JP2001127035A - Method of cleaning surface of process chamber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of cleaning the surface of a process chamber which can surely remove the matter having adhered to the surface of the process chamber, without doing damage to the surface of the process chamber. SOLUTION: After finish of the etching treatment to a specified number of wafers W, the anodized surface of the upper chamber part 5 in the process chamber 2 is wiped with cloth or the like wet with IPA or water. Next, a chemical vessel containing H2O2 is prepared, and H2O2 within the chemical vessel is heated to a temperature just before boiling. Then, the upper chamber 5 is put in the heated H2O2, and it is let alone for a specified time. Whereupon, reduction occurs to byproducts adhering to the anodized surface of the upper chamber part 5, and the byproducts are removed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning a surface of a process chamber for removing a substance adhered to the surface of the process chamber which has been anodized.

[0002]

2. Description of the Related Art An etching apparatus, which is one of semiconductor manufacturing apparatuses, includes, for example, a process chamber having an inner wall surface anodized (anodized), a support member provided in the process chamber and supporting a semiconductor wafer; A pump for reducing the pressure in the process chamber is provided, and plasma generating means for generating plasma in the process chamber is provided. In such an etching apparatus, when a plasma is generated in the process chamber and an etching gas is introduced into the process chamber, the etching gas is activated by plasma discharge excitation, the etching is promoted, and the reaction by-product is exhausted and removed. You.

[0003] In such an etching process, a reaction by-product generated during the etching adheres to the inner wall surface of the anodized process chamber. For this reason, when etching is performed on a plurality of semiconductor wafers, by-products accumulate on the surface of the process chamber and peel off to cause particles. Therefore, in order to prevent such a problem, conventionally, the surface of the anodized process chamber is wiped with a cloth wetted with isopropyl alcohol (IPA) or water, or rubbed with a metal polishing tool or the like. By-products adhering to the process chamber surface were removed.

[0004]

SUMMARY OF THE INVENTION However, IPA
Even if the surface of the process chamber is wiped with a wet cloth or the like, it has been difficult to sufficiently remove by-products attached to the surface of the process chamber. In addition, when a by-product adhering to the surface of the process chamber is scraped off with a rough-surfaced polishing tool or the like, the protective film formed by the anodic treatment may be scraped together.

An object of the present invention is to provide a method for cleaning the surface of a process chamber which can surely remove a substance adhered to the surface of the process chamber without damaging the surface of the process chamber.

[0006]

In order to achieve the above object, a method for cleaning the surface of a process chamber according to the present invention comprises the steps of: removing a substance adhered to the anodized surface of the process chamber from H ₂ O ₂ in a heated state; To remove.

In the present invention, the process chip
H in heated state with chamber surface _TwoO_TwoContact with
Substances that adhere to the process chamber surface
To reduce the amount of adhered substances.
You. At this time, the surface of the process chamber is shaved.
Damage to the process chamber surface.
Page is reduced.

[0008] In the cleaning method of the process chamber surfaces, preferably, H ₂ comprising the steps of: providing a container O ₂ is on, and heating the of H ₂ O ₂ in the container, of H ₂ O ₂ in the container Dipping the surface of the process chamber. In this case, the H ₂ O ₂ in the container is heated in advance, and the surface of the process chamber is immersed in the heated H ₂ O ₂ , or the surface of the process chamber is immersed in H ₂ O ₂ in the container. Then, by heating the H ₂ O ₂ , the surface of the process chamber can be brought into contact with the heated H ₂ O ₂ .

Preferably, when H ₂ O ₂ is heated, it is heated to a temperature immediately before boiling of H ₂ O ₂ . This makes it possible to effectively remove the adhered substances using H ₂ O _{2 in} a short time.

[0010] More preferably, after removing the substance adhering to the surface of the process chamber with isopropyl alcohol or water, the substance remaining on the surface of the process chamber is further removed by H ₂ O ₂ in a heated state.
As a result, the substances containing Br, Cl, Si and the like among the substances adhering to the process chamber surface are removed in advance by isopropyl alcohol or water, so that H ₂ O ₂
Can effectively remove attached substances.

After removing the substances adhering to the surface of the process chamber by H ₂ O ₂ in a heated state, it is preferable to wash the surface of the process chamber with water and to dry it.

The process chamber includes a lower chamber having a vacuum evacuation system, and an upper chamber detachably attached to an upper surface of the lower chamber and having a gas inlet, and an inner wall of the upper chamber. In the case of using an anodized surface, the upper chamber is removed from the lower chamber, and the substance attached to the inner wall surface of the upper chamber is removed by H ₂ O ₂ in a heated state.

For example, the material of the process chamber is aluminum, and Al ₂ O ₃
A film is formed.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the method for cleaning the surface of a process chamber according to the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic diagram showing a dry etching apparatus provided with a process chamber to which the cleaning method according to the present invention is applied. In FIG. 1, an etching apparatus 1 includes a process chamber 2 made of aluminum.
And a ring-shaped support member (cathode) 3 provided in the process chamber 2 and supporting an edge portion of the semiconductor wafer W to be etched on the upper surface.
The process chamber 2 includes a lower chamber section 4 and an upper chamber section 5 which is detachably attached to an upper surface of the lower chamber section 4 with bolts or the like. An exploded perspective view of such a process chamber 2 is shown in FIG.

In FIG. 2, the lower chamber portion 4 has two openings 6a and 6b on the upper surface. The support member 3 described above is provided at a position corresponding to the opening 6a in the lower chamber portion 4 so as to be vertically movable via a guide mechanism (not shown). Further, on both side surfaces of the lower chamber portion 4, a wafer entrance 7 for taking the wafer W in and out of the process chamber 2 is provided. Support member 3
Is usually at an initial position where the wafer W loaded from the wafer entrance 7 can be supported, and rises to a process position (see FIG. 1) protruding from the upper surface of the lower chamber portion 4 during the etching process. .

The opening 6 in the lower chamber 4
A turbo pump 9 is attached to a lower portion of the portion corresponding to b through a gate valve 8. The turbo pump 9 forms a part of a vacuum evacuation system for depressurizing the inside of the process chamber 2.

The upper chamber section 5 has openings 10a, 1 corresponding to the openings 6a, 6b of the lower chamber section 4 on the lower surface.
0b. In addition, at the position corresponding to the openings 10a and 10b on the upper surface of the upper chamber portion 5, the openings 1 are provided.
1a and 11b are provided. A gas inlet 12 for introducing an etching gas and a dry cleaning gas into the process chamber 2 is provided on a side surface of the upper chamber portion 5. In addition, a plurality of handles 13 are provided at an edge of the upper chamber section 5, so that a wet cleaning operation described later can be easily performed.
The inner wall surface of the upper chamber portion 5 forms an anodized surface on which an Al ₂ O ₃ film as a protective film is applied, that is, anodized (anodized).

Returning to FIG. 1, a ceramic dome 14 is provided above the upper chamber 5 so as to cover the opening 11a. The dome 14 is provided with a coil 15, and the coil 15 is connected to an RF generator 17 via a matching network 16 to generate plasma in the process chamber 2. Further, an RF generator 19 for bias is connected to the support member 3 via a matching network 18 so as to enhance the transfer of the plasma species generated by the RF generator 17 to the surface of the wafer W. The opening 11b of the upper chamber 5 is closed by a cover member (not shown).

A method of performing the Si etching process on the surface of the wafer W using the etching apparatus 1 configured as described above and the cleaning process of the process chamber 2 thereafter will be described with reference to the flowchart of FIG.

First, while the gate valve 8 is opened and the inside of the process chamber 2 is evacuated to a reduced pressure by the turbo pump 9, the wafer W is loaded from the wafer entrance 7 by the transfer robot (not shown) and placed on the support member 3. I do. Subsequently, the supporting member 3 is raised from the initial position to the process position (see FIG. 1) by a driving unit (not shown). And
A high frequency is applied to the coil 15 by the RF generator 17 to generate plasma in the process chamber 2. Subsequently, for example, a Cl ₂ gas or an HBr gas is used as an etching gas through the gas inlet 12 through the process chamber 2.
When introduced into the etching gas, the etching gas is activated by the plasma discharge excitation to promote the etching of Si,
Reaction by-products such as ₂ and AlF ₃ are exhausted and removed. Then, the support member 3 is lowered from the process position to the initial position by the driving means (not shown), and the wafer W is carried out of the process chamber 2 from the wafer entrance 7 by the transfer robot (not shown) (step 101). .

Such an etching process is performed on a predetermined number (for example, 25) of wafers W (step 10).
2) Thereafter, in order to remove by-products such as SiO ₂ adhered to the inner wall surface of the upper chamber portion 5, that is, the anodized surface during the etching, the following dry cleaning in the process chamber 2 is performed (step 103). .

First, CF is used as a dry cleaning gas.
_A fluorine-based gas such as ₄ gas, SF ₆ gas, NF ₃ gas or the like is introduced into the process chamber 2 from the gas inlet 12, and a high frequency is applied to the coil 15 by the RF generator 17 to generate plasma in the process chamber 2. generate. Then, the fluorine-based gas is activated, by-products adhering to the anodized surface of the upper chamber portion 5 are decomposed and removed by the fluorine radicals F ^*, and are exhausted from the process chamber 2.

However, it is actually difficult to completely remove by-products adhering to the anodized surface of the upper chamber 5 only by such dry cleaning. Therefore, a predetermined number (for example, 1000) of wafers W are further etched (step 104).
Thereafter, wet cleaning of the upper chamber section 5 is performed as described below.

First, with the gate valve 8 closed and the rotation of the turbopump 9 stopped, the dome 14 and a lid member (not shown) are removed from the upper chamber section 5 and the upper chamber section 5 is removed. (Step 105).

Then, isopropyl alcohol (IP
A) or wipe the anodized surface of the upper chamber part 5 with a cloth moistened with water (step 106). As a result, of the by-products adhering to the anodized surface, substances that include deposits that can be easily removed by IPA or the like, for example, substances containing Br, Cl, Si, etc. are removed. Note that such cleaning with IPA or water may be performed by spraying IPA or water onto the anodized surface of the upper chamber 5.

Next, a chemical tank (container) containing hydrogen peroxide (H ₂ O ₂ ) is prepared (step 107), and H ₂ O ₂ in the chemical tank is heated (step 108). At this time,
Preferably, H ₂ O ₂ is heated to a temperature immediately before boiling (about 80 ° C.). Then, the upper chamber section 5 is put into the heated H ₂ O ₂ and left for a predetermined time (for example, about 30 minutes to 1 hour). Then, a reducing action occurs on the by-products such as SiO ₂ adhered to the anodized surface of the upper chamber portion 5, and the by-products are sufficiently removed (step 109). At this time, the anodized surface of the upper chamber section 5 is immersed in H ₂ O ₂ heated to a temperature immediately before boiling, so that by-products attached to the anodized surface can be efficiently removed in a relatively short time.

[0028] Here, was to put the upper chamber portion 5 in the heated H ₂ O _2, was placed the upper chamber portion 5 in the H ₂ O _2, the H ₂ O ₂ You may make it heat. In addition, H ₂ O ₂ is used because H ₂ O ₂
Is considered to have erosion resistance to aluminum which is a material of the upper chamber portion 5.

Next, as a post-treatment, the upper chamber 5 is taken out of H ₂ O ₂ , the anodized surface of the upper chamber 5 is washed at least once with water, and dried (step 110). As a result, the anodized surface of the upper chamber section 5 is regenerated to a surface having substantially the same performance and appearance as before the etching process. afterwards,
The upper chamber part 5 is assembled on the upper surface part of the lower chamber part 4, and the dome 14 and a lid member (not shown) are attached to the upper chamber part 5 (step 111).

As described above, in the present embodiment, by dipping the anodized surface of the upper chamber 5 in H ₂ O ₂ in a heated state, by-products attached to the anodized surface are removed by a reducing action. As a result, by-products can be sufficiently removed without cutting the anodized surface. Thereby, particles adhering to the wafer W supported by the support member 3 are reduced, and productivity is improved. In addition, since the anodized surface does not need to be shaved, the reduction amount of the protective oxide film is suppressed, and damage to the anodized surface is reduced. Further, since an anodized surface substantially equal to that before the etching process is obtained, the period for performing the wet cleaning can be lengthened.

Although the preferred embodiment of the present invention has been described above, it is needless to say that the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the anodized surface of the upper chamber 5 is immersed in H ₂ O ₂ in a heated state in the container. H ₂ O ₂ may be sprayed.

Further, the process chamber 2 of the above embodiment is made of aluminum and has an Al ₂ O ₃ film formed on the inner wall surface of the upper chamber portion 5. Also applicable to process chambers. The process chamber 2 includes a separable lower chamber part 4 and an upper chamber part 5 and is formed by anodic oxidation on the surface of the upper chamber part 5. However, the present invention provides an integrated process chamber. Can also be applied. Further, the above process chamber is mounted on a dry etching apparatus, but the present invention is also applicable to a process chamber mounted on another semiconductor manufacturing apparatus.

In the above embodiment, hydrogen peroxide (H ₂ O ₂ ) is used as a chemical solution for wet cleaning. However, dilute hydrofluoric acid may be used instead of H ₂ O ₂ .

[0034]

According to the present invention, the substance adhering to the anodized process chamber surface is removed by H ₂ O ₂ in a heated state, so that the process chamber surface is not damaged. In addition, the adhered substances can be reliably removed, thereby improving the productivity.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a dry etching apparatus including a process chamber to which a cleaning method according to the present invention is applied.

FIG. 2 is an exploded perspective view of the process chamber shown in FIG.

3 is a flowchart showing a method for performing a wafer etching process using the etching apparatus shown in FIG. 1 and a subsequent process chamber cleaning process.

[Explanation of symbols]

2 ... Process chamber, 4 ... Lower chamber, 5 ...
Upper chamber part, 8 ... Gate valve (evacuation system),
9: turbo pump (vacuum exhaust system), 12: gas inlet.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Daisuke Tajima 14-3 Shinsen, Narita-shi, Chiba Applied Materials Japan Co., Ltd. (72) Inventor Kenya Ogata 14-3 Shinizumi, Narita-shi, Chiba Nogedaira Industrial Park Applied Materials Japan Co., Ltd. F-term (reference) 5F004 AA15 BB29 DA01 DA17 DA18 FA08

Claims (8)

[Claims] 1. A method for cleaning a surface of a process chamber in which a substance adhered to the surface of the process chamber that has been anodized is removed by H ₂ O ₂ in a heated state. Pickles a step wherein providing a container containing the H ₂ O _2, and heating the of H ₂ O ₂ in the vessel, the process chamber surface of H ₂ O ₂ in the container 2. The method according to claim 1, further comprising the steps of: 3. When heating the H ₂ O ₂ , the H ₂ O _2
3. The method for cleaning a surface of a process chamber according to claim 1, wherein the heating is performed to a temperature immediately before the boiling of O2. 4. The method according to claim 1, wherein after removing a substance adhering to the surface of the process chamber with isopropyl alcohol or water, a substance remaining on the surface of the process chamber is further removed by the heated H ₂ O _2.
The method for cleaning a surface of a process chamber according to any one of claims 1 to 3. 5. After removing a substance attached to the process chamber surface by the heated H ₂ O ₂ ,
The method for cleaning the surface of the process chamber according to claim 1, wherein the surface of the process chamber is washed with water and dried. 6. The upper chamber section as the process chamber, comprising: a lower chamber section having a vacuum exhaust system; and an upper chamber section detachably attached to an upper surface of the lower chamber section and having a gas inlet. The material whose inner wall surface is anodized is used, and the substance adhered to the inner wall surface of the upper chamber portion is removed by the H ₂ O _{2 in} the heated state. Cleaning method for process chamber surface. 7. The process chamber is made of aluminum, and the surface of the process chamber is made of Al _2.
The method for cleaning a surface of a process chamber according to claim 1, wherein an O ₃ film is formed. 8. The method according to claim 1, wherein the process chamber is provided in a dry etching apparatus.