JPH11130473A - Quartz glass member for semiconductor production device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve light-transmitting property and corrosion resistance against a corrosive gas for quartz by forming a linear or stripe energizing heat- generating metal layer having electrodes on both ends and an alumina protective film on a quartz glass substrate. SOLUTION: A linear or stripe energizing heat generating metal layer 2 having 0.3 to 3 mm width of the line or stripe and 0.1 to 10 μm thickness and having electrodes on both ends is formed on the surface 1a of a quartz glass substrate 1 which faces the inside of a chamber when the glass substrate is attached to a semiconductor producing device. The metal layer 2 is formed in such arrangement and density that the substrate is kept seen through. The quartz glass substrate with the energizing heat-generating metal layer 2 formed is disposed in a sputtering film-forming chamber. The substrate is subjected to sputtering by using a high purity alumina of >=99% purity as a target in a plasma produced by high frequency discharge in an atmosphere of an oxygen- contg. argon gas mixed with 0.05 to 10 vol.% oxygen gas under 0.05 to 10 Pa pressure at <=400 deg.C. Thus, an alumina protective film of 1 to 50 μm thickness is formed on the surface of the quartz glass substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a quartz glass member for a semiconductor manufacturing apparatus, and more particularly, to a semiconductor manufacturing apparatus excellent in corrosion resistance against activated corrosive gas such as fluorine-based gas and transmissivity. The present invention relates to a quartz glass member for use.

[0002]

2. Description of the Related Art Quartz glass is often used as a member used in a device used in a semiconductor manufacturing process where heat resistance, thermal shock resistance, insulation, etc. are required in addition to translucency. Have been. In addition, since most of the semiconductor manufacturing equipment is a closed system, a viewing window for internal observation or the like is often provided, and as such a window material, quartz glass is often used because of its particularly excellent translucency. Have been.

On the other hand, various reaction gases and etching gases are used in a semiconductor manufacturing apparatus. In particular, in a dry etching apparatus and a plasma CVD apparatus, CF ₄ and NF are often used.
₃ , fluorine-based gases such as SF ₆ and ClF ₃ are used. In these devices, for example, a few percent
Are mixed, and a high-frequency electric field is applied under the flow of the mixture to generate plasma. The fluorine-based gas dissociates in the plasma to generate active chemical species such as fluorine radicals, which are present in the Si or SiO
Reacts with ₂ to form volatile SiF ₄ . Conventionally, also in such an apparatus, quartz glass is used as a window material used for, for example, a viewing window.

[0004]

Incidentally, since the quartz glass has low corrosion resistance to fluorine-based plasma, its surface is eroded and fogged due to long-term use,
Inconveniences such as a decrease in transparency and the inability to fulfill its function, and the occurrence of local etching to form a hole have often been encountered in the past. Recently, as semiconductor circuits have been further miniaturized, a fluorine-based gas having a relatively large molecular weight, such as C ₄ F ₈ , has been used as a reactive gas for dry etching.
However, such fluorocarbon-based gases, when decomposed by plasma, generate polymerizable fragments that recombine and polymerize. Then, it becomes a resinous fluorocarbon polymer, and is deposited and deposited inside the apparatus. When a large amount of these deposits adhere to the surface of a quartz glass member such as a viewing window, a new problem arises in that the light-transmitting property is significantly reduced and the function is not fulfilled. Therefore, it is strongly desired to have a quartz glass member for a semiconductor manufacturing apparatus which has sufficient corrosion resistance to active species such as fluorine-based plasma and does not cause deposition of decomposition products such as the fluorocarbon polymer. I was

The inventors of the present invention have conducted intensive studies on quartz glass members used as window members and the like of semiconductor manufacturing equipment in order to solve the above-mentioned technical problems. As a result, the quartz glass members were heated electrically to maintain a high temperature. Thereby, it is possible to avoid the deposition of the deposit such as the fluorocarbon polymer, and by covering and protecting the surface of the quartz glass directly in contact with the inside of the device with an alumina protective film, the active species such as the fluorine-based plasma can be prevented. It has been found that they have sufficient corrosion resistance, and that even if they are used for a long time, the surface is not eroded and clouding does not occur, and that the transparency can be maintained. Based on this finding, the present invention has been completed. Therefore, an object of the present invention is to provide excellent corrosion resistance to active species such as fluorine-based plasma, and to prevent deposition of a deposit such as a fluorocarbon polymer, and to maintain sufficient translucency even when used for a long time. An object of the present invention is to provide a quartz glass member for a semiconductor manufacturing apparatus.

[0006]

A quartz glass member for a semiconductor manufacturing apparatus according to the present invention is capable of seeing through a linear or strip-shaped energizing heat-generating metal layer having electrodes at both ends on a quartz glass substrate. It is characterized by being formed at an arrangement density and covering the surface of the quartz glass substrate on which the metal layer is formed with an alumina protective film of 1 μm or more.

That is, according to the present invention, a linear or strip-shaped electrothermal thin film layer made of a current-generating metal such as nickel or nickel chromium acting as a so-called heating wire can be seen through a quartz glass substrate. It is characterized in that it is disposed in such a state that the plate surface is heated and heated, and the plate surface on which the electrothermal thin film layer is disposed is covered and protected with an alumina protective film having a specific thickness or more. As described above, in the present invention, by covering the surface with an alumina protective film, the surface has sufficient corrosion resistance to active species such as the fluorine-based plasma, and even when used for a long time, the surface is eroded and clouding occurs. There is no occurrence, and transparency can be maintained. Further, by covering the surface with the alumina protective film, it is possible to prevent corrosion of the electrothermal thin film layer formed of nickel, nickel chromium, or the like that acts as a heating wire formed on the quartz glass substrate, thereby preventing disconnection. The thickness of the alumina protective film needs to be 1 μm or more in order to sufficiently protect against corrosion of fluorine-based gas plasma.

Further, in the present invention, based on the knowledge that adhesion and deposition of this type of resinous substance can be suppressed by maintaining the glass surface temperature at a predetermined temperature or higher, nickel chromium is applied to the surface of the quartz glass member. Because the linear thin film layer of a metal acting as a heating wire such as an alloy is disposed so as not to impair the transparency, the resinous fluorocarbon polymer as described above does not adhere to the quartz glass member surface, The translucency does not decrease.

As described above, the quartz glass member of the present invention is capable of adhering and depositing a fluorocarbon polymer without impairing the excellent heat resistance, mechanical properties, insulating properties, and light transmittance inherent to quartz glass. , And various characteristics that are very suitable for window members for semiconductor manufacturing equipment and the like that maintain corrosion resistance due to fluorine-based active species.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view of a surface of a quartz glass member (viewing window material) for a semiconductor manufacturing apparatus according to the present invention mounted on the inside of a chamber, FIG. 2 is a rear view of FIG. 1, and FIG. FIG. 4 is an explanatory view showing a mounted state of a quartz glass member (viewing window material) for a semiconductor manufacturing apparatus according to the present invention. In the figure, a quartz glass member 1 for a semiconductor manufacturing apparatus has a surface 1a of a surface (FIG. 1) facing the inside of the chamber when mounted on a semiconductor manufacturing apparatus 10.
In addition, a strip-shaped metal film layer 2 acting as a heating wire is formed. The metal film layer 2 is transparent so that when the quartz glass member 1 for a semiconductor manufacturing apparatus is mounted on the semiconductor manufacturing apparatus 10, the surface exposed to the inside of the chamber can be uniformly heated, and the internal state can be observed from the outside. For example, they are arranged in an arrangement pattern as shown in FIG.

As shown in FIG. 3, a protective thin film layer 4 made of alumina is formed on the surface of the quartz glass on which the heating element metal film pattern layer 2 is provided. Protect from corrosion by. In the case of the illustrated quartz glass member, both ends 2a, 2a of the metal film layer 2 go around the back surface (FIG. 2), and the electrode nut 3 serving as an electrode uses a conductive paste 6 as shown in FIG. It is attached to a concave portion 1b near the periphery of the back surface of the quartz glass 1. As the quartz glass used as the base material for the quartz glass member for a semiconductor manufacturing apparatus of the present invention configured as described above, any of synthetic quartz glass and natural raw material fused quartz glass may be used according to the purpose. As the metal forming the linear or strip-shaped metal film layer 2 acting as a heating wire, a current-generating heat-generating metal that does not cause separation even when heated to 200 ° C. or higher is used. Examples thereof include Ni, Ni-Cr alloy, Mo, W, and C. If there is a problem in the adhesion between the quartz substrate and the metal layer, Cr, Mn, Sb, Ti, or the like is formed as the intermediate layer.

In the present invention, the heating element metal layer is formed on the surface of the quartz glass substrate (the surface facing the inside of the chamber when mounted on the semiconductor manufacturing apparatus 10). For example, the above metal, vacuum deposition,
A metal thin film layer is formed on the quartz surface by using a method such as sputtering or plating, and is formed into an appropriate pattern as a current-generating heating element having a linear shape or a thin band shape by masking or photolithography at the time of film formation. it can. It is preferable that the current-carrying heating element layer is usually formed to have a line or narrow band width of about 0.3 mm to 3 mm and a thickness of about 0.1 μm to 10 μm.

Next, an alumina protective film 4 is formed on the surface of the quartz glass member on which the heating element metal film layer 2 is formed, and the excellent heat resistance, mechanical properties and insulating properties inherent to the quartz glass are inherently provided. Protects the quartz glass surface, which has been heated to a high temperature by heating, from corrosion by activated chemical species of fluorine-based gas present in the device without impairing the light transmission, etc., and prevents inconvenience such as disconnection due to corrosion of the electrothermal metal layer. To prevent. The alumina coating constituting this alumina protective film is not particularly limited as long as it has high corrosion resistance to plasma activated species of fluorine-based gas and has good light transmission, and an alumina coating formed by an ordinary method is used. Can be used.

As the alumina film forming method, for example, a method of forming an alumina film by subjecting quartz glass on which the above-mentioned metal film layer is formed to high-frequency sputter coating treatment can be mentioned. More specifically, the above-mentioned predetermined quartz glass member is arranged in a sputtering film forming chamber, and high-purity alumina having a purity of, for example, 99% or more is used as a target.
Oxygen-containing argon gas mixed with about 0.05 to 10% by volume of oxygen gas is circulated under a pressure of about 0.05 to 10 Pa, and is subjected to high-frequency discharge in an atmosphere of 400 ° C. or less to generate plasma, A ring treatment is performed to form a target alumina film on the surface of the quartz glass. The thickness of the alumina coating must be 1 μm or more, and if the thickness is smaller than this, corrosion protection against plasma of fluorine-based gas is not sufficient. In the case of the present invention, the film thickness is usually preferably 1 μm to 50 μm. The sputter coating processing conditions such as sputtering pressure, gas composition, sputtering power, target substrate distance, and processing time are appropriately adjusted to a predetermined thickness. Formed. As a preferred alumina coating, a ratio of aluminum (Al) to oxygen (O) (Al /
O) is 1 / 1.4 to 1 / 1.6 and the purity is 95 to 9
A coating made of 9.5% amorphous alumina can be mentioned, and such an alumina coating is particularly excellent in fluorine gas plasma corrosion resistance and light transmission. Also, 40
Since the amorphous alumina film is formed in a low temperature range of 0 ° C. or lower, the thermal expansion coefficient of the film is close to that of the quartz glass substrate, and a uniform film without cracks or the like can be formed.

In the quartz glass member for a semiconductor manufacturing apparatus according to the present invention, after the alumina protective film is formed, if an electrode portion is provided on the side and back surfaces of the quartz glass, an insulating material is provided on the back surface electrode portion. Therefore, it is preferable to cover with the heat resistant resin 5. As the coating resin 5, a heat-resistant resin that does not peel at a high temperature, such as a heat-resistant epoxy resin, a silicone resin, or a polyimide resin, can be used. In addition, the quartz glass member for a semiconductor manufacturing apparatus of the present invention is provided with a temperature measuring member such as a thermocouple for monitoring and monitoring the surface temperature of the member when the electric heating metal layer is energized during use. The quartz glass member provided with such a temperature measuring member is very useful because the surface temperature of the member can be appropriately adjusted in accordance with its use environment.

Next, referring to FIGS. 4 and 5, a description will be given of the mounting structure and operation in use of the above-configured quartz glass for a semiconductor manufacturing apparatus of the present invention as a viewing window with reference to FIGS. Reference numeral 10 in the figure indicates a semiconductor manufacturing apparatus,
A flange portion 10a formed for attaching the quartz glass member 1 for a semiconductor manufacturing device is formed on a side portion of the semiconductor manufacturing device 10. And this flange part 1
The quartz glass fixture 1 for a semiconductor manufacturing apparatus is attached to the semiconductor manufacturing apparatus 10 via an O-ring 8 by fixing the quartz glass fixture 7 with bolts 9. Further, this quartz glass member 1 for a semiconductor manufacturing apparatus
The power supply controller 11 has a lead 1
2 are connected.

When such an apparatus 10 is used, a current is supplied from the power supply controller 11 to heat the surface of the quartz glass member 1 for a semiconductor manufacturing apparatus to 150 to 200 ° C. during operations such as dry etching. As a result, the deposition of the fluorocarbon polymer is suppressed, and the translucency is not lost.
Further, since the surface of the quartz glass 1a on which the metal film layer 2 is formed is covered with the alumina protective film 4, even if the surface of the member becomes high in temperature, it can be protected from corrosion by plasma activated species of fluorine-based gas. it can.

In the above embodiment, as shown in FIG. 3, an electrode nut 3 serving as an electrode is attached to the concave portion 1b near the periphery of the back surface of the quartz glass 1 using a conductive paste 16, as shown in FIG. However, the present invention is not particularly limited to this, and the electrode structures shown in FIGS. 6 and 7 may be used. That is, as shown in FIG. 6, the terminal electrode 13 is inserted into the concave portion 15 formed in the quartz glass 1, electrically connected to the metal film 2 using the conductive paste 6, and using the sealing glass 14. May be fixed. Further, as shown in FIG. 7, the terminal electrode 3 is inserted into the concave portion formed in the quartz glass 1, electrically connected to the metal film 2 using the conductive paste 16, and using the heat-resistant adhesive 17. May be fixed.

[0019]

The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by the following examples. (Manufacture of quartz glass substrate) A transparent quartz glass material was processed into a disk having a diameter of 60 mm and a thickness of 3 mm, the surface thereof was polished, and the processed product was boiled in a mixed solution of concentrated sulfuric acid and hydrogen peroxide. A plurality of dried quartz glass substrates were prepared by washing to remove contaminants on the surface. One of the quartz glass substrates was used as it was as a conventional product as it was, and eight were used for the sample members of Examples 1 to 4 and Comparative Examples 1 to 4, respectively. In Examples 1 to 4 and Comparative Examples 1 to 4, a concave portion for embedding an electrode nut was formed on one surface of a quartz glass disk before polishing.

(Formation of Metal Film Layer) The quartz glass substrates of Examples 1 to 4 and Comparative Examples 1 to 4 were set on a sputter device, and a metal film was formed on the front surface and a part of the side and back surfaces. As a metal for forming an electrothermal film, Ni was used in Examples 1 and 2 and Comparative Examples 1 and 3, and Ni was used in Examples 3 and 4 and Comparative Examples 2 and 3.
For No. 4, Ni-Cr was used. Then, a resist was applied to each of the quartz glass substrates coated with a metal film, and after drying, a film on which a wiring pattern of a heating wire was drawn was overlaid, and the pattern was baked by exposure to ultraviolet rays. After the development, the resultant was treated with an etching solution to obtain a quartz glass plate having a metal film heating wire pattern formed thereon.

(Formation of Electrode) An electrode nut for attaching a terminal was adhered to the recess formed in the obtained quartz glass plate with a metal film for embedding the electrode using a conductive paste.

(Formation of Alumina Protective Film) Of the above quartz glass plates on which the metal film layer is formed, Examples 1 to 4 and Comparative Example 3,
The glass plate of No. 4 was fixed to a substrate holder of a sputtering apparatus, and an alumina target was used to form an alumina protective film on the heating wire side by using an alumina target. Sputter coating of alumina was performed in the following manner. That is, a high-frequency magnetron sputter device was used as a sputtering device, and a surface of the quartz glass plate on the side of the electrothermal metal film layer was subjected to sputter coating using a high-purity (99% or more) alumina target and flowing argon gas. The thickness of the formed alumina protective film was 0.5 μm in Comparative Examples 3 and 4, and 2 in Examples 1 and 3.
μm, and that of Examples 2 and 4 was 6 μm. A heat-resistant resin was applied to the side and rear electrode portions for insulation.
Table 1 summarizes the properties of the quartz glass sample members of these examples, comparative examples, and conventional examples.

(Quartz Glass Member Evaluation Test) The sample quartz glass plate obtained as described above was subjected to a dry etching apparatus (magnetron RIE) as shown in FIGS.
The apparatus was installed as a viewing window for internal observation of the apparatus, and a corrosion resistance test (etching rate) and a light transmission test (linear transmittance of visible light) of fluorine-based gas with respect to plasma activated species were carried out under the conditions (Table 2) shown below. The etching rate test was performed under the conditions in Table 2 and the visible light linear transmittance test was performed under the conditions 1 and 2). Table 3 shows the results of the etching rate evaluation, and Table 4 shows the results of the evaluation of the linear transmittance of visible light.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

[Table 3] Note: The etching rate is a value obtained by measuring the corrosion level difference between the outer side of the O-ring and the inner side exposed to gas for the quartz glass plate used in the condition 1.

[0027]

[Table 4]

From the results shown in Tables 3 and 4, the quartz glass plates of Examples 1 to 4 in which the surface of the glass plate was heated with an electrothermal metal film layer and covered and protected with an alumina protective film thicker than 0.5 μm were obtained. Superior in corrosion resistance and translucency compared to conventional products without a layer and a protective film, especially because corrosion does not progress at all even when used for a long time (50 hours or more) and there is no adhesion of polymers and the like. The translucency is extremely good. On the other hand, Comparative Example 1 having only the electrothermal metal film heating layer and not providing the alumina protective film,
In the quartz glass plates of No. 2 and the quartz glass plates of Comparative Examples 3 and 4 in which the thickness of the alumina protective film was less than 1 μm, the adhesion of the polymer was small, but the corrosion proceeded because the glass surface temperature was higher than that of the conventional product. Was done.

[0029]

According to the quartz glass member for a semiconductor manufacturing apparatus of the present invention, a metal film acting as a heating wire is formed on the quartz glass surface, and the temperature of the glass surface during use is maintained at a high level. And can maintain excellent light transmittance even when used for a long time. In addition, by coating the surface of the quartz glass on which the metal film is formed with an alumina protective film, the corrosion resistance to plasma of the fluorine-based gas is higher than that of a conventional quartz glass member, and the fluorine-based gas used in the semiconductor manufacturing process is used. It is extremely suitable as a member such as a viewing window in a dry etching apparatus using plasma or a plasma PVD apparatus.

[Brief description of the drawings]

FIG. 1 is a front view of the inside of a chamber of a quartz glass member (viewing window) for a semiconductor manufacturing apparatus according to the present invention.

FIG. 2 is a rear side view of FIG. 1;

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a schematic sectional view showing a mounted state of a quartz glass member (viewing window) for a semiconductor manufacturing apparatus of the present invention.

FIG. 5 is a schematic perspective view showing a mounted state of a quartz glass member (viewing window) for a semiconductor manufacturing apparatus of the present invention.

FIG. 6 is a sectional view showing another structure of the electrode terminal portion.

FIG. 7 is a sectional view showing another structure of the electrode terminal portion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Quartz glass plate for semiconductor manufacturing equipment 1a Surface of quartz glass plate facing inside of chamber 1b Concave portion 2 Metal film 3 Nut for electrode 4 Alumina protective film 5 Heat resistant resin 6 Conductive paste 7 Quartz glass fixture 8 O ring 9 Bolt DESCRIPTION OF SYMBOLS 10 Semiconductor manufacturing apparatus 11 Power supply controller 12 Conductor 13 Terminal electrode 14 Sealing glass 15 Concave part 16 Conductive paste 17 Heat resistant adhesive

Claims (5)

[Claims] 1. A quartz glass substrate having, on a quartz glass substrate, a linear or strip-shaped energizing heat-generating metal layer having electrodes at both ends at a transparent arrangement density, and the metal layer formed thereon. A quartz glass member for a semiconductor manufacturing apparatus, the surface of which is coated with an alumina protective film of 1 μm or more. 2. The quartz glass member for a semiconductor manufacturing apparatus according to claim 1, wherein said alumina protective film is made of alumina having an amorphous structure. 3. The quartz glass member for a semiconductor manufacturing apparatus according to claim 1, wherein the thickness of the alumina protective film is 1 μm to 50 μm. 4. The quartz glass substrate is a quartz glass plate, the energized heat-generating metal layer and the alumina protective film are disposed on the front surface of the plate surface, and the electrodes are disposed on the side surface or near the periphery of the rear surface. And at least the electrode arrangement portion is covered with a heat-resistant resin.
A quartz glass member for a semiconductor manufacturing apparatus according to claim 3. 5. The quartz glass plate according to claim 4, wherein the electrode is disposed near the periphery of the back surface of the quartz glass plate, and a side surface of the quartz glass plate and a portion where the electrodes are disposed are covered with a heat-resistant resin. 4. A quartz glass member for a semiconductor manufacturing apparatus according to claim 1.