of the alumina particles), SiO ₂ and Al _A primer slurry containing ₂ O ₃ was applied, heated to 450 ° C. at a heating rate of 500 ° C./h, held for 1 hour, and then baked at a cooling rate of 200 ° C./h. By this treatment, a chemically densified film is formed on the surface of the base material. Then, a mixed solution of a sintering aid-containing aqueous solution and a chromic acid aqueous solution, which produces an amorphous inorganic substance by being subjected to a firing treatment, is applied onto the chemically densified film, sprayed, or immersed in the aqueous solution. By doing so, after forming a film of the above components, baking is performed under the same baking conditions as above to form a complex oxide film that can be adapted to the present invention.

As an example of the sintering aid-containing aqueous solution which produces an amorphous inorganic substance by firing, an aqueous solution containing a borate compound, a silicate compound and a phosphate compound is suitable,
Those that produce borate glass, silicate glass, phosphate glass, etc. when fired are used. Further, it is preferable that the above-mentioned coating and impregnation of the mixed aqueous solution and the firing are repeated plural times.

According to the experiments conducted by the inventors, the preferable firing
Examples of conditions include a chromic acid-borate compound aqueous solution and
Heating temperature when applying acid mixture of romic acid solution
550 ℃ ~ 750 ℃, chromic acid aqueous solution-phosphate compound water
What is the heating temperature when the solution mixture is applied?
Heat at a temperature of 250 ℃ to 550 ℃ for 0.5 to 2 hours. this
When such a treatment is performed, the water contained in the aqueous solution evaporates.
And volatilize, and fine particles of chromium oxide as heating residue
An amorphous layer containing a child is formed in a thickness of about 1 to 3 μm. This black
The fine particles of aluminum oxide are chemically densified skin that is the primer layer.
Film, ie SiO ₂-Al₂O₃And sintering aid
Deposition in voids such as pores and cracks in the chemically densified film formed
It is discharged and filled (impregnated), and the chemical densification is performed.
It was confirmed that it formed so as to cover the surface of the film. You
That is, chromic acid is passed through an intermediate to Cr.₂O₃(Oxidized black
Borate compounds and silicate compounds that are present at the same time.
Substance and the aqueous solution of phosphate compound each release water
It becomes a crystalline inorganic substance.

The chemical densification film produced from each of the above aqueous solutions and the complex oxide film composed of a layer of amorphous chromium oxide fine particles are entirely SiO ₂ --Al ₂ O ₃ --Cr ₂ O ₃ -based oxide materials. Since it is composed of, it is extremely hard and has excellent wear resistance. Moreover, any one of a phosphate compound, a borate compound, and a silicate compound, which is a sintering aid, is contained, but all of them are amorphous and at least a part of which is glassy.
It also deposits and penetrates (impregnates) into voids such as pores and cracks in the chemically densified film, and fills these voids to seal them. The thickness of such a composite oxide film is preferably about 40 μm to 120 μm.

The sintering aid has a function of improving the adhesion between the particles forming the film. That is, an amorphous substance formed by firing a borate compound, a silicate compound, or a phosphate compound strengthens the bond between the Cr ₂ O ₃ fine particles in which the slurry containing chromic acid is deposited, and at the same time, increases the chemical density. It is considered that cracks in the chemical film are also strengthened by sealing. It should be noted that these components have a large affinity with oxygen and are thermodynamically stable from room temperature to a temperature range of 750 ° C. Further, since the complex oxide film is formed by heating and firing from the above-mentioned various slurries or starting materials in the form of an aqueous solution, the surface is smooth, the specific surface area is small, and the porosity is small and the film structure is dense. Can be The semiconductor manufacturing apparatus such as the oxidation-diffusion apparatus and the CVD apparatus coated with the above complex oxide film or the members for the related apparatus are often washed with a hydrofluoric acid aqueous solution during the maintenance of the apparatus. With respect to those coated with, the chemical stability to hydrofluoric acid and the environmental barrier property can prevent entry into the complex oxide film such as an aqueous solution of hydrofluoric acid for cleaning.

Table 1 exemplifies conditions for forming a complex oxide film on the surface of a steel base material under the conditions according to the present invention.

[0021]

[Table 1]

Further, FIG. 2 shows an example of a sectional structure of a portion coated with the complex oxide film according to the present invention. Here, in the figure, c is a complex oxide film, 1 is a stainless steel base material, 2 is a chemical densification film, 3 is a chromium oxide filled in the pores and cracks in the complex oxide film c-non- Crystalline sintering aid inorganic composite fine particles, 4 indicates a layer of chromium oxide-amorphous sintering aid inorganic material fine particles covering the surface of the composite oxide film. As is clear from this cross-sectional structure diagram, the layer of the chromium oxide-amorphous inorganic substance fine particles is in a state of being completely filled even in the cracks of the complex oxide film of the fine particles, It also has extremely high environmental barrier properties.

The second embodiment of the present invention is the above-mentioned SiO 2.
Method for forming a complex oxide film composed of _2- Al ₂ O ₃ -Cr ₂ O ₃ and a sintering aid on the surface of a base material (first embodiment)
Instead of the above, the following method is used to form an inorganic substance film. That is, in this embodiment, a chromic acid aqueous solution containing a sintering aid is applied to the surface of a stainless steel substrate, sprayed, or immersed in the chromic acid aqueous solution to form a chromic acid layer. Then, by baking at a temperature of 250 ℃ ~ 750 ℃, to form a precipitation layer of amorphous inorganic material fine particles consisting of chromium oxide and a sintering aid, so-called, on the stainless steel substrate A method for obtaining a member for a semiconductor manufacturing apparatus, characterized in that it has, on its surface, a deposited layer of fine particles of an amorphous inorganic substance which is composed of chromium oxide and a sintering aid.

In the case of the method of directly providing the precipitation layer of the fine particles of the amorphous inorganic material such as the fine particles of chromium oxide on the surface of the substrate as in the second embodiment, the composite of the first embodiment is used. Compared to forming an oxide film, it is possible to make a thin film, simplifying the construction method, shortening the manufacturing period,
A reduction in manufacturing cost can be realized. Moreover, the deposited layer thus obtained is sufficient not only for improving the thermal shock resistance but also for realizing the intended purpose of improving the corrosion resistance and the metal contamination resistance.

[0025]

EXAMPLES Example 1 In this example, a semiconductor manufacturing apparatus (CVD apparatus) including a member in which a complex oxide film obtained by the treatment according to the present invention was applied to a gas-contacting portion was used. A silicon wafer was heat-treated, and the metal contamination on the silicon wafer was investigated. (1) Complex oxide film of Example of the present invention: Base material (SUS316
L: an outer diameter of 300.0 mm x thickness of 0.9 mm) is coated on the inner surface with a slurry containing silicon oxide-aluminum oxide and phosphoric acid, and heated and baked to form a chemically densified film, which is then chemically densified. The coated member was immersed in an aqueous solution containing chromic acid and phosphoric acid as main components, pulled up, and then heat-treated at 450 ° C. for 1 hour, and this was repeated 6 times to form a composite oxide film (80 μm). I used one. (2) As the material of the comparative example, an untreated SUS316L steel base material was used.

Metal contamination amount evaluation test result: This test is shown in FIG.
The amount of metal contamination on the silicon wafer can be
It was measured. The results are summarized in Table 2. Table 2
As shown in Fig. 4, the untreated SUS316L steel material of the comparative example is used.
The amount of metal contamination on the silicon wafer was Fe: 3.9 × 1
0¹²atm / cm², Cu: 3.1 x 10¹²atm / cm²Met. this
On the other hand, the base coated with the composite oxide film conforming to the present invention
In material, Fe: 3.1 × 10⁹ atm / cm², Cu: 7.8 × 10⁹atm / cm
²Was reduced to.

[0027]

[Table 2]

Example 2 In this example, it is assumed that the substrate with a composite oxide film obtained by the treatment according to the present invention is washed with an aqueous acid solution, and the substrate is treated with 10% hydrochloric acid.
After soaking for 24 hours, the acid solution corrosion resistance was tested from the mass change before and after the immersion. In addition, untreated SUS31 which is a comparative example
As for 6L steel, since the mass loss due to melting was significant, the immersion time was set to 1 hour. The results of this test are shown in Table 3. As shown in Table 3, the mass change of the member with the composite oxide film according to the present invention was comparable to that of the quartz material, and it was revealed that the member exhibits excellent corrosion resistance.

[0029]

[Table 3]

Example 3: SUS316L same as Example 1
On the surface of the stainless steel base material, a chromic acid-based aqueous solution containing a sintering aid such as a phosphoric acid chloride was applied, and the base material protective property of the film of the fired amorphous inorganic material was investigated. The test is
It was completely immersed in a 10% HCl aqueous solution at 20 ° C., and the appearance change before and after the test, the weight change, and the color change of the hydrochloric acid solution were examined. For comparison, the same test was performed on the roughened SUS316L steel and the SUS316L steel that was rough-baked after roughening, and the results are shown in Table 4.

As is clear from the description in Table 4, in the examples of the present invention, there was a mass loss of about 176 mg, which is considered to have caused a part of the film to melt. However, in contrast, in the comparative example,
Corrosion progressed over the entire surface of the base material, and a mass loss of more than 200 mg was observed in each case. Therefore, it was found that even when a film of an amorphous inorganic substance mainly containing chromium oxide was formed on the surface of the base material, the desired effect was considered to be obtained.

[0032]

[Table 4]

[0033]

As described above, according to the present invention, by using a member coated with a complex oxide film peculiar to the present invention as a constituent member of a semiconductor manufacturing apparatus, metal emission from the member surface The amount can be significantly reduced and the metal contamination on the silicon wafer can be significantly reduced. Further, the member for the apparatus can be washed with an aqueous acid solution, and the cleaning maintainability of the apparatus can be improved. Further, since the member conventionally made of the quartz member can be converted into the member with the complex oxide film of the present invention, the cost can be reduced and the operation and maintenance can be facilitated, and the semiconductor manufacturing apparatus and its related apparatus can be manufactured. It is expected that the field of application of the present invention will be expanded for use members.

[Brief description of drawings]

FIG. 1 is a process drawing for forming a complex oxide film or the like on the surface of a steel base material.

FIG. 2 is a partial cross-sectional view of a member in which a surface of a steel base material is coated with a complex oxide film or the like.

FIG. 3 is a schematic diagram of a metal contamination amount evaluation tester.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI H01L 21/68 H01L 21/68 N (72) Inventor Hiroshi Sakurai 5-3-6 Akasaka, Minato-ku, Tokyo TBS Broadcasting Center Tokyo Electron Stock company (72) Inventor Kazuhide Hasebe 5-3-6 Akasaka, Minato-ku, Tokyo TBS Broadcast Center Tokyo Electron Stock company (72) Inventor Mitsuhiro Okada 5-3-6 Akasaka, Minato-ku, Tokyo TBS Broadcasting Center Tokyo Electron Stock Company (72) Inventor Atsushi Endo 5-3-6 Akasaka, Minato-ku, Tokyo TBS Broadcasting Center Tokyo Electron Stock Company (72) Inventor Tokuyuki Onodera 5-chome Akasaka, Minato-ku, Tokyo No. 3-6 TBS Broadcasting Center Tokyo Electron Stock Company (72) Inventor Jun Ogawa 5-3-6 Akasaka, Minato-ku, Kyoto TBS Broadcasting Center Tokyo Electron Stock Company (72) Inventor Kazumi Tani 2-3-5 (72) Kamiodai, Nishinomiya-shi, Hyogo Inventor Ikino Miyajima Kobe, Hyogo 3-5-11 Nippori-dori, Chuo-ku, Yokohama (72) Inventor Takema Teratani 4-12-19 Uozakiminami-cho, Higashinada-ku, Kobe-shi, Hyogo Prefecture (72) Tatsuya Hamaguchi 4-chome, Higashihongo, Midori-ku, Yokohama-shi, Kanagawa No. 13 12-6-102 (56) Reference JP-A-4-354327 (JP, A) JP-A-63-317680 (JP, A) JP-A-2000-77551 (JP, A) JP-A-2000-332091 (JP, A) (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01L 21/31 C23C 18/12 C23C 24/08 C23C 28/04 H01L 21/205 H01L 21/68

Claims (6)

(57) [Claims] 1. A silicon oxide-aluminum oxide-chromium oxide, a borate compound, and a silicate compound are formed on the surface of a steel base material.
At least one selected from the group consisting of compounds and phosphate compounds
One of which produces an amorphous inorganic material by sintering
A member for semiconductor manufacturing equipment, which is coated with a complex oxide film composed of a sintering aid which is a material . 2. The composite oxide film comprises a chemically densified film composed of silicon oxide, aluminum oxide and a sintering aid, and amorphous chromium that fills the voids in the film and simultaneously covers the surface of the film. The member for a semiconductor manufacturing apparatus according to claim 1, wherein the member is formed of a layer of oxide fine particles. 3. The complex oxide film is obtained by applying a slurry containing silicon oxide, aluminum oxide, and a sintering aid, and firing the chemically densified film, and then adding chromic acid and a sintering aid. Amorphous inorganic composite fine particles composed of chromium oxide and a sintering aid are deposited in the voids in the base material and on the surface of the base material by depositing an aqueous solution containing the same and firing at a temperature of 250 ° C to 750 ° C. The member for a semiconductor manufacturing apparatus according to claim 1 or 2, which is formed by the following method. 4. Silicon oxide, aluminum oxide, a borate compound, a silicate compound and a phosphorus are formed on the surface of a steel base material.
Sintering of at least one selected from acid salt compounds
A slurry containing a sintering aid, which is a material that produces an amorphous inorganic substance by coating, is formed and then fired to form a chemically densified film. On the surface, apply a chromic acid aqueous solution containing a sintering aid,
After spraying or immersing in the aqueous solution, 250 ℃ ~ 750 ℃
By firing at, silicon oxide-aluminum oxide-
A method for manufacturing a member for a semiconductor manufacturing apparatus, which comprises forming a composite oxide film composed of chromium oxide and a sintering aid. 5. Chromium oxide and boric acid are formed on the surface of a steel base material.
Among salt compounds, silicate compounds and phosphate compounds
Consisting of at least one selected from
A member for a semiconductor manufacturing apparatus, which has a deposited layer of fine particles of a fired amorphous inorganic substance, which is composed of a sintering aid which is a material for producing an amorphous inorganic substance. 6. A borate compound and a silica are formed on the surface of a steel substrate.
Small N salt compound Oyobiri selected from among acid salt compound
It consists of at least one kind and is amorphous by sintering
A chromic acid aqueous solution containing a sintering aid, which is a material that produces a porous inorganic substance, is applied, sprayed, or immersed in the chromic acid aqueous solution to form a chromic acid layer, and then 250 ° C to
A method for manufacturing a member for a semiconductor manufacturing apparatus, which comprises forming a precipitation layer of fine particles of an amorphous inorganic material composed of chromium oxide and a sintering aid by firing at a temperature of 750 ° C.