JP2000345319A - Manufacture of transmission window, transmission window, and processing device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a transmission window having a protective film in which cracks or peeling hardly occur and which has large adhesive force. SOLUTION: In a manufacturing method of a transmission window 30 of a treatment device for performing a specified treatment to a work W in a treatment container 4 which can be evacuated, a protective film 36 consisting of an alumina (Al2O3) crystalline film of <=1.0 μm in thickness at temperatures of <=350 deg.C is formed on a surface of a transmission plate 34 of the transmission window. In the obtained protective film, cracks or peeling occur hardly and large adhesive force is realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a transmission window, a transmission window, and a processing apparatus using the same.

[0002]

2. Description of the Related Art Generally, in a process of manufacturing a semiconductor integrated circuit, a film forming process is performed on a surface of a semiconductor wafer as an object to be processed.
Various processes such as an oxidation diffusion process, an etching process, and a modification process are repeatedly performed. Further, if necessary, a cleaning process for removing an unnecessary film adhered to the inside of the processing container of the processing apparatus is performed in order to suppress generation of particles that cause a reduction in yield. By the way, in order to perform the above-mentioned various treatments, a gas having a very corrosive property may be used. In the case where a transmission window made of quartz glass is provided in the treatment apparatus due to the corrosive gas, this gas may be used. A phenomenon in which the transparency of the transmission window deteriorates due to corrosion and white turbidity of the surface of the transmission window, that is, so-called devitrification occurs. As the corrosive gas, there is a halogen gas or a halogen compound gas,
For example, there are a WF ₆ gas used for forming a tungsten metal film or a metal-containing film, a ClF-based gas such as ClF ₃ used as a cleaning gas, and an HF-based gas.

When such devitrification occurs, for example, in a processing apparatus using a heating lamp, a transmission window through which heat rays from the heating lamp pass cannot be efficiently introduced into the processing apparatus. In the case of a processing apparatus that has been used, a transmission window through which light from the plasma passes to detect plasma etching or the like becomes difficult to transmit light, and further, a reforming process in which the film on the wafer surface is modified using ultraviolet rays. In the case of the device, the transmission window through which ultraviolet rays pass becomes difficult to transmit light. Therefore,
In order to eliminate the above-mentioned devitrification, the surface of such a quartz gas transmission window is, for example, disclosed in JP-A-53-146717, JP-A-54-3118, and JP-A-9-9577.
As disclosed in Japanese Unexamined Patent Publication No. 9-95772 and Japanese Patent Application Laid-Open No. 9-95772, a protective film made of an Al ₂ O ₃ film or the like having a predetermined thickness is coated.

[0004]

According to the method of coating an Al ₂ O ₃ film as described above, the occurrence of devitrification can be prevented. Due to repeated thermal rise and fall, large thermal stress is applied to the coating protective film, which causes cracks in the coating protective film or peels off of the protective film, resulting in a problem that the adhesion is not so high. was there. In order to solve this problem, there may be a case where a protective film is provided in a double manner, but in this case, there is a problem that a film forming process is complicated. The present invention has been devised in view of the above problems and effectively solving them. An object of the present invention is to provide a method of manufacturing a transmission window having a protective film having a large adhesion that does not easily cause cracking or peeling, a transmission window, and a processing apparatus using the same.

[0005]

Means for Solving the Problems As a result of intensive studies on the protective film coated on the transmission window, the present inventors have found that by optimizing the temperature and thickness when depositing the protective film, it is possible to further form the film. The present invention has been made based on the finding that a protective film having excellent adhesion can be formed by optimizing the method. The invention as defined in claim 1 is a method for manufacturing a transmission window of a processing apparatus for performing a predetermined process on an object to be processed in a processing container capable of being evacuated, wherein 35
Alumina (Al) having a thickness of 1.0 μm or less at a temperature of 0 ° C. or less
_A protective film made of a ₂ O ₃ ) crystal film is formed. As a result, the adhesion of the protective film can be greatly improved, cracks and peeling can be prevented, and the durability against repeated temperature rises and decreases can be improved.

According to a second aspect of the present invention, there is provided a method of manufacturing a transmission window of a processing apparatus for performing a predetermined process on an object to be processed in a processing chamber capable of being evacuated. Alumina (Al ₂ O) having a thickness of 1.0 μm or less in the vicinity of a substantially intermediate temperature between a temperature to which the transmission window is exposed and a normal temperature when the object is subjected to a predetermined process.
₃ ) A protective film made of a crystalline film is formed. Thereby, while minimizing the thermal stress generated due to the temperature difference between when the processing device is operating and when it is stopped,
By greatly improving the adhesion of the protective film, cracks and peeling can be prevented, and the durability against repeated temperature rises and decreases can be improved.

In this case, if the alumina crystal film is formed using a high-frequency ion plating method, the adhesion of the protective film can be further improved. Become. Further, as defined in claim 4, for example, the transmission window is a lamp transmission window for transmitting heat rays from the heating lamp when the heating means of the processing apparatus is a heating lamp. Further, as defined in claim 5, for example, the transmission window is a plasma transmission window that transmits light from the plasma when the processing apparatus uses plasma.

Further, as defined in claim 6, for example, the transparent plate of the transmission window is made of quartz glass. Claim 7
Specifies a transmission window manufactured by the above method invention, and claim 8 specifies a processing apparatus using the transmission window.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a method for manufacturing a transmission window, a transmission window and a processing apparatus using the same according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing a processing apparatus using a transmission window according to the present invention, and FIG. 2 is an enlarged sectional view showing a transmission window according to the present invention. Here, as an example of a processing apparatus, a film forming processing apparatus that deposits a tungsten film using WF ₆ as a highly corrosive film forming gas will be described. The film forming apparatus 2 includes a processing container 4 formed into a cylindrical shape or a box shape from, for example, aluminum or the like, and a cylindrical reflector standing upright from the bottom of the processing container. A mounting table 10 for mounting a semiconductor wafer W as an object to be processed is provided on 6, for example, via a holding member 8 having an L-shaped cross section. The reflector 6 is made of, for example, aluminum for the purpose of reflecting lamp light, and the holding member 8 is made of a material having low heat conductivity, for example, quartz for the purpose of shielding the mounting table 10 from heat conduction. The mounting table 10 is made of, for example, a carbon material having a thickness of about 1 mm, an aluminum compound such as AlN, or the like.

Below the mounting table 10, a plurality of, for example, three lifter pins 12 are provided with a circular ring-shaped support member 14.
The lifter pin 1 is moved up and down by a push-up rod 16 provided through the bottom of the processing container.
2 is inserted into a lifter pin hole 18 provided to penetrate the mounting table 10 so that the wafer W can be lifted.
The lower end of the push-up bar 16 is connected to an actuator 22 via a bellows 20 which can be expanded and contracted in order to keep the inside of the processing container 4 airtight. In order to hold the peripheral portion of the wafer W and fix the peripheral portion of the wafer W to the mounting table 10, for example, a substantially ring-shaped ceramic clamp ring 24 is provided along the contour of the wafer. Have been. The clamp ring 24 is connected to the support member 14 via a support bar 26 that penetrates the holding member 8 in a loosely fitted state, and moves up and down integrally with the lifter pin 12. Here, the holding member 8
A coil spring 28 is provided on a support rod 26 between the
Are provided to assist the descent of the clamp ring 24 and the like, and to ensure the clamping of the wafer. These lifter pins 12, support member 14, and holding member 8 are also formed of a heat ray transmitting member such as quartz.

At the bottom of the processing vessel directly below the mounting table 10, a transmission window 30 made of a heat ray transmission material such as quartz is provided in a gas-tight manner via a sealing member 32 such as an O-ring. I have. As shown in FIG. 2, the transmission window 30 is entirely formed in a disk shape. As shown in FIG. 2, a transparent plate 34 made of, for example, quartz glass and alumina (Al ₂ O) coated on the inner surface side exposed to a processing gas are used. ₃ ) It is composed of a protective film 36 made of a crystalline film. This transparent plate 3
The thickness T1 of the protective film 36 is set to, for example, about 15 mm so as to withstand the pressure difference between the inside and outside of the processing container 4.
Is set to 1.0 μm or less in order to enhance the adhesion to the transparent plate 34. This protective film 36
For example, the film is formed using a high frequency (RF) ion plating method or the like, and this film formation method will be described later. Below the transmission window 30, a box-shaped heating chamber 38 is provided so as to surround the transmission window 30. In the heating chamber 38, a plurality of heating lamps 40 as heating means are mounted on a turntable 42 also serving as a reflecting mirror.
Is rotated by a rotation motor 44 provided at the bottom of the heating chamber 38 via a rotation shaft. Therefore, this heating lamp 40
The emitted heat rays pass through the transmission window 30 for the lamp and irradiate the lower surface of the mounting table 10 to heat it.

A ring-shaped rectifying plate 48 having a large number of rectifying holes 46 is provided on the outer peripheral side of the mounting table 10 so as to be supported by a support column 50 formed in a vertically annular shape. A ring-shaped quartz attachment 52 is provided on the inner peripheral side of the current plate 48 so as to contact the outer peripheral portion of the clamp ring 24 and prevent gas from flowing thereunder. An exhaust port 54 is provided at a bottom portion below the current plate 48, and an exhaust path 56 connected to a vacuum pump (not shown) is connected to the exhaust port 54 to maintain the inside of the processing chamber 4 at a predetermined degree of vacuum. It is possible to do. In addition, a gate valve 58 that is opened and closed when a wafer is loaded and unloaded is provided on a side wall of the processing container 4.

On the other hand, a shower head unit 60 for introducing a processing gas or the like into the processing container 4 is provided on a ceiling portion of the processing container facing the mounting table 10. Specifically, the shower head unit 60 has a head main body 62 formed in a circular box shape from, for example, aluminum or the like,
A gas inlet 64 is provided in the ceiling. A gas necessary for processing, for example, a gas source such as WF ₆ , Ar, SiH ₄ , H ₂ , N ₂ or a cleaning gas source such as ClF ₃ can be flow-controlled at the gas inlet 64 through a gas passage. It is connected. At the lower part of the head main body 62, a number of gas injection holes 66 for discharging the gas supplied into the head main body 62 to the processing space S are arranged over substantially the whole surface, and the gas is spread over the wafer surface. Is to be released. Further, a diffusion plate 70 having a large number of gas dispersion holes 68 is provided in the head main body 62 so as to supply gas more evenly to the wafer surface.

Next, a description will be given of a film forming method performed by using the above-configured apparatus. First, the gate valve 58 provided on the side wall of the processing container 4 is opened, the wafer W is loaded into the processing container 4 by the transfer arm, and the lifter pins 12 are pushed up to move the wafer W to the lifter pins 12.
Hand over to the side. Then, the lifter pins 12 are lowered by lowering the push-up bar 16, the wafer W is placed on the mounting table 10, and the peripheral portion of the wafer W is pressed by the clamp ring 24 by further lowering the push-up bar 16. Is fixed.

Next, WF ₆ (source gas), SiH ₄ , H ₂ , Ar, N _{2 are used} as processing gases from a processing gas source (not shown).
A required amount of gas is supplied to the shower head unit 60 by a predetermined amount and mixed therewith, and the gas is supplied substantially uniformly into the processing container 4 from the gas injection holes 66 on the lower surface of the head main body 62. At the same time, the interior of the processing container 4 is set to a predetermined degree of vacuum by sucking and exhausting the internal atmosphere from the exhaust port 54, and the heating lamp 40 located below the mounting table 10 is driven while rotating, so that heat is generated. Emits energy. The emitted heat rays pass through the transmission window 30 for the lamp, and then irradiate the back surface of the mounting table 10 to heat it. Since the mounting table 10 is very thin, about 1 mm, as described above, it is quickly heated. Therefore, the wafer W mounted thereon can be quickly heated to a predetermined temperature. The supplied mixed gas causes a predetermined chemical reaction, and, for example, a tungsten film is deposited and formed on the wafer surface according to the film forming conditions.

During such a film forming process, the film forming gas supplied to the processing space S flows into the back surface of the mounting table 10 through a contact gap between the clamp ring 24 and the wafer W or the attachment 52. Inevitably, this corrosive film forming gas, that is, WF _6, is transmitted through the transmission window 30.
However, since the protective film 36 made of an alumina crystal film (sapphire film) is formed on this surface, corrosion is prevented and devitrification does not occur here.
For the same reason, a highly corrosive gas such as ClF ₃ gas comes into contact with the transmission window 30 even during a cleaning operation for removing an unnecessary adhered film in the processing container 4. Will not occur.

Although depending on the process temperature, the transmission window 3
The temperature of 0 itself is exposed to repeated temperature rises and falls between a temperature of 700 ° C. or more and a normal temperature, for example, a temperature of about 25 ° C. due to repetition of operation and stop of the apparatus, and a large thermal stress is added. Since the protective film 36 formed by the method of the present invention has a particularly large adhesive force, it is possible to prevent cracks, peeling, and the like from occurring on the protective film 36. Here, a method for forming the protective film 36 of the transmission window 30 will be described more specifically. The protective film 36 is mainly formed by using a high frequency ion plating method, but may be formed by a sputtering method, a vapor deposition method, or the like. FIG. 3 is a schematic diagram showing an example of a high-frequency ion plating apparatus, in which a crucible 76 containing aluminum 74 as an evaporation source is arranged at the bottom of a vacuum chamber 72 which can be evacuated, and a ceiling opposed to the crucible 76 is provided. The transparent plate 34 supported on the substrate support base 78 having a temperature adjustment function is installed in the section. A negative voltage is applied to the substrate support base 78 from a DC power supply 80 to form, for example, a negative electrode (cathode), and the aluminum 74 is grounded. A high-frequency oscillation coil 84 is provided so as to cover the crucible 76, and the coil 84 is connected to a high-frequency power supply 82.

In this apparatus, evaporated particles are positively ionized in the vacuum chamber 72 by using a high-frequency electric field. Ar gas and O ₂ gas are introduced as gases into the vacuum chamber 72, and a negative DC voltage is applied to the transparent plate 34 side. Then, a high-frequency discharge is caused by the applied high-frequency electric field, and Al generated from the crucible 76 is generated.
Some of the evaporated particles are ionized by a high-frequency electric field, or collide with a gas ionized by a high-frequency discharge to become ionized particles. Then, the ionized particles are accelerated and collide with the transparent plate 34 serving as a cathode and collide with vapor deposition, and the alumina (Al ₂ O ₃ ) crystal film, that is, the protective film 3 is formed on the surface of the transparent plate 34.
6 (see FIG. 2).

<Evaluation of Examples 1 to 8 and Comparative Examples 1 to 4>
Here, the film formation method is a high-frequency ion plating method,
Various changes to the sputtering method and evaporation method
The film formation temperature is set to 100 to 350 ° C. within the range of
The alumina crystal film was formed with various changes within the range described above, and the adhesion was evaluated. The results will be described with reference to FIG. 4 as Examples 1 to 8 and Comparative Examples 1 to 4. . In the drawings, RFIP of the film forming method indicates a high-frequency ion plating method. First, as shown in Comparative Examples 1 to 4, the film thickness was 2.0 μm and the film formation temperature was 200 to 350 ° C.
According to the heat cycle test results, it is not preferable because the film is peeled off even at a low temperature. However, as shown in Examples 1 to 7, the film forming temperature is 350 ° C. or less and the film thickness is 0.3
In the case of μm or less, there is no crack by visual appearance evaluation without depending on the above three film forming methods, and no peeling of the film is observed even in a heat cycle test by raising and lowering the temperature to 700 ° C. It has been found that the properties are very high and good results can be obtained.

As shown in Embodiment 8, the film thickness is 1.
When the film formation temperature was 350 ° C. at 0 μm,
7, the adhesion was deteriorated, and the heat cycle test up to 400 ° C. was good, but the heat cycle test up to 500 ° C. showed peeling. Therefore, the alumina crystal film shown in the eighth embodiment is suitable for a process in which the temperature of the transmission window 30 (see FIG. 1) itself rises only up to about 400 ° C. (the wafer temperature becomes about 500 ° C.). Has been found to be usable as a protective film.
Further, as shown in Comparative Examples 2 and 4, when the film formation temperature was 200 ° C. and the film thickness was 2.0 μm under the same conditions and only the film formation method was different, the high frequency ion plating method was used as the film formation method. The heat cycle test result of Comparative Example 3 using を was better up to 300 ° C., and the adhesion was found to be one rank higher than Comparative Example 4. Therefore, it has been found that it is better to use a high-frequency ion plating method than a vapor deposition method as a film forming method. The reason why the high-frequency ion plating method is preferable is that, in the case of this method, the excitation of gas molecules is easy and stable due to the action of the high-frequency electric field, so that the gas pressure of a high vacuum (about 10 ^-4 Torr) can be used. Discharge is maintained. As a result, it is assumed that a dense film with few defects is formed.

Further, as described above, when the film thickness is increased to about 2.0 μm, the reason why peeling occurs is that as the film thickness increases, the internal stress in the film also increases, and This is probably because the crystal film becomes unbearable. Furthermore, the thickness of the alumina crystal film is preferably as small as possible in consideration of the generated thermal stress, but the minimum value of the film thickness is 0.1 in consideration of the corrosion resistance to the corrosive gas to be used and the film formation technique. It is about 01 μm (= 100 °).
For each of Examples 1 to 8, a scratch test for examining the tensile peel strength and a Sebastian test for examining the scratch resistance were carried out. As a result, good results without any problem could be obtained.

Furthermore, the film forming temperature of the alumina crystal film is:
When a predetermined process is performed on a semiconductor wafer as an object to be processed, it is preferable that the film formation process is performed near a temperature at which the transmission window is exposed and a room temperature, for example, a temperature approximately in the middle of 25 ° C. According to this, alumina (Al
The difference in the coefficient of thermal expansion between the ₂ O ₃ ) crystal film and SiO ₂ , which is the material of the transparent plate 34 (see FIG. 2) as the base, can be minimized. For example, when the temperature of the transmission window at the time of processing returns from 350 ° C. to 25 ° C. of normal temperature, the length becomes 6 mm.
The amount of shrinkage in the direction of 0 mm is as follows for the protective film (Al ₂ O ₃ ) and the transparent plate (SiO ₂ ). Al ₂ O ₃ protective film: 325 (° C.) × 7.0 × 10 ⁻⁶ (/
° C) × 60 (mm) = 0.1365 mm SiO ₂ transparent plate: 325 (° C) × 4.0 × 10 ^-7 (/
° C) × 60 (mm) = 0.0078 mm Here, the linear thermal expansion coefficient of Al ₂ O ₃ is 7.0 × 10 ^-6 ,
The linear thermal expansion coefficient of SiO ₂ was 4.0 × 10 ⁻⁷ .

The difference between the two, 0.1287 mm, is a factor in the occurrence of thermal stress. To reduce the difference,
The alumina crystal film may be formed at both of the above temperatures, that is, at a temperature approximately between 350 ° C. and 25 ° C., for example, at a temperature near 162.5 ° C. In the above embodiment, the case where the transmission window is applied to a film forming apparatus using a heating lamp has been described as an example. However, the present invention is not limited to this. Other processing apparatuses using a corrosive gas, for example, a plasma processing apparatus Window for observing the inside of the semiconductor device, a plasma transmission window for transmitting light from the plasma to detect the etching end point of the plasma etching apparatus, and a modification for modifying the deposited film on the semiconductor wafer surface by ultraviolet irradiation in an ozone atmosphere. The present invention can also be applied to an ultraviolet transmission window of a quality processing apparatus.

For example, FIG. 5 is a schematic configuration diagram showing an example of a plasma etching processing apparatus as a processing apparatus. A mounting table 96 is provided in a vacuum-evacuable processing vessel 92 of the plasma etching processing apparatus 90.
The semiconductor wafer W is mounted on this upper surface. This mounting table 96
Are, for example, grounded to form a lower electrode. A shower head section 98 for introducing a plasma gas such as Ar and a processing gas into the processing chamber 92 while being insulated by the insulating member 100 is provided on a ceiling section facing the mounting table 96, and constitutes an upper electrode. ing. A high frequency power supply 104 of 13.56 MHz, for example, is connected to the shower head 98 via a matching circuit 102, and a high frequency voltage is applied between the upper and lower electrodes.

An opening 106 is formed in a part of the side wall of the processing container 92, and a plasma transmitting window 110 is formed in the opening 106 as a transmitting window via a seal member 108.
Are provided in an airtight manner, and a photodetector 112 for detecting light from the plasma is provided on the outside thereof in order to detect the end point of the etching. This plasma transmission window 110
Also, as described with reference to FIG. 2, a predetermined protective film 36 is formed on the transparent plate 34. Even in the case of this apparatus, it is possible to prevent the protective film 36 from being cracked or peeled off even when the plasma transmission window 110 is repeatedly exposed to temperature rise and fall. FIG. 6 is a schematic configuration diagram showing an example of an ultraviolet ray reforming apparatus as a processing apparatus. A mounting table 126 is provided in the processing container 122 of the ultraviolet reforming apparatus 120 which can be evacuated, and the semiconductor wafer W is mounted on the mounting table 126. Opposite to the mounting table 126, a transparent quartz ring-shaped shower head 128 for introducing ozone or the like into the interior.
Is provided.

A large opening 130 is formed in the ceiling of the processing container 122, and an ultraviolet transmission window 134 is provided in the opening 130 in an airtight manner via a sealing member 132 such as an O-ring. A plurality of ultraviolet lamps 138 housed in a casing 136 are disposed outside the ultraviolet transmission window 134, and ultraviolet radiation emitted from the ultraviolet lamp 138 is transmitted through the ultraviolet transmission window 134 to mount the mounting table 126. Irradiation is performed on the upper wafer surface to modify the surface film. The ultraviolet transmission window 134 is also provided on the transparent plate 34 with a predetermined protective film 36 as described with reference to FIG.
The protective film 36 can be prevented from cracking or peeling off. In the above embodiment, a semiconductor wafer has been described as an example of an object to be processed, but it is needless to say that the present invention can be applied to an LCD substrate and a glass substrate.

[0027]

As described above, according to the method for manufacturing a transmission window, the transmission window, and the processing apparatus using the same according to the present invention,
The following excellent functions and effects can be exhibited. A protective film made of an alumina crystal film having a thickness of 1.0 μm or less is formed on a transparent plate as a transmission window of the processing apparatus at a temperature of 350 ° C. or less, so that this adhesion is improved to prevent cracks and peeling. However, durability can be improved even with repeated temperature rise and fall. In addition, by setting the film forming temperature of the protective film to a temperature approximately in the middle between the temperature at which the transmission window is exposed during the process and the room temperature, the generated thermal stress can be greatly suppressed. Performance can also be improved. In particular, by using a high-frequency ion plating method when forming the protective film, the adhesion can be further improved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional configuration diagram showing a processing apparatus using a transmission window according to the present invention.

FIG. 2 is an enlarged sectional view showing a transmission window of the present invention.

FIG. 3 is a schematic configuration diagram illustrating an example of a high-frequency ion plating apparatus.

FIG. 4 is a diagram showing evaluation results of an alumina crystal film.

FIG. 5 is a schematic configuration diagram illustrating an example of a plasma etching processing apparatus as a processing apparatus.

FIG. 6 is a schematic configuration diagram illustrating an example of an ultraviolet reforming processing device as a processing device.

[Explanation of symbols]

 2 Film forming apparatus (processing apparatus) 4 Processing container 10 Mounting table 30 Transmission window 34 Transparent plate 36 Protective film 40 Heating lamp 72 Vacuum chamber 74 Aluminum 76 Crucible 82 High frequency power supply 84A, 84B High frequency electrode W Semiconductor wafer (workpiece)

Continued on the front page (72) Inventor Mitsuhiro Tachibana 650 Mitsuzawa, Hosaka-cho, Nirasaki-shi, Yamanashi Prefecture F-term in Tokyo Electron Yamanashi Co., Ltd. EC03 EK14 EM09 EM10 EN04

Claims (8)

[Claims] 1. A method for manufacturing a transmission window of a processing apparatus for performing a predetermined process on an object to be processed in a processing container which is capable of being evacuated, wherein 350
Alumina having a thickness of 1.0 μm or less (Al ₂
A method for manufacturing a transmission window, wherein a protective film made of O ₃ ) crystal film is formed. 2. A method for manufacturing a transmission window of a processing apparatus for performing a predetermined process on an object to be processed in a processing container which is capable of being evacuated, wherein a predetermined surface is provided on a surface of a transparent plate of the transmission window. A thickness of about 1.0 μm in the vicinity of a temperature substantially intermediate between the temperature to which the transmission window is exposed and the room temperature when performing the treatment of
A method for manufacturing a transmission window, comprising forming a protective film made of the following alumina (Al ₂ O ₃ ) crystal film. 3. The method according to claim 1, wherein the alumina crystal film is formed using a high-frequency ion plating method. 4. The lamp according to claim 1, wherein the transmission window is a lamp transmission window for transmitting heat rays from the heating lamp when the heating unit of the processing apparatus is a heating lamp. A method for producing the transmission window according to the above. 5. The plasma transmission window according to claim 1, wherein the transmission window is a plasma transmission window that transmits light from the plasma when the processing apparatus uses plasma.
The method for producing a transmission window according to any one of the above. 6. The method according to claim 1, wherein the transparent plate of the transmission window is made of quartz glass. 7. A transmission window manufactured by the method defined in claim 1. Description: 8. A processing apparatus in which a predetermined processing is performed on an object to be processed in a processing container that can be evacuated, wherein the processing container is provided with a transmission window defined in claim 7. A processing device characterized by the above-mentioned.