TW201738399A - Method for plasma process and photomask plate - Google Patents

Abstract

The invention discloses a method for plasma process. The method comprises: providing a dummy plate having silica in a chamber; generating a plasma having oxygen and chlorine in the chamber; generating a product by the reaction of the plasma with the dummy plate; and forming a protection film on an inner surface inside the chamber by the reaction of the product with the plasma.

Description

Process method for plasma processing and reticle sheet

The present invention relates to a process for plasma processing.

In the semiconductor industry, plasma technology can be applied to physical vapor deposition (PVD), chemical vapor deposition (CVD) or dry etching. For example, dry etching uses plasma technology in a chamber to dissociate molecules of a reactive gas into ions that are reactive with the material to be etched, and these ions chemically react with exposed portions of the substrate. Thereby part of the product will evaporate and be removed from the substrate, and then the pump will be used to extract the volatiles.

However, in the dry etching process, the plasma particles not only react with the substrate to be etched, but also the plasma particles collide or react with the inner wall of the chamber, or the insulating member, etc., which will cause wear of components in the chamber. Particles are generated in the chamber. Since the particles cause contamination of the substrate to be etched, if the particles in the chamber accumulate too much, the dry etching machine must suspend the production operation and clean the chamber, which will result in reduced production efficiency and increased manufacturing costs. .

It is an object of the present invention to provide a process for plasma processing and a reticle sheet that can be kept clean in a plasma treated chamber to prevent particulates from being generated from the chamber walls.

In one embodiment, a process for plasma processing includes: providing a sacrificial sheet containing cerium oxide into a chamber; generating a plasma containing oxygen and chlorine in the chamber; Sacrificing the reaction of the sheet to produce a product; and forming a protective film on a wall inside the chamber by reacting the product with the plasma.

In one embodiment, the product is barium tetrachloride, the material of the protective film is ceria, and the reaction between the plasma and the sacrificial plate is as shown in the following formula (1), and the reaction between the product and the plasma is as follows (2) :SiO ₂ +2C+2Cl ₂ ->SiCl ₄ +2CO Formula (1)

SiCl ₄ + O ₂ -> SiO ₂ + 2Cl ₂ Formula (2).

In one embodiment, the sacrificial sheet is an unprocessed reticle substrate.

In one embodiment, the method further includes: performing a plasma treatment on at least one of the sheets to be processed using the plasma; and maintaining the protective film at a stable thickness after the plasma treatment.

In one embodiment, the plasma treatment results in a reduction in the thickness of the protective film.

In one embodiment, the step of maintaining the protective film at a stable thickness comprises: providing a supplementary plate containing cerium oxide into the chamber; generating a product by reaction of the plasma and the supplementary plate; and by generating The reaction of the plasma thickens the protective film to maintain a stable thickness.

In one embodiment, the supplementary sheet material comprises a substrate and a plasma resistant film, wherein the substrate has an exposed area and a covering area and contains cerium oxide, wherein the plasma resistant film covers the covering area over a large area to prevent the covering area from being electrically The slurry reacts and allows the exposed area to react with the plasma. The material of the plasma resistant film is ceramic, wherein the increased thickness of the protective film depends on the area of the exposed area.

In one embodiment, the sacrificial sheet, the sheet to be processed, and the supplementary sheet have substrates of the same material.

In one embodiment, the stable thickness is 250 nm or less.

In one embodiment, a reticle sheet is used in the foregoing process method, including a substrate and a plasma resistant film. The substrate has an exposed area and a covered area, and the substrate contains cerium oxide. The plasma resistant film covers the covered area over a large area to prevent the covered area from reacting with the plasma and allows the exposed area to react with the plasma, wherein the increased thickness of the protective film depends on the area of the exposed area.

As described above, in the plasma processing method, both the sacrificial plate and the supplementary plate can be fed into or removed from the chamber by the existing conveying mechanism of the plasma processing device, thereby forming or supplementing the protective film. The material can be simply fed into the chamber without the need to stop the operation of the plasma processing equipment or open the chamber. In addition, the protective film of a stable thickness prevents particles from being generated from the wall surface or from the protective film itself, and the chamber of the plasma processing apparatus is thus kept clean, and the time required to clean the chamber is also prolonged, that is, the plasma processing apparatus is stopped and opened. The number of times the chamber is cleaned is reduced. Therefore, the plasma processing apparatus can continue the operation of the conventional plasma processing as much as possible, and maintain the state of manufacturing production instead of the maintenance shutdown state.

In addition, the supplementary sheet for supplementing the thickness of the protective film can be produced by using a mask substrate, and does not require an additional type of material substrate, so that it has the advantages of simple fabrication and low cost. Furthermore, the area of the exposed area of the supplementary sheet may be appropriately determined by the difference between the thickness of the thinned protective film and the stable thickness, thereby supplementing the sufficient but not excessive amount of cerium oxide to participate in the reaction in the chamber, thereby generating an appropriate amount. The cerium oxide is applied to the wall surface to thicken the protective film to a stable thickness.

1‧‧‧Pulp processing equipment

11‧‧‧Processing gas supply device

111‧‧‧Processing gas supply

112, 113‧‧‧ mass flow controller

114, 115‧‧‧ gas supply piping

12‧‧‧Spray structure

121‧‧‧Gas diffusion chamber

122‧‧‧Dissipating holes

123‧‧‧Upper board

13‧‧‧Exhaust device

14‧‧‧Sediment shelter structure

141‧‧‧ wall

142, 142a, 142b‧‧‧ protective film

16‧‧‧ chamber

17‧‧‧Export

18‧‧‧Loading station

181‧‧‧Insulated inner wall

182‧‧‧Insulation partition

183‧‧‧Support table

184‧‧‧Substrate

19‧‧‧ Carrier Board

191‧‧‧Insulation

192‧‧‧electrode

2‧‧‧ Plasma

3‧‧‧ sacrificial plates

4‧‧‧Wholes to be processed

5‧‧‧Replenishment plates

51‧‧‧Anti-plasma film

52‧‧‧Substrate

521‧‧‧ exposed area

522‧‧‧ Coverage area

6‧‧‧DC power supply

71‧‧‧ low pass filter

72‧‧‧ switch

73‧‧‧Variable DC power supply

81a‧‧‧First matcher

81b‧‧‧Second matcher

82a‧‧‧First AC power supply

82b‧‧‧second AC power supply

S1~S8‧‧‧Steps

V1, V2‧‧‧ opening and closing valve

1 is a flow chart of a process for plasma processing in an embodiment.

2A to 2C are schematic views showing a process of forming a protective film in an embodiment.

3A-3C are schematic views showing the reduction of the thickness of the protective film by performing conventional plasma treatment in one embodiment.

4A-4C are schematic views of maintaining a protective film at a stable thickness in an embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method for fabricating a plasma processing according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings, wherein the same elements and steps will be described with the same reference numerals. In the following embodiments and drawings, components and steps that are not directly related to the present invention are omitted and are not shown; and the dimensional relationships between the components in the drawings are merely for ease of understanding and are not intended to limit the actual ratio.

The plasma treatment process is, for example, Dry Etching, Plasma sputtering, Plasma coating, Plasma grafting. Dry etching includes Sputter Etching, Ion Beam Etching, Plasma Etching, and Reactive Ion Etching. In the chamber of the plasma processing equipment (dry etching machine), the plate (etched object) is fed into the chamber by a transport mechanism, and then the injected gas is applied with a voltage to generate plasma to etch the plate. . The product of the reaction of the plasma, sheet, or other components, as well as the generated particles, are then withdrawn from the chamber by means of an exhaust device. After the etching is completed, the sheet is removed from the chamber by the transport mechanism, and then the foregoing steps are repeated similarly to dry-etch the next sheet. In general, the use of a handling mechanism to transport sheets does not require shutdown or opening of the chamber.

1 is a flow chart of a method of plasma processing in accordance with an embodiment. As shown in FIG. 1, the process method includes the following steps S1 to S8: Step S1: providing a sacrificial plate containing cerium oxide into a chamber.

Step S2: generating a plasma containing oxygen and chlorine in the chamber.

Step S3: A product is produced by the reaction of the plasma and the sacrificial sheet.

Step S4: forming a protective film on a wall surface inside the chamber by reacting the product with the plasma, for example, forming on the inner wall of the chamber or forming a wall surface of the deposit shielding structure.

Step S5: Performing a plasma treatment on at least one sheet to be processed using plasma.

Step S6: providing a supplementary plate containing cerium oxide into the chamber.

Step S7: The product is produced by the reaction of the plasma and the supplementary plate.

Step S8: The protective film is thickened by the reaction of the product with the plasma to maintain a stable thickness.

In this embodiment, the process method can be applied to a plasma processing process for fabricating a photomask. On the other hand, in other embodiments, the process method can also be applied to a plasma processing process for fabricating other semiconductor components.

Before the conventional plasma treatment of the processed sheet material, the steps S1 to S4 of the processing method first form a stable protective film on the wall surface inside the chamber of the plasma processing apparatus.

The protective film separates the plasma from the wall of the chamber and prevents the wall from reacting with or being struck by the plasma, thereby preventing particles from being generated from the wall. Further, in addition to the protective surface of the protective film, the protective film itself does not easily fall off from the wall surface, and thus the generation of particles from the protective film can be reduced.

After the stable protective film is formed on the wall surface of the chamber of the plasma processing apparatus, the step S5 of the process method performs conventional plasma processing on the processed sheet material, for example, dry etching, plasma sputtering in the foregoing plasma processing process, Plasma coating, or plasma grafting, etc. This step can be repeated several times to process multiple sheets.

Then, since the protective film on the wall surface is thinned after the conventional plasma treatment, steps S6 to S8 appropriately thicken the protective film, so that the protective film is stably maintained on the wall surface, and continues to play in the aforementioned step S1. Up to the function in step S4.

In the process method, both the sacrificial plate and the supplementary plate can be processed by using plasma. The prepared transport mechanism is fed into or removed from the chamber, so that the material forming or supplementing the protective film can be simply fed into the chamber without stopping the operation of the plasma processing apparatus or opening the chamber. In addition, the protective film of a stable thickness prevents the particles from being generated from the wall surface or the protective film itself, and the chamber is thus kept clean, and the time required to clean the chamber is prolonged, that is, the number of times the plasma processing apparatus is stopped and the chamber is opened for cleaning. reduce. Therefore, the plasma processing apparatus can continue the operation of the conventional plasma processing and maintain the state of manufacturing production instead of the maintenance shutdown state.

In addition, in the process method, the material of the sacrificial plate, the substrate for replenishing the plate, and the substrate for the plate to be processed are both cerium oxide. In the step of forming the protective film or thickening the protective film, the gas required to produce the protective film may be the same as that required for conventional plasma processing, that is, both oxygen and chlorine are used. Therefore, the gas used may not be replaced during this process.

The steps of the plasma processing method will be described below with reference to FIGS. 2A to 2C, FIGS. 3A to 3C, and FIGS. 4A to 4C. Steps S1 to S4 will be described with reference to FIGS. 2A to 2C, and step S5 will be described with reference to FIGS. 3A to 3C. Steps S6 to S8 will be described with reference to Figs. 4A to 4C. In the following embodiments, the photomask is exemplified, but it is not limited to the mere production of the photomask.

2A-2C are schematic views showing a process of forming a protective film in an embodiment, wherein steps S1 to S4 of FIG. 1 are described with reference to FIGS. 2A to 2C.

Referring to FIG. 2A, a plasma processing apparatus 1 includes a chamber 16, a processing gas supply device 11, a spray structure 12, an exhaust device 13, a deposit shielding structure 14, a wall surface 141, and a transport mechanism. Not shown), an outlet 17, a carrier 18, and a carrier 19.

A process gas supply device 11 includes a process gas supply source 111, two mass flow controllers 112 and 113, and two gas supply pipes 114 and 115. One ends of the two gas supply pipes 114 and 115 are connected to the process gas supply source 111, and the other end is connected. Connected to the spray structure 12. On the gas supply pipe 114, a mass flow controller (MFC) 112 and an opening and closing valve V1 are sequentially provided from the upstream. Further, on the gas supply pipe 115, a mass flow controller (MFC) 113 and an opening and closing valve V2 are sequentially provided from the upstream. The spray structure 12 includes a gas diffusion chamber 121, a plurality of spray holes 122, and an upper plate 123.

The reaction gas is supplied from the processing gas supply device 11, and these gases are injected from the processing gas supply source 111 into the gas diffusion chamber 121 through the gas supply pipes 114 and 115, the mass flow controllers 112 and 113, and the opening and closing valves V1 and V2. From the gas diffusion chamber 121 via The spray holes 122 are supplied into the chamber 16 in a spray-like manner. The mass flow controllers 112, 113 and the on-off valves V1, V2 can control the flow rates through the gas supply pipes 114, 115. An exhaust device 13 is provided at the outlet 17. The venting means 13 can draw gas from within the chamber 16 to control the interior of the chamber 16 to a specified pressure.

The carrier 18 includes an insulating inner wall 181, an insulating spacer 182, a support 183, and a substrate 184. The substrate 184 is made of a conductive metal such as aluminum, and the carrier 18 has a function as a lower electrode. The stage 18 supports the support table 183 as a conductor by an insulating spacer 182. Further, a cylindrical insulating inner wall 181 made of, for example, quartz or the like is provided to surround the periphery of the stage 18. The carrier 19 is used to carry the sheet to be processed (e.g., the reticle to be fabricated). The material of the carrier 19 is typically a plasma resistant material such as ceramic, thereby preventing particles from being generated from the carrier 19.

Further, the plasma processing apparatus 1 includes a transport mechanism that feeds the sheet into the chamber 16 and places it on the carrier 19. After the plasma treatment of the sheet is completed, the handling mechanism removes the sheet from the carrier 19 in the chamber 16 to the outside of the chamber 16. The transport process of the transport mechanism does not require the operation of the plasma processing apparatus 1 to be stopped, nor the opening of the chamber 16.

In step S1, the transport mechanism feeds a sacrificial sheet 3 into the chamber 16 and places it on the carrier 19 of Figs. 2A and 2B. In the present embodiment, the sacrificial sheet 3 is an unprocessed reticle sheet, such as a quartz sheet, and the material mainly comprises cerium oxide (SiO ₂ ). A carrier 19 for electrostatically adsorbing the sacrificial sheet 3 is provided on the upper surface of the stage 18. The carrier 19 includes an electrode 192 and an insulating portion 191. The electrode 192 is disposed inside the insulating portion 191, and the electrode 192 is connected to the DC power source 6. A DC voltage is applied to the electrode 192 through the DC power source 6, and the electrode 192 adsorbs static electricity by Coulomb force to cause the carrier 19 to adsorb the sacrificial plate 3.

Next, in step S2, gas is introduced into the chamber 16 from the processing gas supply source 111, and plasma is supplied to the upper electrode (i.e., the spray structure 12) and the lower electrode (the carrier 18) to generate the plasma 2. In the present embodiment, the introduced gas is oxygen and chlorine, and the plasma 2 contains oxygen and chlorine, and different gases can be injected through the gas supply pipes 114 and 115, respectively.

The substrate 184 of the carrier 18 is connected to a first AC power source 82a via a first matching unit 81a. In addition, the substrate 184 of the carrier 18 is connected to a second AC power source 82b via a second matching unit 81b. The first AC power source 82a is a power source for generating plasma, and supplies a predetermined frequency (for example, 100 MHz) from the first AC power source 82a to the substrate 184 of the stage 18. High frequency power. Further, the second AC power source 82b is a power source for attracting ions (for bias voltage), and supplies a predetermined frequency (for example, 13 MHz) lower than the frequency of the first AC power source 82a from the second AC power source 82b to the substrate 184 of the stage 18. High frequency power.

Further, the spray structure 12 simultaneously functions as an upper electrode, and the spray structure 12 and the stage 18 function as a pair of electrodes (upper and lower electrodes). The spray structure 12 is electrically coupled to a variable DC power source 73 via a low pass filter (LPF) 71. The variable DC power source 73 can control the power supply or stop the power supply by means of a switch 72. Further, as will be described later, when high frequency power is applied from the first alternating current power source 81a and the second alternating current power source 81b to the stage 18 to generate plasma in the processing space, the switch 72 is turned on to be the upper electrode. The spray structure 12 applies a predetermined DC voltage.

Next, in step S3, the plasma 2 and the sacrificial sheet 3 are reacted to produce a product. In the present embodiment, the reaction of the plasma 2 with the sacrificial sheet 3 is as follows: (1): SiO ₂ + 2C + 2Cl ₂ -> SiCl ₄ + 2CO (1)

In the reaction of the formula (1), cerium oxide (SiO ₂ ) is derived from the sacrificial sheet 3; the source of carbon (C) is a carbon-containing member in the plasma processing apparatus 1, such as an insulating member, a plastic; chlorine (Cl) ₂ ) is from the plasma 2. The product produced by this reaction is gaseous ruthenium tetrachloride (SiCl ₄ ).

Then, referring to FIG. 2C, in step S4, the product reacted by the formula (1) is further reacted with the plasma 2, thereby forming a protective film 142 on the inner wall surface, for example, the wall surface 141 of the deposit shielding structure 14, or The inner wall of the chamber 16. The reaction of the product of the reaction of the formula (1) with the plasma 2 is as follows: (SiC) ₄ + O ₂ -> SiO ₂ + ₂ Cl ₂ (2)

In the reaction of the formula (2), gaseous ruthenium tetrachloride (SiCl ₄ ) is a product derived from the above reaction formula (1); oxygen (O ₂ ) is derived from the plasma 2. The cerium oxide (SiO ₂ ) produced by the reaction of the formula (2) is formed on the inner wall of the chamber 16 or on the wall surface of the separately disposed deposit shielding structure as a protective film. In the present embodiment, the cerium oxide (SiO ₂ ) produced by the reaction is formed on the wall surface 141 of the deposit shielding structure 14 which is additionally provided as the protective film 142. In order to allow the protective film 142 to be stably maintained on the wall surface 141, the protective film 142 should not be too thick. In the present embodiment, the thickness of the protective film 142 is preferably 250 nm or less. At a preferable thickness, the protective film 142 does not easily fall off from the wall surface 141, and the protective film 142 also prevents the reaction of the plasma 2 with the wall surface 141.

After the protective film 142 is formed on the wall surface 141, the conventional processing of the sheet to be processed can be performed. In this embodiment, the sheet to be processed is a reticle in production, and the material thereof mainly contains cerium oxide (SiO ₂ ). Conventional plasma processing is dry etching, and the gas used for dry etching is still oxygen and chlorine. After the reticle in production is dry etched, a specified design pattern is formed on the reticle.

3A-3C are schematic diagrams showing the reduction of the thickness of the protective film 142 by conventional plasma processing in an embodiment, wherein step S5 of FIG. 1 is described in conjunction with FIGS. 3A-3C.

Referring to FIGS. 3A and 3B, the transport mechanism feeds a sheet 4 to be processed into the chamber 16 and places it on the carrier 19. Then, the reaction gas is introduced into the chamber 16 from the processing gas supply source 111, and the plasma 2 is generated after the voltage is supplied to the upper electrode (spraying structure 12) and the lower electrode (the carrying stage 18). In the present embodiment, the gas for the reaction is the same as the gas in the above step S2, and both are oxygen and chlorine.

In this embodiment, the material to be processed 4 includes a substrate and a pattern layer. The pattern layer is disposed on the surface of the substrate. The material of the pattern layer is, for example, chromium (Cr) or photoresist, and the substrate is, for example, a quartz material. Cerium oxide (SiO ₂ ), the portion of the substrate not covered by the patterned layer is etched by the plasma 2. In step S5, after the plasma treatment of the sheet 4 to be processed using the plasma 2, the pattern of the pattern layer is transferred to the substrate.

Since the material of the protective film 142 and the sacrificial plate 3 is cerium oxide (SiO ₂ ), the protective film 142 and the plasma 2 also generate the same reaction as the above formula (1) during the conventional plasma treatment. After the conventional plasma treatment of the plurality of sheets 4 to be processed or a period of time, the protective film 142 of FIG. 3A is gradually thinned to a protective film 142a as shown in FIG. 3C by the reaction of the formula (1). The protective film 142a needs to be thickened to maintain a preferred thickness.

4A to 4C are schematic views showing the maintenance of the protective film 142 at a stable thickness in the plasma treatment of an embodiment, wherein steps S5 to S7 of FIG. 1 are described with reference to FIGS. 4A to 4C.

Referring to FIG. 4A and FIG. 4B, in step S6, a supplementary plate 5 containing cerium oxide is supplied into the chamber 16 by a transport mechanism. In the present embodiment, the supplementary sheet 5 is similar to the sacrificial sheet 3. The main material is cerium oxide, and the gas used for the reaction is still oxygen and chlorine.

The supplementary sheet 5 includes a plasma resistant film 51 and a substrate 52, and the plasma resistant film 51 The material is, for example, ceramic, and the substrate 52 is, for example, a quartz plate, and its material is cerium oxide. The substrate 52 has an exposed area 521 and a covered area 522. The plasma resistant film 51 covers the covered area 522 over a large area to prevent the covered area 522 from reacting with the plasma 2 and allows the exposed area 521 to react with the plasma 2.

In step S7, since the material of the substrate 51 and the sacrificial plate 3 are both cerium oxide, the gas used for the reaction is also oxygen and chlorine, and the exposed region 521 of the substrate 51 and the plasma 2 also undergo the reaction of the above formula (1). This reaction produces the same product as step S3, that is, gaseous ruthenium tetrachloride (SiCl ₄ ).

Next, in step S8, the product of the reaction of the formula (1) and the plasma 2 are further subjected to the reaction of the above formula (2). Similarly to the foregoing step S4, the product of the reaction of the formula (2) is formed at the wall surface 141, that is, formed on the protective film 142a, and therefore, the protective film 142a is thickened to become the protective film 142b as shown in Fig. 4C. Maintained at this stable thickness.

Since only a partial region (exposed region 521) of the substrate 51 reacts with the plasma 2, the amount of the cerium oxide participating in the reaction of the above formula (1) can be controlled by adjusting the size of the exposed region 521. In addition, it is understood from the formulas (1) and (2) that the amount of the product of the formula (2) (cerium oxide) depends on the amount of the product (barium tetrachloride) in the formula (1), and therefore, the protective film The increased thickness of 142a depends on the area of exposed area 521. The area of the exposed region 521 can be appropriately determined according to the difference between the thickness of the protective film 142a and the stable thickness, thereby supplementing the sufficient but not excessive amount of cerium oxide to participate in the reaction of the formula (1), thereby generating an appropriate amount by the formula (2). The cerium oxide thickens the protective film 142a to a stable thickness at the wall surface 141.

After the protective film 142b is maintained at a stable thickness, the supplementary sheet 5 is removed from the chamber 16 by the transport mechanism. Then, the process method can continue the plasma processing of the other material to be processed 4 by performing the above steps (FIG. S5) of FIG. 3A to FIG. 3C.

In summary, in the plasma processing method, the sacrificial plate and the supplementary plate can be fed into or removed from the chamber by the existing conveying mechanism of the plasma processing device, thereby forming or supplementing the protective film. The material can be simply fed into the chamber without the need to stop the operation of the plasma processing equipment or open the chamber. In addition, the protective film of a stable thickness prevents particles from being generated from the wall surface or from the protective film itself, and the chamber of the plasma processing apparatus is thus kept clean, and the time required to clean the chamber is also prolonged, that is, the plasma processing apparatus is stopped and opened. Chamber clearing The number of cleanliness can be reduced. Therefore, the plasma processing apparatus can continue the operation of the conventional plasma processing as much as possible, and maintain the state of manufacturing production instead of the maintenance shutdown state.

In addition, the supplementary sheet for supplementing the thickness of the protective film can be produced by using a mask substrate, and does not require an additional type of material substrate, so that it has the advantages of simple fabrication and low cost. Furthermore, the area of the exposed area of the supplementary sheet may be appropriately determined by the difference between the thickness of the thinned protective film and the stable thickness, thereby supplementing the sufficient but not excessive amount of cerium oxide to participate in the reaction in the chamber, thereby generating an appropriate amount. The cerium oxide is applied to the wall surface to thicken the protective film to a stable thickness.

The above is intended to be illustrative only and not limiting. Any equivalent modifications or alterations to the spirit and scope of the invention are intended to be included in the scope of the appended claims.

1‧‧‧Pulp processing equipment

11‧‧‧Processing gas supply device

111‧‧‧Processing gas supply

112, 113‧‧‧ mass flow controller

114, 115‧‧‧ gas supply piping

12‧‧‧Spray structure

121‧‧‧Gas diffusion chamber

122‧‧‧Dissipating holes

123‧‧‧Upper board

13‧‧‧Exhaust device

14‧‧‧Sediment shelter structure

141‧‧‧ wall

16‧‧‧ chamber

17‧‧‧Export

18‧‧‧Loading station

181‧‧‧Insulated inner wall

182‧‧‧Insulation partition

183‧‧‧Support table

184‧‧‧Substrate

19‧‧‧ Carrier Board

191‧‧‧Insulation

192‧‧‧electrode

2‧‧‧ Plasma

3‧‧‧ sacrificial plates

6‧‧‧DC power supply

71‧‧‧ low pass filter

72‧‧‧ switch

73‧‧‧Variable DC power supply

81a‧‧‧First matcher

81b‧‧‧Second matcher

82a‧‧‧First AC power supply

82b‧‧‧second AC power supply

V1, V2‧‧‧ opening and closing valve

Claims (10)

A process for plasma processing, comprising: providing a sacrificial plate containing cerium oxide into a chamber; generating a plasma containing oxygen and chlorine in the chamber; by the plasma and the sacrifice The reaction of the sheet produces a product; and a reaction of the product with the plasma forms a protective film on a wall inside the chamber. The process of claim 1, wherein the product is barium tetrachloride, the material of the protective film is ceria, and the reaction between the plasma and the sacrificial plate is as shown in the following formula (1). The reaction of the product with the plasma is as shown in the following formula (2): SiO ₂ + _{2 C} + ₂ Cl ₂ -> SiCl ₄ + 2 CO Formula (1) SiCl ₄ + O ₂ -> SiO ₂ + ₂ Cl ₂ Formula (2). The process of claim 1, wherein the sacrificial sheet is an unprocessed reticle substrate. The process of claim 1, further comprising: performing a plasma treatment on the at least one sheet to be processed using the plasma; and maintaining the protective film at a stable thickness after the plasma treatment. The process of claim 4, wherein the plasma treatment causes a reduction in thickness of the protective film. The process of claim 4, wherein the step of maintaining the protective film at the stable thickness comprises: providing a supplementary plate containing cerium oxide into the chamber; by using the plasma and the supplementary plate The reaction produces the product; and the protective film is thickened by the reaction of the product with the plasma to maintain the stable thickness. The process of claim 6, wherein the supplementary sheet material comprises a substrate and a plasma resistant film, wherein the substrate has an exposed area and a covering area and contains cerium oxide, wherein the anti-plasma film Covering the coverage area over a large area to prevent the coverage area from reacting with the plasma, and allowing the exposed area to react with the plasma. The anti-plasma film is made of ceramic, wherein the thickness of the protective film is increased. It depends on the area of the exposed area. The process method of claim 4, wherein the sacrificial sheet, the sheet to be processed, and the supplementary sheet have substrates of the same material. The method of claim 4, wherein the stable thickness is 250 nm or less. A reticle sheet for use in a process according to any one of claims 4 to 9, comprising: a substrate having an exposed area and a covering area, the substrate containing cerium oxide; and an anti-electricity The plasma film covers the covering area over a large area to prevent the covering area from reacting with the plasma, and allows the exposed area to react with the plasma, wherein the increased thickness of the protective film depends on the area of the exposed area.