JP3675065B2 - Dry etching method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  This inventionDoFor example, gate electrode materials and silicon oxide (SiO₂) It is suitable for application to film etching.
[0002]
[Prior art]
In dry etching, it is well known that the plasma etching process cannot ignore the interaction with the wall, and in particular the transport of deposits into the wall into the bulk plasma has a significant effect on the process. . For example, in the processing of a gate electrode material such as polycrystalline silicon (Si), SiCl which is a reaction product at the time of etching_xIs deposited on the inner wall of the chamber (etching chamber), and this is released when the plasma comes into contact with the wall, affecting the reproducibility of etching and the like.
[0003]
Specifically, after the inside of the chamber is plasma-cleaned after completion of etching, an actual gas discharge called so-called seasoning is performed in order to return the inside of the chamber in the cleaning atmosphere to the actual gas atmosphere. At this time, the deposit deposited on the inner wall of the chamber is released during the etching, and the deposit deposited excessively on the inner wall of the chamber affects the reproducibility of the etching.
[0004]
This phenomenon is not limited to the processing of the gate electrode material.₂The same applies when the film is etched. That is, this SiO₂In film etching, fluorocarbon polymer-based gas is used, but fluorocarbon polymer precursors, which are the key to ensuring selectivity, are deposited on the inner wall of the chamber, etc., and come into contact with the plasma, which is released into the plasma and discharged. The C / F ratio at the time is upset, causing serious problems such as etching stopping when forming fine contact holes.
[0005]
[Problems to be solved by the invention]
From the above, a dry etching method capable of satisfactorily controlling the influence on the wall at the time of etching is indispensable for a future microfabrication process, and its practical application is eagerly desired.
[0006]
  Therefore, the object of the present invention is to control the amount of reaction products and polymer precursors deposited on the inner wall of the etching chamber during etching, without causing pattern thickening, etching stop, and high taper. , Gate electrode materials such as polycrystalline Si and SiO with high selectivity₂Films can be etched with high accuracy and good reproducibility, and fine contact holes can be easily formed with fine patterns and high aspect ratios.DoIt is to provide a lie etching method.
[0007]
[Means for Solving the Problems]
As a result of diligent studies to solve the above-described problems of the prior art, the present inventor has found a means for solving the above-described problems by controlling the amount of radicals during discharge by means other than discharge parameters. The outline will be described below.
As described above, in the dry etching apparatus, the influence on the plasma etching process due to the interaction between the plasma and the inner wall of the chamber is very large. In particular, it is well known that deposits deposited on the inner wall of the chamber are adversely affected by the plasma etching process by being released into the bulk plasma. Therefore, if the interaction between the chamber inner wall and the plasma is positively controlled, the amount of deposits on the chamber inner wall can be effectively controlled. Specifically, if the chamber inner wall is cooled to a low temperature of 0 ° C. or lower, the amount of deposits adsorbed on the chamber inner wall increases, and conversely, if the chamber inner wall is heated to a high temperature, deposits are released from the chamber inner wall. Thus, the amount of deposits deposited on the inner wall is reduced. Therefore, in a dry etching apparatus that performs etching using plasma, if the temperature of the chamber inner wall can be changed rapidly, the adsorption of deposits to the chamber inner wall and the chamber inner wall from the chamber inner wall can be performed between the etching steps. The release of the deposit can be quickly controlled, and the density of the deposited species in the plasma can be controlled accordingly. For this purpose, it is effective to provide a mechanism for rapidly controlling the temperature of the inner wall of the chamber.
[0008]
Generally, in a dry etching apparatus, the inner wall of the chamber is made of a metal such as stainless steel, and a reflector or sleeve is installed on the surface of the chamber to prevent contamination by the metal from the inner wall. Since the temperature of the sleeve itself is not controlled, the temperature control of the inner wall of the chamber is insufficient even when the heater is wound around the outer wall of the chamber and heated.
[0009]
According to the knowledge of the present inventor, rapid temperature control of the inner wall of the chamber can be easily performed by installing a ceramic cover with a built-in heater on the inner wall of the chamber and improving the thermal conductivity between them. Specifically, for example, a gas refrigerant chiller for supplying a gas refrigerant to a refrigerant flow path in a chamber wall made of stainless steel or the like is connected, and aluminum nitride ( A ceramic cover such as AlN (with a thermal conductivity of 0.235 cal / cm · s · ° C.) and a heater built in is directly joined by brazing. Here, since the gas refrigerant has a high flow velocity, the inner wall of the chamber can be cooled in a very short time. By directly brazing a cover made of ceramics such as AlN having good thermal conductivity directly to the inner wall of the chamber, the cooling effect is quickly transmitted to the cover. Furthermore, since a heater is built in a cover made of ceramics such as AlN, rapid heating can be easily performed by this heater.
The present invention has been devised based on the above studies.
[0010]
  That is, in order to achieve the above object, the present inventionIs,
  In a dry etching method in which an object to be etched is etched by just etching and subsequent overetching using a dry etching apparatus,
  When performing just etching, the inner wall of the side wall of the etching chamber of the dry etching apparatus was cooled to adsorb the reaction product on the surface, and the inner wall of the etching chamber was heated to release the reaction product from the surface. After over-etching
  It is characterized by this.
[0013]
  This inventionInTypically, the rate of temperature increase when heating the inner wall of the etching chamber is 50 ° C./min to 300 ° C./min, and the rate of temperature decrease when cooling the inner wall of the etching chamber is 50 ° C./min to 100 ° C./min.
[0014]
  Of this inventiononeIn an embodiment,Cooling the inner wall of the etching chamber by supplying the gas refrigerant to the refrigerant flow path provided on the inner wall of the etching chamber by the gas refrigerant supply device via the gas refrigerant supply pipe, or provided on the surface of the inner wall of the etching chamber. The inner wall of the etching chamber is heated by a heating mechanism comprising a coated body and a heating element provided inside the coated body..
[0015]
  This inventionInThe covering is preferably brazed to the inner wall of the etching chamber. Further, as the material of the covering, ceramics such as AlN having good thermal conductivity is preferably used.
[0016]
  This inventionofIn one embodiment, the dry etching apparatus has parallel plate type electrodes, and further includes rapid temperature control means for rapidly controlling the temperature of the counter electrode.
[0018]
  This inventionofIn a typical embodiment, the inner wall of the etching chamber is kept at a low temperature of 0 ° C. or lower during just etching, and the inner wall of the etching chamber is heated to a high temperature of 100 ° C. or higher during over-etching.
[0019]
In the present invention configured as described above, the temperature of the inner wall of the etching chamber can be rapidly controlled, so that reaction products and polymers generated during the etching can be adsorbed on the inner wall of the etching chamber, and positively generated therefrom. Therefore, pattern thickening due to excessive deposition of reaction products during etching in gate electrode material processing such as polycrystalline Si film can be prevented, and SiO 2₂Control of the C / F ratio in the bulk plasma during etching of a film or the like is facilitated, and dry etching with good reproducibility can be realized.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0021]
First, a dry etching apparatus according to the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing this dry etching apparatus.
As shown in FIG. 1, this dry etching apparatus is movable in a vertical direction provided in a diffusion chamber 1, a helicon wave plasma generation source provided in the upper portion of the diffusion chamber 1, and the diffusion chamber 1. A wafer mounting electrode (wafer stage) 2. A gas refrigerant chiller 3 for supplying a gas refrigerant to the side wall of the diffusion chamber 1 is provided outside the diffusion chamber 1. A gas discharge port 4 is provided at the lower part of the diffusion chamber 1 and is connected to an exhaust vacuum pump (not shown) provided outside so that the gas in the diffusion chamber 1 can be exhausted. It has become. Further, the diffusion chamber 1 is provided with an etching gas inlet and a gate valve (both not shown).
[0022]
The above-described helicon wave plasma generation source is configured as follows. That is, a cylindrical quartz bell jar 5 having a diameter of, for example, 350 mm is provided on the upper portion of the diffusion chamber 1, and an RF antenna 6 is provided in a loop shape on the outer peripheral portion of the cylindrical quartz bell jar 5. The RF antenna 6 has, for example, an antenna shape in which M = 1 mode plasma is generated. The RF antenna 6 is connected to the RF power source 8 via the matching network 7. A coil is wound twice around the outer periphery of the RF antenna 6, and a solenoid coil assembly 9 is composed of the inner peripheral coil 9 a and the outer peripheral coil 9 b. Here, the inner peripheral coil 9a contributes to the propagation of the helicon wave, and the outer peripheral coil 9b contributes to the transport of the generated plasma. The upper end portion of the cylindrical quartz bell jar 5 is covered with a top plate 10 made of a dielectric. An RF antenna 11 is installed in a loop shape on the top plate 10 and connected to an RF power source 13 via a matching network 12.
[0023]
The wafer installation electrode 2 provided inside the cylindrical quartz bell jar 5 has a mechanism (not shown) for moving in the vertical direction and an electrostatic chuck (not shown) for tightly fixing the wafer 14. doing. Further, a substrate bias power source 15 is connected to the wafer placement electrode 2 so that incident ion energy incident on the wafer 14 can be controlled. Further, a multipole magnet 16 is provided on the outer peripheral portion of the diffusion chamber 1 and around the wafer installation electrode 2, and a cusp magnetic field for suppressing the disappearance of electrons in contact with the wall is applied to the diffusion chamber 1. It can be formed inside.
[0024]
A chamber inner wall cover 17 made of ceramics having a good thermal conductivity and incorporating a heater (not shown) is directly brazed to the inner wall surface of the diffusion chamber 1. The chamber inner wall cover 17 is made of, for example, AlN. Specific examples of the brazing material used for the brazing include metals such as titanium (Ti), tin (Sn), antimony (Sb), and magnesium (Mg), and alloys thereof. It is usually used in the form of a multilayer film of metal or alloy. A side wall of the diffusion chamber 1 is connected to a gas refrigerant chiller 3 provided outside via a gas refrigerant pipe 18 and a gas refrigerant pipe 19. Then, a gas refrigerant such as chlorofluorocarbon is supplied from the gas refrigerant chiller 3 to a refrigerant flow path (not shown) provided in the wall of the diffusion chamber 1 through the gas refrigerant pipe 18, and the gas refrigerant is supplied through the gas refrigerant pipe 19. Return to chiller 3. Thereby, the side wall of the diffusion chamber 1 can be rapidly cooled. The gas refrigerant pipe 18 is provided with a cryogenic valve 20. Further, the gas refrigerant pipe 18 and the gas refrigerant pipe 19 on the upstream side of the cryogenic valve 20 are connected via a bypass pipe 22 provided with a bypass line cryogenic valve 21. The cryogenic valve 20 and the bypass line cryogenic valve 21 can control the flow rate of the gas refrigerant supplied from the gas refrigerant chiller 3 to the side wall of the diffusion chamber 1.
[0025]
According to the dry etching apparatus according to the first embodiment of the present invention configured as described above, the gas refrigerant chiller 3 is connected to the side wall of the diffusion chamber 1 to supply gas refrigerant such as chlorofluorocarbon, and the diffusion chamber. By directly brazing a chamber inner wall cover 17 made of ceramics such as AlN having good heat conductivity and having a built-in heater on the inner wall surface of 1, the side wall of the diffusion chamber 1 can be rapidly cooled and heated. it can. For this reason, by controlling the temperature of the inner wall of the diffusion chamber 1, it is possible to control the adsorption of the reaction product generated during the etching to the surface of the chamber inner wall cover 17 or the release from the reaction product. The adverse effect on the etching due to excessive deposition on the substrate can be suppressed.
[0026]
Next explained is a dry etching method according to the first embodiment of the invention. In the dry etching method according to the first embodiment, the gate electrode material is processed as follows using the dry etching apparatus shown in FIG. That is, first, as shown in FIG.₂The film 32, the polycrystalline Si film 33 doped with impurities, and tungsten silicide (WSi)_x) A film 34 is sequentially formed, and a resist pattern 35 is formed thereon. Thereafter, using this resist pattern 35 as a mask, etching is performed in two steps as follows to form a gate electrode.
[0027]
First, as the first step, WSi_xJust etching of the film 34 and the polycrystalline Si film 33 is performed. That is, first, a gas refrigerant of chlorofluorocarbon having a temperature of about −140 ° C., for example, is supplied from the gas refrigerant chiller 3 to the side wall of the chamber 1 to rapidly cool the chamber inner wall cover 17. The cooling rate at this time is, for example, 100 ° C./min. Next, using the resist pattern 35 as a mask, WSi_xThe film 34 and the polycrystalline Si film 33 are sequentially etched to form a gate electrode pattern having a W polycide structure. At this time, as shown in FIG. 2B, the etching is interrupted while leaving a part of the polycrystalline Si film 33 at the bottom of the portion to be etched. At this point, the first step ends. In this first step, just etching, for example, Cl is used as an etching gas.₂And O₂The gas flow rate is 50 sccm, 10 sccm, the pressure is 5 mTorr, the power supplied to the RF antennas 6 and 11 is 2500 W, the frequency is 13.56 MHz, the RF bias is 100 W, the substrate temperature is 20 ° C., and the wall surface The temperature is −50 ° C.
[0028]
Here, the SiCl during the just etching of the first step_xEtc. are produced. However, as described above, the temperature of the chamber inner wall cover 17 is as low as −50 ° C., and the temperature of the Si substrate 31 is 20 ° C., which is higher than that of the chamber inner wall cover 17._xMost of the reaction products such as are not deposited on the Si substrate 31 and are adsorbed on the surface of the chamber inner wall cover 17. For this reason, SiCl on the Si substrate 31_xJust etching can be performed without any trouble without causing the gate electrode pattern to be thickened due to excessive deposition of reaction products.
[0029]
Next, after closing the cryogenic valve 20 and the bypass line cryogenic valve 21, a heater (not shown) built in the chamber inner wall cover 17 is energized to generate heat, and the chamber inner wall cover 17 is moved from −50 ° C. Heat rapidly to 200 ° C. The heating rate at this time is, for example, about 200 ° C./min, and the heating time is, for example, about 75 seconds.
[0030]
By this rapid heating, for example, SiCl adsorbed on the chamber inner wall cover 17 during the just etching in the first step._xAnd the like are rapidly released into the cylindrical quartz bell jar 5.
[0031]
Next, overetching of the polycrystalline Si film 33 is performed as a second step. In the second step overetching, the etching of the portion of the polycrystalline Si film 33 left at the bottom of the portion etched in the first step just etching is performed as shown in FIG. 2C. SiO₂This is performed until the surface of the film 32 is exposed. In the second step of overetching, for example, Cl is used as an etching gas.₂And O₂The gas flow rate is 50 sccm and 10 sccm, the pressure is 5 mTorr, the power supplied to the RF antennas 6 and 11 is 2500 W, the frequency is 13.56 MHz, the RF bias is 20 W, and the substrate temperature is −30 ° C. The chamber wall temperature is 200 ° C.
[0032]
Here, in this over-etching of the second step, the SiCl adsorbed on the surface of the chamber inner wall cover 17._xThe reaction product such as the above is released in advance, and the temperature of the Si substrate 31 is lowered, so that the deposition of the reaction product on the surface of the chamber inner wall cover 17 can be suppressed. This also makes it possible to form a gate electrode having a good shape by etching with a high selectivity without causing a shape abnormality such as notching.
[0033]
As described above, according to the dry etching method of the first embodiment, the surface of the chamber inner wall cover 17 is maintained by keeping the chamber inner wall cover 17 at a low temperature of, for example, −50 ° C. during the just etching in the first step. SiCl_xSince the reaction product such as the above is adsorbed and then the chamber inner wall cover 17 is rapidly heated to release the reaction product therefrom, the second step overetching is performed. A fine gate electrode pattern can be easily formed without causing a thickening of the gate electrode pattern or abnormal shape due to excessive deposition of reaction products on the Si substrate 31 during just etching.
[0034]
Next explained is a dry etching apparatus according to the second embodiment of the invention. This dry etching apparatus is a plasma etching apparatus having parallel plate type electrodes. FIG. 3 is a schematic diagram showing this dry etching apparatus.
[0035]
As shown in FIG. 3, in this dry etching apparatus, a cathode 43 on which a wafer 42 is placed and an anode (opposite electrode) 44 opposite thereto are provided in a cylindrical chamber 41. The chamber 41 is provided with a gas discharge port 45 and is connected to an exhaust vacuum pump (not shown) provided outside so that the gas in the chamber 41 can be exhausted. Further, the chamber 41 is provided with an etching gas inlet and a gate valve (both not shown). The cathode 43 is electrically connected to a high frequency power supply 47 through a matching box 46. Further, the cathode 43 incorporates an electrostatic chuck (not shown), and is connected to a chiller (not shown) through a refrigerant pipe (not shown).
[0036]
A chamber inner wall cover 48 similar to that of the first embodiment is brazed directly to the inner wall of the chamber 41. A side wall of the chamber 41 is connected to a gas refrigerant chiller 51 provided outside via a gas refrigerant pipe 49 and a gas refrigerant pipe 50. A gas refrigerant such as chlorofluorocarbon is supplied from the gas refrigerant chiller 51 to a refrigerant flow path (not shown) provided in the side wall of the chamber 41 through the refrigerant pipe 49, and the gas refrigerant chiller 51 is supplied through the gas refrigerant pipe 50. It comes to return to. Thereby, the side wall of the chamber 41 can be rapidly cooled. The gas refrigerant pipe 49 is provided with an electronic control valve 52. Further, the gas refrigerant pipe 49 and the gas refrigerant pipe 50 on the upstream side of the electronic control valve 52 are connected via a bypass pipe 54 provided with an electronic control valve 53. The flow rate of the gas refrigerant supplied from the gas refrigerant chiller 51 to the side wall of the chamber 41 can be controlled by the electronic control valves 52 and 53.
[0037]
According to the dry etching apparatus according to the second embodiment configured as described above, the gas refrigerant chiller 51 is connected to the side wall of the chamber 41 to supply a gas refrigerant such as chlorofluorocarbon, and the inner wall of the chamber 41 is By directly brazing the chamber inner wall cover 48 made of ceramics such as AlN having good heat conductivity and having a heater built in the surface, the entire wall surface of the chamber 41 is cooled and heated in the same manner as in the first embodiment. Can be done rapidly. For this reason, the temperature control of the inner wall of the chamber 41 can control the adsorption of the reaction product generated during the etching to the chamber inner wall cover 48 or the release thereof, and this reaction product has an adverse effect on the etching. Can be suppressed.
[0038]
Next explained is a dry etching method according to the second embodiment of the invention. In the dry etching method according to the second embodiment, the dry etching apparatus shown in FIG.₂Contact holes are formed in the film. That is, first, as shown in FIG.₂After the film 62 is formed, a resist pattern 63 is formed thereon. Next, this Si substrate 61 is placed on the cathode 43 of the dry etching apparatus shown in FIG. 3, and etching is performed in two steps as described below using the resist pattern 63 as a mask to form contact holes.
[0039]
That is, first, a gas refrigerant of chlorofluorocarbon of, for example, −140 ° C. is supplied from the gas refrigerant chiller 51 to the side wall of the chamber 41, and the chamber inner wall cover 48 is rapidly cooled. The cooling rate at this time is, for example, 100 ° C./min. Next, in the same manner as in the first embodiment, SiO₂The film 62 is just etched to form a contact hole. At this time, as shown in FIG.₂The etching is interrupted with a part of the film 62 left. At this point, the first step ends. In this first step, just etching, for example, C as an etching gas._FourF₈, CO, Ar and O₂The gas flow rates are 20 sccm, 100 sccm, 150 sccm, and 5 sccm, the pressure is 50 mTorr, the RF power is 1500 W, the substrate temperature is 50 ° C., and the wall surface temperature is −50 ° C.
[0040]
Here, during the first etching process, a precursor of fluorocarbon polymer is generated, but most of the precursor is adsorbed by the chamber inner wall cover 48 at a low temperature of −50 ° C. and does not deposit on the Si substrate 61. . Therefore, just etching can be performed without causing an etching stop due to excessive deposition of the fluorocarbon polymer precursor on the Si substrate 61.
[0041]
Next, after closing the electronic control valves 52 and 53, a heater (not shown) built in the chamber inner wall cover 48 is energized to generate heat, and the inner wall of the chamber 41 is rapidly moved from -50 ° C to 200 ° C. Heat. The heating rate at this time is, for example, about 200 ° C./min, and the heating time is, for example, about 75 seconds. By this rapid heating, the fluorocarbon polymer precursor adsorbed on the chamber inner wall cover 48 during the first step just etching is quickly released into the chamber 41.
[0042]
Next, as a second step, SiO₂Overetching of the film 62 is performed. In the second step over-etching, the portion of SiO 2 left at the bottom of the contact hole 64 in the first step just etching is removed.₂Etching of the film 62 is performed until the surface of the underlying Si substrate 61 is exposed as shown in FIG. 4C. In this second step over-etching, for example, as an etching gas, C_FourF₈, CO, Ar and O₂The gas flows are 20 sccm, 100 sccm, 150 sccm, and 5 sccm, the pressure is 50 mTorr, the RF power is 1500 W, the substrate temperature is 50 ° C., and the wall surface temperature is 200 ° C.
[0043]
Here, in the overetching of the second step, since the precursor of the fluorocarbon polymer adsorbed on the surface of the chamber inner wall cover 48 is released in advance, the selection ratio with the underlying Si substrate 61 is about 100, for example. Can be as high as possible.
[0044]
According to the dry etching method of the second embodiment, a high aspect ratio can be obtained without causing an etching stop at the time of just etching in the first step or an extreme taper at the time of overetching in the second step. Thus, the fine contact hole 64 can be easily formed.
[0045]
As mentioned above, although embodiment of this invention was described concretely, this invention is not limited to the above-mentioned embodiment, The various deformation | transformation based on the technical idea of this invention is possible.
[0046]
For example, numerical values such as the temperature, the cooling rate and the heating rate, the etching gas type and flow rate, the etching pressure, the RF power, and the RF bias of the chamber inner wall covers 17 and 48 mentioned in the first and second embodiments. Is merely an example, and different numerical values may be used as necessary. Moreover, the kind of gas refrigerant used for cooling the inner wall of the chamber 41 is merely an example, and a different kind of refrigerant may be used as necessary. Moreover, as long as the material of the chamber inner-wall covers 17 and 48 mentioned in the first and second embodiments is an insulator having good thermal conductivity, a material other than AlN may be used. Furthermore, the chamber inner wall covers 17 and 48 may be bonded to the inner walls of the chambers 1 and 41 using an epoxy or AlN-based adhesive depending on circumstances.
[0047]
【The invention's effect】
As described above, according to the present invention, the temperature of the inner wall of the chamber can be rapidly controlled, so that the amount of reaction products and polymer precursors deposited on the inner wall of the chamber during etching is controlled. The gate electrode material such as a polycrystalline Si film or SiO with high selectivity without causing pattern thickening, etching stop or high taper.₂A film or the like can be etched with high accuracy and good reproducibility, and a fine contact hole can be easily formed with a fine pattern and a high aspect ratio.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a dry etching apparatus according to a first embodiment of the present invention.
FIG. 2 is a cross-sectional view of a semiconductor substrate for illustrating a dry etching method according to a first embodiment of the invention.
FIG. 3 is a schematic diagram showing a dry etching apparatus according to a second embodiment of the present invention.
FIG. 4 is a cross-sectional view of a semiconductor substrate for explaining a dry etching method according to a second embodiment of the invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Diffusion chamber, 3, 51 ... Gas refrigerant chiller, 5 ... Cylindrical quartz bell jar, 6, 11 ... RF antenna, 14, 42 ... Wafer, 18, 19, 49, 50 ... Gas refrigerant piping, 20 ... Cryogenic valve, 21 ... Bypass line cryogenic valve, 31, 61 ... Si substrate, 32, 62 ... SiO₂Membrane, 41 ... Chamber, 52, 53 ... Electronic control valve

Claims (3)

In a dry etching method in which an object to be etched is etched by just etching and subsequent overetching using a dry etching apparatus,
When performing the just etching, the inner wall of the side wall of the etching chamber of the dry etching apparatus is cooled to adsorb reaction products on the surface, and the reaction wall is heated from the inner wall of the etching chamber to generate the reaction from the surface. The over-etching was performed after discharging the material
A dry etching method characterized by the above. The inner wall of the etching chamber is cooled by supplying a gas refrigerant to a refrigerant flow path provided on the inner wall of the etching chamber by a gas refrigerant supply device via a gas refrigerant supply pipe. The dry etching method according to claim 1. The inner wall of the etching chamber is heated by a heating mechanism including a covering provided on the surface of the inner wall of the etching chamber and a heating element provided inside the covering. The dry etching method according to claim 1.

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