JP2019096650A - Plasma processing apparatus - Google Patents

Abstract

To increase resistance to plasma in a mounting table even if dry cleaning is performed.SOLUTION: A plasma etching apparatus includes an insulating layer 145 of an electrostatic chuck 132 constituting a mounting surface of a substrate mounting table 130 that mounts a substrate to be subjected to plasma processing thereon. The insulating layer 145 is formed of alumina, yttria and a silicon compound. The plasma etching apparatus 30 also includes an adsorption electrode 146 that is provided at the inside of the insulating layer 145 and adsorbs a substrate when a predetermined voltage is applied thereto. The adsorption electrode 146 is formed of a nickel-containing metal or chromium-containing metal.SELECTED DRAWING: Figure 4

Description

  Various aspects and embodiments of the present invention relate to a plasma processing apparatus.

  BACKGROUND Conventionally, plasma processing apparatuses that perform plasma processing such as etching and film formation are known. The plasma processing apparatus is provided with a mounting table on which an object to be processed such as a glass substrate is mounted. The mounting table is provided with an electrostatic chuck composed of a sprayed film of alumina, an electrode layer, a sealing agent, and the like on the upper surface on which the object to be processed is mounted. Adsorbs the object to be treated.

  By the way, in the plasma processing apparatus, dry cleaning is performed in which a cleaning gas is supplied and cleaned in order to remove a product attached on the mounting table by the plasma processing.

JP, 2008-066707, A

  However, in the plasma processing apparatus, the mounting table is consumed by the dry cleaning. For example, dry cleaning consumes the material constituting the electrostatic chuck.

  The disclosed plasma processing apparatus includes, in one embodiment, an insulating layer which constitutes a mounting surface of a mounting table on which an object to be processed of plasma processing is mounted. The insulating layer is formed of alumina, yttria and a silicon compound. In addition, the plasma processing apparatus includes an adsorption electrode which is provided in the insulating layer and adsorbs the object by applying a predetermined voltage. The adsorption electrode is formed of a nickel-containing metal or a chromium-containing metal.

  According to one aspect of the disclosed plasma processing apparatus, even in the case where dry cleaning is performed, the resistance to the plasma of the mounting table can be increased.

FIG. 1 is a cross-sectional view showing the structure of an object to which a plasma processing method according to an embodiment of the present invention is applied. FIG. 2 is a schematic plan view showing a processing system for implementing the processing method of the first embodiment. FIG. 3 is a cross-sectional view showing a plasma etching apparatus mounted on the processing system of FIG. FIG. 4 is a cross-sectional view showing the configuration of the base material and the electrostatic chuck according to the first embodiment. FIG. 5 is a view showing an example of the resistance of metals to chlorine gas. FIG. 6 is a schematic view showing a post-processing apparatus installed in the processing system of FIG. FIG. 7 is a flowchart showing the plasma processing method according to the first embodiment. FIG. 8 is a schematic view showing a reaction product generated in a chamber when an Al-containing metal film is etched using Cl ₂ gas as a processing gas. Figure 9 is produced in a chamber in the case of performing after etching the Al-containing metal layer with a Cl ₂ gas as the processing gas, O ₂ gas, or the post-treated with an O ₂ gas and CF ₄ gas reaction Figure 2 is a schematic showing the product. FIG. 10 is a schematic plan view showing a processing system for implementing the processing method of the second embodiment. It is sectional drawing which shows the plasma etching apparatus mounted in the processing system of FIG. FIG. 12 is a cross-sectional view showing the configuration of a base and an electrostatic chuck according to a second embodiment. FIG. 13 is a cross-sectional view showing an example of the vapor pressure. FIG. 14 is a cross-sectional view showing an example of a linear expansion coefficient. FIG. 15 is a flowchart showing a plasma processing method according to the second embodiment. FIG. 16 is a schematic view showing a reaction product generated in the chamber when the Mo-based material film is etched using SF ₆ gas as a processing gas. FIG. 17 is a schematic view showing a reaction product generated in the chamber when the Mo-based material film is etched using SF ₆ gas and O ₂ gas as a processing gas.

  Hereinafter, embodiments of the plasma processing apparatus disclosed in the present application will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts will be denoted by the same reference numerals. Moreover, the invention disclosed by this embodiment is not limited. The respective embodiments can be combined appropriately as long as the processing contents do not contradict each other.

<Structure of Substrate to which Plasma Processing Method According to the Embodiment of the Present Invention is Applied>
FIG. 1 is a cross-sectional view showing the structure of an object to which a plasma processing method according to an embodiment of the present invention is applied. In the present embodiment, the case where the object to be processed is the substrate S will be described as an example.

  The substrate S has a structure in which a top gate TFT is formed on a glass substrate. Specifically, as shown in FIG. 1, a light shielding layer 2 made of a Mo-based material (Mo, MoW) is formed on a glass substrate 1, and on top of that, polysilicon as a semiconductor layer is formed through an insulating film 3 A polysilicon film (p-Si film) 4 is formed, and a gate electrode 6 made of a Mo-based material (Mo, MoW) is formed thereon via a gate insulating film 5, and an interlayer insulating film 7 is formed thereon. It is formed. A contact hole is formed in interlayer insulating film 7, and source electrode 8 a and drain electrode 8 b connected to p-Si film 4 via the contact hole are formed on interlayer insulating film 7. The source electrode 8a and the drain electrode 8b are made of, for example, an Al-containing metal film of a Ti / Al / Ti structure formed by sequentially laminating a titanium film, an aluminum film, and a titanium film. A protective film (not shown) made of, for example, a SiN film is formed on the source electrode 8a and the drain electrode 8b, and a transparent electrode (not shown) connected to the source electrode 8a and the drain electrode 8b on the protective film. ) Is formed.

First Embodiment
First, the first embodiment will be described. In the first embodiment, an etching process of an Al-containing metal film when forming the source electrode 8 a and the drain electrode 8 b of the substrate S shown in FIG. 1 will be described as an example. When etching the Al-containing metal film for forming the source electrode 8a and the drain electrode 8b, a resist film (not shown) having a predetermined pattern is formed thereon, and plasma etching is performed using the resist film as a mask. It will be.

[Device Configuration of Processing System, Plasma Etching Device Etc. Used in First Embodiment]
First, apparatus configurations such as a processing system and a plasma etching apparatus used in the first embodiment will be described.

  FIG. 2 is a schematic plan view showing a processing system for implementing the processing method of the first embodiment. FIG. 3 is a cross-sectional view showing a plasma etching apparatus mounted on the processing system of FIG. FIG. 6 is a schematic view showing a post-processing apparatus installed in the processing system of FIG.

  As shown in FIG. 2, the processing system 100 is a multi-chamber type processing system, and includes a vacuum transfer chamber 10, a load lock chamber 20, two plasma etching devices 30, and a post-processing device 40. There is. The plasma etching apparatus 30 and the post-processing apparatus 40 are processed in a predetermined reduced pressure atmosphere. The vacuum transfer chamber 10 has a rectangular planar shape. The load lock chamber 20, the two plasma etching devices 30 and the post-processing device 40 are connected to the respective walls of the vacuum transfer chamber 10 via gate valves G. A carrier 50 that accommodates a rectangular substrate S is disposed outside the load lock chamber 20.

  A transport mechanism 60 is provided between the two carriers 50. The transport mechanism 60 is provided with picks 61 (only one is shown) provided in two upper and lower stages, and these are integrally advanced and retracted and rotated. It has a base 62 which can be supported.

  The vacuum transfer chamber 10 can be maintained in a predetermined reduced pressure atmosphere, and as shown in FIG. 2, a vacuum transfer mechanism 70 is provided therein. Then, the substrate S is transported between the load lock chamber 20, the two plasma etching devices 30, and the post-processing device 40 by the vacuum transport mechanism 70. In the vacuum transfer mechanism 70, two substrate transfer arms 72 (only one is shown) are provided on a pivotable and vertically movable base 71 so as to be movable back and forth.

  The load lock chamber 20 is for transferring the substrate S between the carrier 50 in the air atmosphere and the vacuum transfer chamber 10 in the reduced pressure atmosphere, and it is possible to switch between the vacuum atmosphere and the air atmosphere in a short time. It can be done. Substrate holders (not shown) are provided in upper and lower two stages in the load lock chamber 20, and a substrate S is positioned in each substrate holder by a positioner (not shown).

The plasma etching apparatus 30 is for etching the Al-containing metal film of the substrate S, and as shown in FIG. 3, for example, a rectangular cylindrical airtight main body container whose inner wall surface is made of anodized aluminum. It has 101. The main container 101 is grounded. The main container 101 is divided up and down by the dielectric wall 102, the upper side is an antenna container 103 defining an antenna chamber, and the lower side is a chamber (processing container) 104 defining a processing chamber. There is. The dielectric wall 102 constitutes a ceiling wall of the chamber 104, and is made of ceramics such as Al ₂ O ₃ , quartz or the like.

  Between the side wall 103 a of the antenna case 103 and the side wall 104 a of the chamber 104 in the main body case 101, a support shelf 105 projecting inward is provided. The dielectric wall 102 is placed on the support shelf 105.

  In the lower part of the dielectric wall 102, a shower case 111 for supplying a processing gas is fitted. The shower housing 111 is provided in a cross shape, and has a beam structure for supporting the dielectric wall 102 from below. The shower case 111 is suspended from the ceiling of the main body container 101 by a plurality of suspenders (not shown).

  The shower housing 111 is made of a conductive material, for example, aluminum whose inner surface or outer surface is anodized. A gas flow passage 112 extending horizontally is formed in the shower casing 111, and a plurality of gas discharge holes 112a extending downward are in communication with the gas flow passage 112.

On the other hand, a gas supply pipe 121 is provided at the center of the upper surface of the dielectric wall 102 so as to communicate with the gas flow path 112. The gas supply pipe 121 penetrates from the ceiling of the main body container 101 to the outside thereof and is branched into branch pipes 121a and 121b. A chlorine-containing gas supply source 122 for supplying a chlorine-containing gas such as a Cl ₂ gas is connected to the branch pipe 121a. Further, the branch pipe 121b is connected to an inert gas supply source 123 for supplying an inert gas such as Ar gas or N ₂ gas, which is used as a purge gas or a dilution gas. The chlorine-containing gas is used as an etching gas and a dry cleaning gas. The branch pipes 121a and 121b are provided with flow controllers such as mass flow controllers and a valve system.

  The gas supply pipe 121, the branch pipes 121a and 121b, the chlorine-containing gas supply source 122, the inert gas supply source 123, the flow rate controller and the valve system constitute a processing gas supply mechanism 120.

In the plasma etching apparatus 30, the chlorine-containing gas supplied from the processing gas supply mechanism 120 is supplied into the shower housing 111 and discharged from the gas discharge holes 112a on the lower surface thereof into the chamber 104, and the Al content of the substrate S is contained. Etching of the metal film or dry cleaning of the chamber 104 is performed. The dry cleaning is a process of removing a reaction product deposited in the chamber 104 without opening the chamber 104 by supplying a cleaning gas. The chlorine-containing gas is preferably chlorine (Cl ₂ ) gas, but boron trichloride (BCl ₃ ) gas, carbon tetrachloride (CCl ₄ ) gas or the like can also be used.

  In the antenna container 103, a radio frequency (RF) antenna 113 is disposed. The high frequency antenna 113 is configured by arranging an antenna wire 113a made of a metal with good conductivity such as copper or aluminum in an arbitrary shape conventionally used such as annular or spiral. The high frequency antenna 113 may be a multiple antenna having a plurality of antenna units. The high frequency antenna 113 is separated from the dielectric wall 102 by a spacer 117 made of an insulating member.

  A feed member 116 extending above the antenna container 103 is connected to the terminal 118 of the antenna wire 113a. A feed line 119 is connected to the upper end of the feed member 116, and a matching unit 114 and a high frequency power supply 115 are connected to the feed line 119. Then, a high frequency power having a frequency of, for example, 13.56 MHz is supplied from the high frequency power source 115 to the high frequency antenna 113, whereby an induction electric field is formed in the chamber 104, and the treatment electric field is supplied from the shower casing 111 by this induction electric field. The gas is plasmatized to produce an inductively coupled plasma.

  A substrate mounting table 130 on which the substrate S is mounted is provided on the bottom wall in the chamber 104 via a spacer 134 made of a frame-like insulator. The substrate mounting table 130 is a substrate 131 provided on the above-described spacer 134, an electrostatic chuck 132 provided on the substrate 131, and a side wall covering the sidewalls of the substrate 131 and the electrostatic chuck 132. And an insulating member 133. The base material 131 and the electrostatic chuck 132 have a rectangular shape corresponding to the shape of the substrate S, and the entire substrate mounting table 130 is formed in a square plate shape or a columnar shape. The spacer 134 and the side wall insulating member 133 are made of insulating ceramic such as alumina.

  The electrostatic chuck 132 has an insulating layer 145 made of a dielectric such as a ceramic sprayed film formed on the surface of the base material 131, and a suction electrode 146 provided inside the insulating layer 145.

  Here, the configurations of the base material 131 and the electrostatic chuck 132 will be described with reference to FIG. FIG. 4 is a cross-sectional view showing the configuration of the base material and the electrostatic chuck according to the first embodiment.

  The electrostatic chuck 132 is disposed on the substrate 131. The substrate 131 is made of, for example, stainless steel. By using stainless steel, the substrate 131 can be used as a high temperature electrode, and can be used in a plasma environment of a chlorine-containing gas or in a plasma environment of a fluorine-containing gas described later.

  The electrostatic chuck 132 has an insulating layer 145 and a suction electrode 146 provided inside the insulating layer 145. The insulating layer 145 includes two upper insulating layers 145 a and lower insulating layers 145 b which overlap in the vertical direction. In the present embodiment, the insulating layer 145 includes an upper insulating layer 145 a on the substrate S side with respect to the suction electrode 146 and a lower insulating layer 145 b on the opposite side of the substrate S with respect to the suction electrode 146.

The upper insulating layer 145a and the lower insulating layer 145b are composed of a mixed spray film. The mixed sprayed film is formed by spraying a mixture of alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ), and a silicon compound. Y ₂ O ₃ is highly resistant to plasma in terms of the material. Also, Al ₂ O ₃ has high chemical resistance to chlorine-containing gas. Further, silicon compounds, because of the effect of densification to fill the grain boundaries of the Y ₂ O ₃ and Al ₂ O ₃ becomes glassy mixture sprayed coating, the plasma of the chlorine-containing gas ₂ gas or the like Cl Has high resistance to. As the mixed spray coating, an Al ₂ O ₃ .Y ₂ O ₃ .SiO ₂ film using silicon oxide (SiO ₂ ) as a silicon compound is preferable. In addition, an Al ₂ O ₃ .Y ₂ O ₃ .SiO ₂ .Si ₃ N ₄ film using silicon nitride (Si ₃ N ₄ ) as a silicon compound can also be suitably used.

  Conventionally, the insulating layer 145 is subjected to sealing treatment with a sealing member in order to enhance the insulation. However, when dry sealing is performed, the sealing member may be separated from the insulating layer 145 to cause particles. Therefore, in the present embodiment, only the lower insulating layer 145b of the upper insulating layer 145a and the lower insulating layer 145b is subjected to the sealing treatment by the sealing member. That is, the upper insulating layer 145a is not sealed. As a result, the upper insulating layer 145a is not subjected to sealing treatment, whereby generation of particles when dry cleaning is performed can be suppressed.

  In order not to seal the upper insulating layer 145a, the adsorption electrode 146 needs to use a metal that is less corrosive to chlorine gas. Therefore, the adsorption electrode 146 is made of a nickel-containing metal. For example, the adsorption electrode 146 is formed of any of Ni-5Al, SUS316L, or Hastelloy. These nickel-containing metals have high resistance to chlorine-containing gas plasma. Pure nickel is not preferable as the adsorption electrode 146 because it is ferromagnetic. As the adsorption electrode 146, it is preferable to use a nickel-containing metal which is less magnetic.

  FIG. 5 is a view showing an example of the resistance of metals to chlorine gas. FIG. 5 shows the amount of scraping of a Cl gas system as a chlorine gas for Cr, Ni-5Al, SUS316L and hastelloy, and tungsten (W) and molybdenum (Mo) conventionally used for the adsorption electrode 146. It is done. In addition, the amount of removal shown in FIG. 5 is taken as the value normalized on the basis of the amount of removal of Ni-5Al, and the decimal point or less is rounded off. As shown in FIG. 5, Ni-5Al, SUS316L and hastelloy have a small amount of scraping and high resistance to chlorine-based gas.

  Further, since the upper insulating layer 145a is not subjected to sealing treatment, it is preferable to perform thermal spraying densely. In the case where the upper insulating layer 145a has a possibility of raising the temperature, for example, by providing the electrostatic chuck 132 with a heating function or transferring heat from the base material 131, the heat resistance is lowered if it is too dense. , Need some degree of vacancies. Therefore, the upper insulating layer 145a is formed by quasi-dense mixed thermal spraying. The upper insulating layer 145a preferably has a porosity in the range of 1.5% to 4%. It is more preferable that the porosity be in the range of 2.1% to 3.1%. Accordingly, the upper insulating layer 145a can suppress the inflow of gas into the inside and can suppress the gas reaching the adsorption electrode 146. The lower insulating layer 145b may also be formed by semi-dense mixed spraying as in the case of the upper insulating layer 145a.

  The adsorption electrode 146 can take various forms such as a plate, a film, a grid, and a net. As shown in FIG. 3, a DC power supply 148 is connected to the adsorption electrode 146 via a feed line 147, and a DC voltage is applied to the adsorption electrode 146. Power supply to the adsorption electrode 146 is turned on and off by a switch (not shown). By applying a DC voltage to the adsorption electrode 146, an electrostatic adsorption force is generated by the coulomb force, and the substrate S is adsorbed.

  A high frequency power supply 153 for bias application is connected to the base material 131 via a feeder line 151. In addition, a matching unit 152 is provided between the base material 131 of the feed line 151 and the high frequency power supply 153. The high frequency power source 153 is for drawing ions into the substrate S on the base material 131, and a frequency in the range of 50 kHz to 10 MHz is used, for example, 3.2 MHz.

  In addition, in the base material 131 of the substrate mounting stand 130, in order to control the temperature of the board | substrate S, temperature control mechanisms and temperature sensors (all are not shown), such as a heater and a refrigerant flow path, are provided. Further, a heat transfer gas supply mechanism (for example, He gas) for supplying a heat transfer gas for heat transfer between the substrate S and the substrate mounting table 130 in a state where the substrate S is mounted on the substrate mounting table 130 ( Not shown). Furthermore, on the substrate mounting table 130, a plurality of lifting pins (not shown) for delivering the substrate S are provided so as to be able to protrude and retract with respect to the upper surface of the electrostatic chuck 132. This is performed on the raising and lowering pins in a state of projecting upward from the upper surface of the electrostatic chuck 132.

  A loading / unloading port 155 for loading / unloading the substrate S into / from the chamber 104 is provided on the side wall 104 a of the chamber 104, and the loading / unloading port 155 can be opened and closed by the gate valve G. By opening the gate valve G, the vacuum transfer mechanism 70 provided in the vacuum transfer chamber 10 enables loading and unloading of the substrate S through the loading / unloading port 155.

  At the edge or corner of the bottom wall of the chamber 104, a plurality of exhaust ports 159 (only two shown) are formed. Each exhaust port 159 is provided with an exhaust unit 160. The exhaust unit 160 includes an exhaust pipe 161 connected to the exhaust port 159, an automatic pressure control valve (APC) 162 that controls the pressure in the chamber 104 by adjusting the opening degree of the exhaust pipe 161, and the inside of the chamber 104. And a vacuum pump 163 for exhausting air through an exhaust pipe 161. Then, the inside of the chamber 104 is evacuated by the vacuum pump 163, and the inside of the chamber 104 is set and maintained at a predetermined vacuum atmosphere by adjusting the opening degree of the automatic pressure control valve (APC) 162 during the plasma etching process.

  The post-processing apparatus 40 is for performing post-processing for corrosion suppression after etching the Al-containing metal film of the substrate S. The post-processing apparatus 40 has a processing gas supply mechanism 120 ′ for supplying a gas different from that of the plasma etching apparatus 30 instead of the processing gas supply mechanism 120, as shown in FIG. 6. Although the configuration other than that is omitted in FIG. 6, the configuration is the same as that of the plasma etching apparatus 30. In the following description, the same members as in the plasma etching apparatus 30 will be described with the same reference numerals.

The processing gas supply mechanism 120 'of the post-processing apparatus 40 includes a gas supply pipe 121', branch pipes 121a ', 121b', and 121c 'branched from the gas supply pipe 121' at the upper outside of the main vessel 101, and a branch pipe 121a. 'connected to, and _{O 2} gas supply source 124 for supplying an _{O 2} gas, the branch pipes 121b' is connected to a fluorine-containing gas supply source 125 for supplying a fluorine-containing gas, is connected to the branch pipes 121c ' And an inert gas supply source 126 for supplying an inert gas such as Ar gas or N ₂ gas as a purge gas or a dilution gas. The gas supply pipe 121 'is connected to the gas flow path 112 of the shower enclosure 111 as in the case of the gas supply pipe 121 of the plasma etching apparatus 30 (see FIG. 3). The branch pipes 121a ', 121b' and 121c 'are provided with flow controllers such as mass flow controllers and a valve system.

In the post-processing apparatus 40, the O ₂ gas or the O ₂ gas and the fluorine-containing gas supplied from the processing gas supply mechanism 120 ′ are discharged into the chamber 104 through the shower housing 111, and the substrate S is etched. A corrosion suppression process is performed on the Al-containing metal film. Although carbon tetrafluoride (CF ₄ ) can be suitably used as the fluorine-containing gas, sulfur hexafluoride (SF ₆ ) or the like can also be used.

In the post-processing apparatus 40, since the insulating layer 145 of the electrostatic chuck 132 is not required to be resistant to plasma of a chlorine-containing gas, the insulating layer 145 is made of Al ₂ O ₃ or Y ₂ O ₃ as in the conventional case. It can comprise with the thermal-sprayed film which becomes. Further, since the post-processing device 40 only performs the corrosion suppression process, the electrostatic chuck 132 may not be provided.

  The processing system 100 further includes a control unit 80. The control unit 80 is configured by a computer including a CPU and a storage unit, and each component of the processing system 100 (a vacuum transfer chamber 10, a load lock chamber 20, a plasma etching apparatus 30, a post-processing apparatus 40, a transfer mechanism 60). Each component of the vacuum transfer mechanism 70 is controlled to perform a predetermined process based on the process recipe (program) stored in the storage unit. The processing recipe is stored in a storage medium such as a hard disk, a compact disk, or a semiconductor memory.

[Plasma processing method according to the first embodiment]
Next, a plasma processing method according to the first embodiment of the above processing system 100 will be described with reference to the flowchart of FIG. FIG. 7 is a flowchart showing the plasma processing method according to the first embodiment.

  Here, the plasma etching process of the Ti / Al / Ti film which is an Al-containing metal film for forming the source electrode 8 a and the drain electrode 8 b formed on the substrate S is performed by the processing system 100.

  First, in the plasma etching process in the plasma etching apparatus 30, a process gas is selected so that the generated reaction product can be dry-cleaned (step 1).

Specifically, in the present embodiment, a chlorine-containing gas, for example, a Cl ₂ gas is selected as the processing gas. FIG. 8 is a schematic view showing a reaction product generated in a chamber when an Al-containing metal film is etched using Cl ₂ gas as a processing gas. When plasma etching a Ti / Al / Ti film using a chlorine-containing gas, as shown in FIG. 8, AlClx is mainly generated as a reaction product, and a part of these deposits on the chamber wall and deposits ( Depot). The AlClx has a high vapor pressure and can be removed by dry cleaning.

Figure 9 is produced in a chamber in the case of performing after etching the Al-containing metal layer with a Cl ₂ gas as the processing gas, O ₂ gas, or the post-treated with an O ₂ gas and CF ₄ gas reaction Figure 2 is a schematic showing the product. On the other hand, as shown in FIG. 9, when performing post-treatment for corrosion suppression in the same chamber after etching a Ti / Al / Ti film with Cl ₂ gas as in the prior art, O ₂ gas is used as a post-treatment gas When supplied and plasma treatment is performed, the deposited AlClx reacts with the O ₂ gas to generate AlO x having a low vapor pressure in the chamber. Further, when a fluorine-containing gas, for example, CF ₄ gas is supplied in addition to the O ₂ gas to further enhance the corrosion suppression effect, AlF x having a low vapor pressure is also generated in the chamber in addition to AlO x. Since AlOx and AlFx have a low vapor pressure, they do not volatilize and easily adhere to the chamber wall to form a deposit. And if this peels off, it causes particles and adversely affects the product. Moreover, since these are highly stable, they are difficult to remove by dry cleaning.

Therefore, in the present embodiment, AlClx capable of dry cleaning is generated as a reaction product in the chamber, and a substrate in the plasma etching apparatus 30 is generated so that AlOx and AlFx difficult to be removed by dry cleaning. The processing gas of S is only a chlorine-containing gas (Cl ₂ gas) which is an etching gas.

After selecting the processing gas for plasma etching in this way, the Ti / Al / Ti film, which is an Al-containing metal film formed on the substrate S, is selected by the plasma etching apparatus 30 in advance using the processing gas. A plasma etching process is performed using a certain chlorine-containing gas, for example, Cl ₂ gas (step 2).

  Hereinafter, the plasma etching process of step 2 will be specifically described.

  The substrate S is taken out of the carrier 50 by the transport mechanism 60 and transported to the load lock chamber 20, and the vacuum transport mechanism 70 in the vacuum transport chamber 10 receives the substrate S from the load lock chamber 20 and transports the substrate S to the plasma etching apparatus 30.

  In the plasma etching apparatus 30, first, the inside of the chamber 104 is adjusted to a pressure compatible with the vacuum transfer chamber 10 by the vacuum pump 163, the gate valve G is opened, and the substrate S is chamber 104 by the vacuum transfer mechanism 70 from the loading / unloading port 155. Then, the substrate S is placed on the substrate mounting table 130. After evacuating the vacuum transfer mechanism 70 from the chamber 104, the gate valve G is closed.

In this state, the pressure in the chamber 104 is adjusted to a predetermined degree of vacuum by an automatic pressure control valve (APC) 162 and chlorine as an etching gas as a processing gas from the processing gas supply mechanism 120 via the shower housing 111 A contained gas, for example, Cl ₂ gas is supplied into the chamber 104. In addition to the chlorine-containing gas, an inert gas such as Ar gas may be supplied as a dilution gas.

  At this time, the substrate S is attracted by the electrostatic chuck 132 and temperature-controlled by a temperature control mechanism (not shown).

  Next, a high frequency of 13.56 MHz, for example, is applied from the high frequency power source 115 to the high frequency antenna 113, thereby forming a uniform induction electric field in the chamber 104 via the dielectric wall 102. The induction electric field thus formed generates a plasma of a chlorine-containing gas. The Ti / Al / Ti film which is the Al-containing metal film of the substrate S is etched by the high density inductively coupled plasma generated in this manner.

  At this time, in the plasma etching apparatus 30, AlClx is generated as a reaction product as described above, and a part thereof adheres to a wall or the like in the chamber 104. On the other hand, AlOx and AlFx are hardly generated.

Next, with respect to the Ti / Al / Ti film which is the Al-containing metal film of the substrate S after plasma etching, an O ₂ gas or an O ₂ gas and a fluorine-containing gas, for example, a CF ₄ gas Post-processing for corrosion suppression is performed (step 3).

  The post-processing of step 3 will be specifically described below.

  The substrate S after the etching process is taken out of the plasma etching apparatus 30 by the vacuum transfer mechanism 70 and transferred to the post-processing apparatus 40.

In the post-processing apparatus 40, as in the plasma etching apparatus 30, the substrate S is carried into the chamber 104, mounted on the substrate mounting table 130, and the pressure in the chamber 104 is adjusted to a predetermined degree of vacuum and processing As a post-treatment gas, O ₂ gas or O ₂ gas and a fluorine-containing gas, for example, CF ₄ gas are supplied into the chamber 104 from the gas supply mechanism 120 ′ via the shower housing 111. In addition to these, an inert gas such as Ar may be supplied as a dilution gas.

Then, similarly to the plasma etching apparatus 30, plasma of O ₂ gas as a post-treatment gas or O ₂ gas and fluorine-containing gas is generated by the induction electric field, and etched by the inductively coupled plasma generated in this manner. The corrosion suppression processing of the Ti / Al / Ti film which is the Al-containing metal film is performed.

  At this time, in the post-processing apparatus 40, the amount of generated reaction products is small because the etching process is not performed.

  The substrate S after post-processing in the post-processing apparatus 40 is taken out of the chamber 104 of the post-processing apparatus 40 by the vacuum transfer mechanism 70, transferred to the load lock chamber 20, and returned to the carrier 50 by the transfer mechanism 60.

  After the plasma etching process (step 2) and the post-processing (step 3) described above are performed one or two or more predetermined times, the dry cleaning process in the chamber 104 of the plasma etching apparatus 30 is performed (step 4) ).

In the dry cleaning, a chlorine-containing gas, for example, a Cl ₂ gas is supplied as a dry cleaning gas into the chamber 104 in the same manner as an etching gas in plasma etching without mounting the substrate S on the substrate mounting table 130. The same inductive coupling plasma as in plasma etching is used.

By this dry cleaning, AlClx attached to the chamber 104 of the plasma etching apparatus 30 can be removed. That is, in the plasma etching apparatus 30, conventional as, O ₂ gas or is not performed corrosion inhibition treatment with O ₂ gas and fluorine-containing gas, are difficult AlOx and AlFx removed by dry cleaning as a reaction product, produced Dry cleaning becomes possible without doing.

  Further, during dry cleaning, the substrate S is not mounted on the substrate mounting table 130, and the substrate S does not exist on the electrostatic chuck 132, so the plasma of chlorine-containing gas, which is a dry cleaning gas, is directly electrostatic chuck Acts on 132.

Conventionally, since the plasma etching apparatus does not perform dry cleaning, plasma processing is not performed without placing the substrate S on the electrostatic chuck, and the insulating layer of the electrostatic chuck is made of Y ₂ O ₃ or Al ₂ O The sprayed film of ₃ was sufficient. However, it has been found that if the plasma of a chlorine-containing gas directly acts during dry cleaning, the insulating layer is damaged by the sprayed film of Y ₂ O ₃ or Al ₂ O ₃ and the life may be shortened. In order to solve this problem, it is conceivable that dry cleaning is performed in a state where the raw glass which is a dummy substrate is mounted on the substrate mounting table 130 at the time of dry cleaning. In this case, the raw glass is used. A process of carrying in / out the plasma etching apparatus 30 occurs, and the productivity is reduced.

Therefore, in the present embodiment, a mixed sprayed film formed by spraying a mixture of Al ₂ O ₃ , Y ₂ O ₃ and a silicon compound is used as the insulating layer 145 of the electrostatic chuck 132. Y ₂ O ₃ is high in plasma resistance as a material, Al ₂ O ₃ is high in chemical resistance to chlorine-containing gas, and silicon compounds are vitrified to become Y ₂ O ₃ and Al ₂ O ₃ . Since the mixed thermal spray coating has high resistance to plasma of chlorine-containing gas such as Cl ₂ gas because it has the function of filling grain boundaries and densifying it, it is desirable to mount the raw glass during dry cleaning, without putting it on. It can maintain the life. In addition, the insulating layer 145 includes an upper insulating layer 145 a on the substrate S side with respect to the suction electrode 146 and a lower insulating layer 145 b on the opposite side of the substrate S with respect to the suction electrode 146. The lower insulating layer 145 b is subjected to sealing treatment with a sealing member. The upper insulating layer 145a is not sealed. By thus not sealing the upper insulating layer 145a, generation of particles from the sealing member can be suppressed at the time of dry cleaning.

As described above, a mixed sprayed film of Al ₂ O ₃ , Y ₂ O ₃ , and SiO ₂ is preferable as the mixed sprayed film. _The mixing sprayed film _{of Al 2 O 3 · Y 2 O} 3 · SiO 2 · Si 3 N 4 can also be suitably used. Further, the adsorption electrode 146 of the electrostatic chuck 132 exhibits high resistance to the plasma of the chlorine-containing gas by using Ni-5Al, SUS316L, or hastelloy.

  As described above, after the plasma etching process (step 2) and the post-processing (step 3) are performed a predetermined number of times, the cycle of performing the dry cleaning (step 4) is repeated, and deposition deposited in the chamber 104 of the plasma etching apparatus 30 Peeling starts to occur on objects (depots). Therefore, after repeating such a cycle a predetermined number of times, the chamber 104 is opened and chamber wet cleaning (step 5) is performed. The chamber wet cleaning is performed by wiping the deposit with alcohol, cleaning with a special chemical solution, or the like.

  As described above, the plasma etching apparatus 30 has the insulating layer 145 of the electrostatic chuck 132 which constitutes the mounting surface of the substrate mounting table 130 on which the substrate S to be subjected to plasma processing is mounted. The insulating layer 145 is formed of alumina, yttria and a silicon compound. The plasma etching apparatus 30 further includes an adsorption electrode 146 which is provided in the insulating layer 145 and adsorbs the substrate S when a predetermined voltage is applied. The adsorption electrode 146 is formed of a nickel-containing metal. Thus, the plasma etching apparatus 30 can increase the resistance of the substrate mounting table 130 to plasma even when dry cleaning is performed. As a result, in the plasma etching apparatus 30, deposits (deposits) in the chamber can be removed by dry cleaning, and the cycle of the chamber cleaning performed by opening the chamber, that is, the maintenance cycle can be significantly extended.

  In addition, the plasma etching apparatus 30 performs a plasma etching process using plasma of a chlorine-containing gas. The adsorption electrode 146 is formed of a nickel-containing metal. For example, the adsorption electrode 146 is formed of any of Ni-5Al, SUS316L, or Hastelloy. Thereby, since the adsorption electrode 146 has resistance to the plasma of the chlorine-containing gas at the time of dry cleaning, the life of the electrostatic chuck can be secured even if dry cleaning is performed.

  Further, in the plasma etching apparatus 30, the insulating layer 145 is formed by the upper insulating layer 145a on the substrate S side with respect to the suction electrode 146, and the lower insulating layer 145b on the opposite side of the substrate S with respect to the suction electrode 146. It is done. In the plasma etching apparatus 30, only the lower insulating layer 145b is sealed by the sealing member. Thereby, the plasma etching apparatus 30 can suppress the generation of particles from the sealing member at the time of dry cleaning.

Further, the processing system 100 is configured such that the processing gas for processing the substrate S is a chlorine-containing gas which is an etching gas so that the reaction product generated in the etching processing in the plasma etching apparatus 30 can be dry-cleaned. For example, only Cl ₂ gas is used. Then, the processing system 100 performs plasma processing with O ₂ gas or O ₂ gas and fluorine-containing gas for corrosion suppression, which has conventionally been performed in the same chamber after etching, with the post-processing device 40 separately provided. Therefore, in the plasma etching apparatus 30, AlOx and AlFx having a low vapor pressure are not generated during the plasma etching process, and only deposits having a high vapor pressure are AlClx generated in the chamber. Therefore, in the plasma etching apparatus 30, deposits (deposits) in the chamber are reduced as compared with the prior art, and deposits (deposits) in the chamber can be removed by dry cleaning. As a result, the processing system 100 can significantly prolong the cycle of the chamber cleaning performed by opening the chamber of the plasma etching apparatus 30, that is, the maintenance cycle.

Second Embodiment
Next, a second embodiment will be described. In the present embodiment, an etching process of the Mo-based material film in forming the gate electrode 6 or the light shielding layer 2 of the substrate S shown in FIG. 1 will be described as an example. When etching the Mo-based material film for forming the gate electrode 6 or the light shielding layer 2, a resist film (not shown) having a predetermined pattern is formed thereon, and plasma etching is performed using the resist film as a mask. It will be.

[Processing System Used in Second Embodiment and Apparatus Configuration of Plasma Etching Apparatus]
First, an apparatus configuration of a processing system and a plasma etching apparatus used in the second embodiment will be described. FIG. 10 is a schematic plan view showing a processing system for implementing the processing method of the present embodiment. FIG. 11 is a cross-sectional view showing a plasma etching apparatus mounted on the processing system of FIG.

  As shown in FIG. 10, the processing system 200 is basically configured as a multi-chamber type processing system similar to the processing system 100 of FIG. The processing system 200 of this embodiment has the same configuration as the processing system 100 of FIG. 2 except that three plasma etching apparatuses 90 are provided instead of the two plasma etching apparatuses 30 and the post-processing apparatus 40. Have. The other configuration is the same as that of FIG.

  The plasma etching apparatus 90 is for etching the Mo-based material film of the substrate S, and as shown in FIG. 11, a processing gas supply mechanism 220 is provided instead of the processing gas supply mechanism 120, and the electrostatic chuck 132 is provided. The plasma etching apparatus 30 has the same configuration as that of the plasma etching apparatus 30 of FIG. Therefore, the same components as those in FIG.

The processing gas supply mechanism 220 includes SF ₆ gas, which is a fluorine-containing gas, connected to the gas supply pipe 221, branch pipes 221a and 221b branching from the gas supply pipe 221 at the upper outside of the main vessel 101, and the branch pipe 221a. the has a SF ₆ gas supply source 222 supplies, connected to the branch pipe 221b, Ar gas as a purge gas or diluted gas, and an inert gas supply source 223 for supplying an inert gas such as N2 gas. The gas supply pipe 221 is connected to the gas flow path 112 of the shower housing 111 as in the case of the gas supply pipe 121 of the plasma etching apparatus 30 of FIG. 3. The fluorine-containing gas is used as an etching gas and a dry cleaning gas. In addition to CF ₆ gas, CF ₄ or NF ₃ can also be used as the fluorine-containing gas.

  The electrostatic chuck 232 has an insulating layer 245 formed of a ceramic sprayed film formed on the surface of the base material 131, and a suction electrode 246 provided inside the insulating layer 245.

  Here, the configurations of the base material 131 and the electrostatic chuck 232 will be described with reference to FIG. FIG. 12 is a cross-sectional view showing the configuration of a base and an electrostatic chuck according to a second embodiment.

  The electrostatic chuck 232 is disposed on the substrate 131. The substrate 131 is made of, for example, stainless steel. The base material 131 can be used as a high temperature electrode by using stainless steel, and can be used either in a plasma environment of a chlorine-containing gas or in a plasma environment of a fluorine-containing gas.

  The electrostatic chuck 232 has an insulating layer 245 and a suction electrode 246 provided inside the insulating layer 245. The insulating layer 245 has two upper insulating layers 245 a and lower insulating layers 245 b which overlap in the vertical direction. In the present embodiment, the insulating layer 245 has an upper insulating layer 245 a that is on the side of the substrate S with respect to the suction electrode 246 and a lower insulating layer 245 b that is on the opposite side of the substrate S with respect to the suction electrode 246.

The upper insulating layer 245a and the lower insulating layer 245b are composed of a mixed spray film. The mixed sprayed film is formed by spraying a mixture of alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ), and a silicon compound. Y ₂ O ₃ is highly resistant to plasma in terms of the material. Furthermore, the silicon compound has the effect of vitrifying and filling the grain boundaries of Y ₂ O ₃ and Al ₂ O ₃ and densifying it, so that the mixed spray coating is suitable for plasma of fluorine-containing gas such as SF ₆ gas. Has high resistance to. As the mixed spray coating, an Al ₂ O ₃ .Y ₂ O ₃ .SiO ₂ film using silicon oxide (SiO ₂ ) as a silicon compound is preferable. In addition, an Al ₂ O ₃ .Y ₂ O ₃ .SiO ₂ .Si ₃ N ₄ film using silicon nitride (Si ₃ N ₄ ) as a silicon compound can also be suitably used.

  Also in this embodiment, only the lower insulating layer 245b of the upper insulating layer 245a and the lower insulating layer 245b is subjected to the sealing treatment by the sealing member. That is, the upper insulating layer 245a is not sealed. Thus, the sealing process is not performed on the upper insulating layer 245a, which can suppress the generation of particles when the dry cleaning is performed.

  In order not to seal the upper insulating layer 245a, the adsorption electrode 246 needs to use a metal that is less corrosive to the fluorine-containing gas. Therefore, the adsorption electrode 246 is made of a chromium-containing metal. For example, the adsorption electrode 246 is formed of chromium (Cr). The chromium (Cr) has a lower vapor pressure of chloride and fluoride than tungsten (W) and molybdenum (Mo) conventionally used for the adsorption electrode.

  FIG. 13 is a cross-sectional view showing an example of the vapor pressure. FIG. 13 shows the vapor pressures of chromium (Cr), tungsten (W), molybdenum (Mo) chloride and fluoride at different temperatures. Chromium (Cr) has a lower vapor pressure of chloride and fluoride than tungsten (W) and molybdenum (Mo). Therefore, chromium (Cr) is more resistant to fluorine-containing gas than tungsten (W) and molybdenum (Mo).

Further, chromium (Cr) has a linear expansion coefficient closer to that of alumina (Al ₂ O ₃ ) and yttria (Y ₂ O ₃ ) than tungsten (W) and molybdenum (Mo).

FIG. 14 is a cross-sectional view showing an example of a linear expansion coefficient. FIG. 14 shows the linear expansion coefficients (a) of chromium (Cr), tungsten (W), molybdenum (Mo), alumina (Al ₂ O ₃ ) and yttria (Y ₂ O ₃ ). Further, in chromium (Cr), tungsten (W), and molybdenum (Mo), the difference (Δa) in linear expansion coefficient between alumina (Al ₂ O ₃ ) and yttria (Y ₂ O ₃ ) is shown. As shown in FIG. 14, chromium (Cr) has a linear expansion coefficient closer to that of alumina (Al ₂ O ₃ ) and yttria (Y ₂ O ₃ ) than tungsten (W) and molybdenum (Mo). As a result, the electrostatic chuck 232 is made of chromium (Cr) and the thermal spray cracking of the insulating layer 245 is less likely to occur even when the temperature becomes high.

  The upper insulating layer 245a is preferably subjected to dense thermal spraying by quasi-dense mixed thermal spraying in the same manner as the upper insulating layer 145a of the first embodiment because sealing treatment is not performed.

  The adsorption electrode 246 can take various forms such as a plate, a film, a lattice, a mesh and the like. A DC power supply 148 is connected to the adsorption electrode 246 via a feeder line 147, and a DC voltage is applied to the adsorption electrode 246. Power supply to the adsorption electrode 246 is turned on and off by a switch (not shown). By applying a DC voltage to the adsorption electrode 246, an electrostatic adsorption force is generated by the coulomb force, and the substrate S is adsorbed.

The insulating layer 245 of the electrostatic chuck 232 is composed of a mixed sprayed film formed by spraying a mixture of alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ) and a silicon compound, or Y ₂ O ₃ ing. Further, the attraction electrode 246 of the electrostatic chuck 232 is made of chromium (Cr). A mixture of alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ), and a silicon compound constituting the insulating layer 245, Y ₂ O ₃ , and Al constituting the adsorption electrode 246 are SF, which is a fluorine-based gas. _It has high resistance to ₆ plasmas.

[Plasma processing method according to the second embodiment]
Next, a plasma processing method according to the second embodiment of the above processing system 200 will be described with reference to the flowchart of FIG. FIG. 15 is a flowchart showing a plasma processing method according to the second embodiment.

  Here, the plasma etching process of the Mo-based material film formed on the substrate S, for example, the Mo film or the MoW film is performed by the processing system 200.

  First, in the plasma etching process in the plasma etching apparatus 90, a process gas is selected so that the reaction product generated can be dry-cleaned (step 11).

Specifically, in the present embodiment, SF ₆ gas which is a fluorine-containing gas is selected as the processing gas. FIG. 16 is a schematic view showing a reaction product generated in the chamber when the Mo-based material film is etched using SF ₆ gas as a processing gas. When plasma etching a Mo-based material film such as Mo film or MoW film using SF ₆ gas, as shown in FIG. 16, mainly MoF x is generated as a reaction product, and a part of these is on the chamber wall Although it adheres to a deposit (depot), MoFx has a high vapor pressure and can be removed by dry cleaning.

FIG. 17 is a schematic view showing a reaction product generated in the chamber when the Mo-based material film is etched using SF ₆ gas and O ₂ gas as a processing gas. On the other hand, when etching a Mo-based material film using SF ₆ gas and O ₂ gas as in the prior art, as shown in FIG. 17, MoFx Oy and MoO x as well as MoF x are also produced as reaction products. . Among these, MoOx does not volatilize because it has a low vapor pressure, and it easily adheres to the chamber wall and becomes a deposit (depot). And if MoOx which is a deposit peels off, it becomes a cause of a particle and exerts a bad influence on a product. Moreover, MoOx is difficult to remove by dry cleaning because it has high stability.

Therefore, in the present embodiment, MoFx capable of dry cleaning is generated as a reaction product in the chamber, and particles of the substrate S in the plasma etching apparatus 90 are not generated so as to cause generation of MoOx which is difficult to remove by dry cleaning. The processing gas is only the SF ₆ gas which is a fluorine-containing gas.

After selecting the processing gas at the time of plasma etching in this way, the plasma etching apparatus 90 performs plasma etching on the Mo material film formed on the substrate S using SF ₆ gas which is a processing gas selected in advance. Perform processing (step 12).

Hereinafter, the plasma etching process of step 12 will be specifically described.
The substrate S is taken out of the carrier 50 by the transport mechanism 60 and transported to the load lock chamber 20, and the vacuum transport mechanism 70 in the vacuum transport chamber 10 receives the substrate S from the load lock chamber 20 and transports the substrate S to the plasma etching apparatus 90.

  In the plasma etching apparatus 90, after the inside of the chamber 104 is adjusted to a pressure compatible with the vacuum transfer chamber 10, the gate valve G is opened, and the substrate S is loaded into the chamber 104 from the loading / unloading port 155 by the vacuum transfer mechanism 70, The substrate S is mounted on the substrate mounting table 130. After evacuating the vacuum transfer mechanism 70 from the chamber 104, the gate valve G is closed.

In this state, the pressure in the chamber 104 is adjusted to a predetermined degree of vacuum by the automatic pressure control valve (APC) 162, and the processing gas supply mechanism 220 is a fluorine-containing gas as the processing gas via the shower housing 111. SF ₆ gas is supplied into the chamber 104. In addition to the SF ₆ gas, an inert gas such as Ar gas may be supplied as a dilution gas.

  At this time, the substrate S is attracted by the electrostatic chuck 232 and temperature-controlled by a temperature control mechanism (not shown).

Next, a high frequency of 13.56 MHz, for example, is applied from the high frequency power source 115 to the high frequency antenna 113, thereby forming a uniform induction electric field in the chamber 104 via the dielectric wall 102. The induction electric field thus formed generates a plasma of SF ₆ gas which is a fluorine-containing gas. The Mo-based material film of the substrate S is etched by the high density inductively coupled plasma generated in this manner.

  At this time, in the plasma etching apparatus 90, MoFx is generated as a reaction product as described above, and adheres to a wall or the like in the chamber 104. On the other hand, MoOx is hardly generated.

  After the plasma etching process of step 12 is performed by the plasma etching apparatus 90, the substrate S is taken out by the vacuum transfer mechanism 70, transferred to the load lock chamber 20, and returned to the carrier 50 by the transfer mechanism 60.

  After the plasma etching process of step 12 as described above is performed one or two or more predetermined times, the dry cleaning process is performed in the chamber 104 of the plasma etching apparatus 90 (step 13).

In dry cleaning, in a state where the substrate S is not mounted on the substrate mounting table 130, SF ₆ gas which is a fluorine-containing gas is supplied as a dry cleaning gas into the chamber 104 as a dry cleaning gas. The same inductive coupling plasma as etching is used.

By this dry cleaning, MoFx attached to the chamber 104 of the plasma etching apparatus 90 can be removed. That is, since the plasma etching apparatus 90 does not contain the O ₂ gas conventionally used as the etching gas, MoO x which is difficult to remove by dry cleaning is not generated as a reaction product, and dry cleaning becomes possible.

Further, in dry cleaning, the substrate S is not mounted on the substrate mounting table 130, and the substrate S does not exist on the electrostatic chuck 232, so the plasma of SF ₆ gas which is a dry cleaning gas is directly electrostatic chucked. Acts on 232.

Conventionally, since dry cleaning is not performed in a plasma etching apparatus, plasma processing is not performed in a state in which the substrate S is not placed on the electrostatic chuck, and Y ₂ O ₃ or Al ₂ O as an insulating layer is used as an electrostatic chuck. It was sufficient to use W and Mo as an adsorption electrode using the sprayed film of No. ₃ . However, even if SF ₆ gas plasma, which is a fluorine-containing gas, acts directly on the electrostatic chuck during dry cleaning, the sprayed film of Y ₂ O ₃ or Al ₂ O ₃ which is an insulating layer has resistance, but thermal spraying When the sealing material of the film is removed by plasma and the plasma and fluorine-containing gas reach the adsorption surface, the adsorption electrode may be damaged by W or Mo, and the life of the electrostatic chuck may be shortened. found. In order to solve this problem, it is conceivable that dry cleaning is performed in a state where the raw glass which is a dummy substrate is mounted on the substrate mounting table 130 at the time of dry cleaning. In this case, the raw glass is used. A process of carrying in / out the plasma etching apparatus 90 occurs, and the productivity is reduced.

Therefore, in the present embodiment, a chromium-containing metal is used as the attraction electrode 246 of the electrostatic chuck 232. For example, in the present embodiment, chromium (Cr) is used as the adsorption electrode 246. Since Cr has higher resistance to plasma of SF ₆ gas which is a fluorine-containing gas than W and Mo, it is possible to maintain a desired life without mounting the raw glass at the time of dry cleaning.

In addition, a mixed sprayed film formed by spraying a mixture of alumina (Al ₂ O ₃ ), yttria (Y ₂ O ₃ ) and a silicon compound, and Y ₂ O ₃ is an SF ₆ gas that is a fluorine-containing gas. Since the resistance to plasma is high, the resistance to SF ₆ gas plasma can be further enhanced by using a mixed spray film or Y ₂ O ₃ as the insulating layer 245 in addition to using Cr as the adsorption electrode 246.

  As described above, after performing the plasma etching process (step 12) a predetermined number of times and repeating the dry cleaning (step 13) cycle, the deposits (deposits) deposited in the chamber 104 of the plasma etching apparatus 90 are peeled off. It will start to occur. Therefore, after repeating such a cycle a predetermined number of times, the chamber 104 is opened and chamber wet cleaning (step 14) is performed. The chamber wet cleaning is performed by wiping the deposit with alcohol, cleaning with a special chemical solution, or the like.

As described above, the plasma etching apparatus 30 performs a plasma etching process using plasma of a fluorine-containing gas. The adsorption electrode 246 is formed of a chromium-containing metal. For example, the adsorption electrode 246 is formed of chromium (Cr). Thereby, since the adsorption electrode 246 has resistance to the plasma of the fluorine-containing gas at the time of dry cleaning, the life of the electrostatic chuck 132 can be secured even if dry cleaning is performed. In addition, by using a mixed spray coating as the insulating layer 245 of the electrostatic chuck 232, the resistance to plasma of SF ₆ gas which is a fluorine-containing gas can be further enhanced.

Further, the processing system 100 etches the substrate S only with SF ₆ gas, which is a fluorine-containing gas, so that the reaction product generated in the etching processing by the plasma etching apparatus 90 can be dry-cleaned. And, it was made not to use O ₂ gas which was conventionally used together with SF ₆ gas. Therefore, in the plasma etching apparatus 90, MoOx having a low vapor pressure is not generated during the plasma etching process, and deposits (depots) generated in the chamber are only MoFx having a high vapor pressure. Therefore, in the plasma etching apparatus 90, the deposits (deposits) in the chamber are reduced as compared with the prior art, and the deposits (deposits) in the chamber can be removed by dry cleaning. As a result, the processing system 100 can significantly prolong the cycle of the chamber cleaning performed by opening the chamber of the plasma etching apparatus 90, that is, the maintenance cycle.

<Other application>
The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention. For example, in the above embodiment, the example applied to the etching of the Al-containing metal film for forming the source electrode and the drain electrode of the TFT and the etching of the Mo-based material film for forming the light shielding film or the gate electrode has been described. However, the present invention is not limited to this, as long as it is possible to use a processing gas which makes it possible to dry clean the reaction product generated in the plasma etching process in the plasma etching apparatus.

  In the above embodiment, an example in which the same etching gas as plasma etching is used is shown as the cleaning gas, but the cleaning gas may be different from the etching gas.

  Furthermore, although the example which used the inductive coupling plasma etching apparatus as a plasma etching apparatus was shown in the said embodiment, it is not only this but other plasma etching apparatuses, such as a capacitive coupling plasma etching apparatus and a microwave plasma etching apparatus. May be

Reference Signs List 1 glass substrate 2 light shielding layer 4 polysilicon film 5 gate insulating film 6 gate electrode 7 interlayer insulating film 8 a source electrode 8 b drain electrode 10 vacuum transfer chamber 20 load lock chamber 30, 90 plasma etching device 40 post-processing device 50 carrier 60 transfer mechanism 70 vacuum transfer mechanism 80 control unit 100, 200 processing system 101 main container 102 dielectric wall 104 chamber 111 shower case 113 high frequency antenna 115, 153 high frequency power supply 120, 120 ', 220 processing gas supply mechanism 130 substrate mounting table 131 substrate 132, 232 electrostatic chuck 145, 245 insulating layer 145a, 245a upper insulating layer 145b, 245b lower insulating layer 146, 246 adsorption electrode 160 exhaust portion S substrate

Claims (6)

An insulating layer which constitutes a mounting surface of a mounting table on which an object to be treated to be subjected to plasma processing is to be mounted, and which is formed of alumina, yttria and a silicon compound;
An adsorbing electrode which is provided in the insulating layer, is formed of a nickel-containing metal or a chromium-containing metal, and adsorbs the object by applying a predetermined voltage;
What is claimed is: 1. A plasma processing apparatus comprising: The plasma processing is plasma etching processing by plasma of chlorine-containing gas,
The plasma processing apparatus according to claim 1, wherein the adsorption electrode is formed of a nickel-containing metal. The plasma processing is plasma etching processing by plasma of fluorine-containing gas,
The plasma processing apparatus according to claim 1, wherein the adsorption electrode is formed of a chromium-containing metal. The plasma processing apparatus according to claim 2, wherein the adsorption electrode is formed of any one of Ni-5Al, SUS316L, and Hastelloy. The insulating layer is formed of an upper insulating layer on the side of the object to be treated with respect to the adsorption electrode and a lower insulating layer on the opposite side of the object to be treated with respect to the adsorption electrode, and only the lower insulating layer is sealed. The plasma processing apparatus according to any one of claims 1 to 4, wherein sealing treatment with a hole member is performed. The plasma processing apparatus according to any one of claims 1 to 5, further comprising a base material that supports the insulating layer and is formed of stainless steel.

Images