JP2010156009A - Method for forming thermal spray coating in plasma etching apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress foreign matters from splashing due to a thermal spraying material from an inner wall of a processing chamber for executing the processing such as the etching to a semiconductor device. <P>SOLUTION: In the method for forming a thermal spray coating, by which the thermal spray coating is formed by using a thermal spraying machine on a component in contact with plasma in a vacuum processing chamber in a plasma etching apparatus for generating plasma by supplying the high frequency energy to raw gas introduced inside the vacuum processing chamber, and executing the plasma etching to a material arranged inside the vacuum processing chamber, the thermal spraying machine has a thermal spraying machine body 107 which heats and melts a thermal spraying material by a thermal spraying flame, and sprays it on an objective covering surface, and a blocking plate 109 arranged between the body and the objective covering surface 111. Thermal spraying particles flying to the objective covering surface along the flow of an outer peripheral part of the thermal spraying flame are blocked by the blocking plate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for forming a sprayed film, and more particularly, to a technique for forming a sprayed film by using a thermal spraying machine at a portion in contact with plasma in a vacuum processing chamber constituting a plasma etching apparatus.

Generally, in manufacturing processes such as semiconductor devices and liquid crystal devices, the use of fluoride, such as SF ₆ or CF ₄ in the etching treatment chamber, chlorides such as BC1 ₃ or SiCl _4, a process gas including bromide such as HBr Therefore, the inner wall material of the etching process vessel is significantly corroded.

For example, as a material used for the inner wall of the plasma processing container of a semiconductor manufacturing apparatus, a metal material such as Al, Al alloy or stainless steel is used as a base material, and the surface thereof is made of Al anodized film, boron carbide, alumina or the like. A thermal sprayed film or a film coated with a material such as SiO ₂ or SiC, or a film coated with a polymer film such as a fluorine resin or an epoxy resin is used.

When these materials come into contact with highly corrosive halogen ions, they are chemically damaged and produce fine particles such as SiO ₂ and A 1 ₂ O ₃ . In addition, erosion damage may be caused by ions excited by plasma.

In particular, in an etching process using a gas of a halogen compound, plasma is often used in order to further activate the reaction. However, in a plasma environment, the halogen compound dissociates and generates very strong corrosive atomic F, Cl, Br and the like. At this time, if fine powdered solids (fine particles) such as SiO ₂ and Al ₂ O ₃ are present in the environment, the member used in the plasma processing vessel is subjected to chemical corrosion and erosion damage due to the fine particles. The so-called erosion / corrosion action is strongly received. In addition, in an environment in which plasma is excited in the etching chamber, a non-corrosive gas such as Ar gas is ionized and a phenomenon (ion bombardment) that strongly collides with the solid surface occurs. For this reason, the various members arranged in the container are more strongly damaged.

In order to improve the plasma resistance, it is known to cover the surface of the etching chamber with a sprayed film such as Y ₂ O ₃ having a porosity of 5% to 10% (see Patent Document 1). In this method, since the surface of the etching chamber that is in contact with the plasma is coated with a sprayed film such as Y ₂ O ₃ , it can be expected that damage caused by the plasma is reduced. In addition, the metal film of 50-500 micrometers is used for the undercoat which coat | covers the base-material surface, and it considers that the sprayed film adheres regarding the roughness of the base-material surface which coat | covers the surface with a sprayed film.
JP 2001-164354 A

  When plasma is actually generated in the etching chamber manufactured by the conventional surface treatment method, fine foreign matter adhering to the surface of the sprayed coating is released into the plasma by the generated plasma and deposited on the wafer. It causes defects in semiconductor devices.

  An unmelted thermal spray material may adhere to the surface of the thermal spray film in the etching chamber that comes into contact with the plasma as a foreign matter. Further, a completely melted thermal spray material may adhere to the surface of the thermal spray coating.

  Since these foreign substances have weak adhesion even if they adhere to the surface of the sprayed film, they are detached from the surface of the sprayed film only by contacting the plasma and scattered in the plasma. As a result, the contamination mainly composed of fine particles of chemical components resulting from the sprayed coating material increases in the etching chamber.

As described above, in the conventional technique, the problem that the number of minute foreign matters due to the sprayed film material made of a ceramic material such as A1 ₂ O ₃ or Y ₂ O ₃ covering the surface of a part used in the etching process chamber increases. Are not fully considered.

The parts used in the etching processing chamber and coated with a sprayed film are attached to the etching processing apparatus after being cleaned. When cleaning parts, it is common to combine cleaning by applying ultrasonic waves while immersed in a solution, cleaning by spraying H ₂ O or CO _2, cleaning by immersing in a solvent or pure water, etc. In addition, it is difficult to remove all the minute foreign substances made of the material of the sprayed film existing in the sprayed film.

  In many cases, the fine foreign matter made of the material used for the sprayed film is caused by the spraying process itself for manufacturing the sprayed part. For example, during the process of spraying the thermal spray material from the thermal spraying device to the thermal spray component, depending on the particle size of the base particles used, the thermal spray material may reach the thermal spray surface in a solidified state after being completely melted in the thermal spray frame. There are cases where the sprayed surface reaches the sprayed surface without entering the frame. When constructing a normal thermal spraying process, the conditions for melting particles of a specific particle size to reach the surface to be sprayed are selected. There will be molten particles.

  In other words, when the particle actually used is larger than the optimum particle, only the vicinity of the surface of the sprayed particle reaches the sprayed surface in the melted state, and when smaller than the optimum particle, the spraying is performed before entering the high temperature region at the center of the spray frame. Riding on the frame will reach the sprayed surface. When particles smaller than the optimum particles enter the thermal spray frame, the thermal spray particles reach the sprayed surface after being completely melted and then solidified in the scattering process. As a result, when these giant sprayed particles or fine particles reach the sprayed surface, the adhesion force with the sprayed film is small.

  When a part whose surface is coated with such a low-adhesion thermal spray material is brought into contact with plasma in the etching chamber or exposed to an inert gas such as Ar, a minute foreign substance made of the thermal spray material adhered to the surface Are scattered in the plasma and reach the wafer on which the semiconductor device or the like is made. The foreign matter that has reached the wafer causes pattern defects that cause poor wiring and electrical characteristics of the semiconductor device, and significantly reduces the productivity of the semiconductor device.

  The present invention has been made in view of such problems, and is a surface treatment technique capable of suppressing the scattering of foreign matters caused by a thermal spray material from the inner wall of a processing chamber that performs processing such as etching on a semiconductor device. Is to provide.

  In order to solve the above problems, the present invention employs the following means.

  A component in contact with the plasma in the vacuum processing chamber in a plasma etching apparatus for generating plasma by supplying high-frequency energy to the processing gas introduced into the vacuum processing chamber and performing plasma etching on a sample disposed in the vacuum processing chamber In the method for forming a thermal spray film using a thermal spraying machine, the thermal spraying machine includes a thermal spraying machine body that heats and melts a thermal spraying material by a thermal spraying frame and sprays it on a coating target surface, and between the main body and the coating target surface. A shielding plate disposed on the surface of the thermal spraying frame is shielded by the shielding plate along the flow around the outer periphery of the thermal spraying frame.

  Since the present invention has the above-described configuration, it is possible to suppress scattering of foreign matters caused by the thermal spray material from the inner wall of a processing chamber that performs processing such as etching on a semiconductor device.

  Hereinafter, the best embodiment will be described with reference to the accompanying drawings. FIG. 1 is a diagram for explaining the configuration of a thermal sprayer main body used in the present embodiment.

  As shown in FIG. 1, a thermal sprayer main body 107 includes a thermal sprayer base 106, an electrode (cathode) 101 having a protrusion attached to the thermal sprayer base 106, a cylindrical electrode (anode) 102, and the base. For example, a cylindrical insulating cylinder 108 that insulates 106 (electrode 101) and the cylindrical electrode 102 and couples them is provided.

  The insulating cylinder 108 is provided with a gas supply pipe 103, and a process gas such as Ar gas is supplied from a gas supply source (not shown). The cylindrical anode 102 includes a thermal spray material supply pipe 104, and supplies a thermal spray material such as ceramics through the supply pipe.

  When a sprayed film is formed on the component to be sprayed 112, a plasma discharge is generated by applying a voltage between the cathode 101 and the anode 102 while supplying a process gas such as Ar from the gas supply pipe 103. The process gas is turned into plasma by the energy of the plasma discharge to generate the thermal spray frame 105. Further, a thermal spray material (powder) such as ceramics is injected into the thermal spray frame 105 through the supply pipe 103. The injected thermal spray material is melted in the thermal spray frame, and in this state, reaches the thermal spray component 112 and forms the thermal spray film 111 on the surface of the thermal spray component.

As the process gas, a gas such as He, H ₂ , or O ₂ can be used in addition to Ar. As the spray _{material, Al 2 O 3, YAG,} Y 2 O 3, Gd 2 O 3, Yb 2 O 3, it is possible to use a material containing any one or more of YF _3.

  As described above, by supplying the thermal spray material from the thermal spray material supply pipe 104, it is possible to generate the thermal spray material melted in the thermal spray frame 105 discharged from the thermal sprayer main body 107 to the thermal spray component 112 side. As a result, the sprayed film 111 is formed on the surface of the component to be sprayed 112.

  When the sprayed film 111 is formed with such a spraying apparatus, fine particles made of a sprayed material may adhere to the surface of the sprayed film 111. That is, a part of the thermal spray material supplied from the thermal spray material supply pipe 104 may not enter the thermal spray frame 105 and may reach the thermal spray film 111 through the outermost periphery of the thermal spray frame 105. In this case, fine foreign matter adheres to the surface of the sprayed film 111 formed on the component to be sprayed 112 in a solidified state.

  In the case where a sprayed part having such a fine foreign substance attached to the surface of the sprayed film is used in an etching apparatus, the fine foreign substance is released into the plasma during the plasma process. The minute foreign matter released into the plasma is deposited on a wafer for manufacturing a semiconductor device, and causes a defect in the device, which significantly reduces the productivity of the semiconductor device.

  FIG. 2 is a diagram for explaining the configuration of the thermal spraying apparatus used in the present embodiment. 2 that are the same as those shown in FIG. 1 are given the same reference numerals, and descriptions thereof are omitted.

  In this embodiment, when performing thermal spraying using the thermal sprayer shown in FIG. 1, the shielding plate 109 is disposed in the middle of the thermal spray frame 105 generated between the thermal sprayer main body 106 and the thermal sprayed component 112. The shielding plate 109 is provided with a through hole 13 that shields the outer peripheral portion of the spray frame and allows only the inner peripheral portion to pass therethrough.

  As described above, when the shielding plate 109 is disposed in the middle of the thermal spray frame, the unmelted or once melted and solidified thermal spray particles flying to the thermal sprayed part 112 along the flow of the outer peripheral portion of the thermal spray frame 105 are shielded plate 109. This prevents the sprayed component 112 from flying.

  The shielding plate 109 needs to be formed of, for example, a ceramic material having a melting point higher than that of the thermal spray material used in the thermal spraying process. Thereby, the quantity of the micro foreign material adhering to the sprayed film 111 surface formed in the to-be-sprayed component 112 can be suppressed.

  In the present embodiment, when forming the sprayed film in the atmosphere, a ceramic shielding plate having the same composition as the sprayed material is used to cut the outer peripheral portion of the sprayed frame released from the sprayer. By this shielding plate, it is possible to suppress the scattering amount of the fine particles of the sprayed material that does not completely enter the spray frame and scatters on the part to be sprayed.

  In addition, by controlling the particle size distribution of the thermal spray material, that is, by removing the fine thermal spray material powder or the huge thermal spray powder in advance, it is possible to reduce the minute foreign matter adhering to the surface of the thermal spray film 111. It is desirable that the particle size of the thermal spray material is, for example, within the center particle size of ± 20%.

  When the particle size is small, it can be dealt with by shortening the spraying distance. In this case, however, the large particle size spray material must be removed. On the contrary, when the particle size of the thermal spray material is large, it can be dealt with by increasing the output of the thermal spray frame. However, in this case, the spray material with a small particle size must be removed.

  As shown in the present embodiment, by providing a shielding plate on the outer peripheral portion of the thermal spray frame, it is possible to reduce the minute foreign matter adhering to the surface of the component whose surface is coated by thermal spraying. As a result, even when the surface of the sprayed film comes into contact with plasma in the etching process, fine foreign matters (0.1 μm to 1.0 μm) due to the sprayed film material are not generated from the sprayed film.

  As described above, in the spraying process of the sprayed film, by spraying the spray material into the spray frame, the spray material reaches the part to be sprayed in a molten state. The thermal spray material flying in the molten state is deposited on the component to be sprayed to form a thermal spray film having a thickness of about 50 to 500 μm. When the thermal spray material is injected into the thermal spray frame, if the particle size of the thermal spray material is very small and cannot enter the thermal spray frame, the thermal spray material is transported to the thermal spray component along the gas flow at the outer periphery of the thermal spray frame. In this case, the thermal spray material adheres to the surface of the component to be sprayed in an unmelted state. Further, even a fine spray material powder may enter the spray frame. In this case, since the particle size is small, it does not reach the center of the thermal spray frame. As a result, although the particles of the thermal spray material melt, they are transported to the thermal sprayed part along the flow around the outer periphery of the thermal spray frame, so the particles themselves are cooled and solidified during the time from the thermal spraying device to the thermal sprayed part. End up. As a result, the spray particles when reaching the part to be sprayed are not in a molten state. For this reason, the contact | adhesion power of a to-be-sprayed component and a thermal spray material particle will be in the state with few.

  In this embodiment, in order to remove particles that are present on the outer periphery of the thermal spray frame and solidify before reaching the thermal sprayed part even if it is not melted or melted, the surface of the thermal sprayed part has an adhesive force. Adhesion of weak spray material particles can be suppressed.

  As described above, according to the present embodiment, the surface treatment of the etching apparatus parts is performed using the thermal spraying machine in which the shielding plate 109 is disposed in the middle of the thermal spray frame 105, and the unmelted portion present on the outer peripheral portion of the thermal spray frame. Alternatively, particles that solidify before reaching the sprayed part even after melting are removed. For this reason, the foreign material resulting from the thermal spray material does not adhere to the surface of the thermal spray film formed on the surface of the component to be sprayed.

  As a result, in a plasma process in which a thermal sprayed part is attached to an etching processing apparatus and a semiconductor device or the like is manufactured, even if the sprayed film comes into contact with the plasma, a minute foreign matter due to the sprayed film material is generated from the sprayed film. Thus, the foreign material caused by the thermal spray material does not fly on the wafer subjected to the processing such as etching to manufacture the semiconductor device, and a semiconductor device with few defects due to the foreign material and contamination caused by the foreign material can be produced.

It is a figure explaining the structure of the thermal sprayer main body used by this embodiment. It is a figure explaining the structure of the thermal spraying apparatus used by this embodiment.

Explanation of symbols

101 electrode (cathode)
102 Electrode (Anode)
Reference Signs List 103 Gas introduction pipe 104 Thermal spray material supply pipe 105 Thermal spray frame 106 Base 107 Thermal spray machine body 108 Insulating cylinder 109 Shield plate 111 Thermal spray film 112 Thermal sprayed part 113 Through hole

Claims (4)

A component in contact with the plasma in the vacuum processing chamber in a plasma etching apparatus for generating plasma by supplying high-frequency energy to the processing gas introduced into the vacuum processing chamber and performing plasma etching on a sample disposed in the vacuum processing chamber In the method for forming a sprayed film using a thermal spraying machine,
The thermal spraying machine includes a thermal spraying machine main body that heats and melts a thermal spray material by a thermal spraying frame and sprays it on a surface to be coated, and a shielding plate disposed between the main body and the surface to be coated. A method for forming a sprayed film in a plasma etching apparatus, wherein sprayed particles flying along the surface to be coated are shielded. In the formation method of the sprayed film of Claim 1,
The method for forming a thermal spray film in a plasma etching apparatus, wherein the thermal spray material includes at least one of Al ₂ O ₃ , YAG, Y ₂ O ₃ , Gd ₂ O ₃ , Yb ₂ O ₃ , and YF ₃ . In the formation method of the sprayed film of Claim 1,
A method of forming a sprayed film in a plasma etching apparatus, characterized in that the particle size of the sprayed material is set to a particle size within a center particle size of ± 20%. A component in contact with the plasma in the vacuum processing chamber in a plasma etching apparatus for generating plasma by supplying high-frequency energy to the processing gas introduced into the vacuum processing chamber and performing plasma etching on a sample disposed in the vacuum processing chamber In addition, in the thermal spray film forming apparatus for forming the thermal spray film,
A thermal spraying machine main body that forms a thermal spraying frame that heats and melts the thermal spraying material and sprays it on the surface to be coated; and a thermal spraying machine that includes a shielding plate disposed between the main body and the surface to be coated. A thermal spray film in a plasma etching apparatus is characterized in that a thermal spray film is formed on the coating target surface by shielding spray particles flying to a portion of the vacuum processing chamber which is a coating target surface in contact with the plasma along the flow. Forming equipment.

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