TWI767918B - Plasma etching method, plasma etching apparatus, and substrate stage - Google Patents

Abstract

Provide a plasma etching method that can be introduced into dry cleaning and can prolong the maintenance period of the processing vessel.

A plasma etching method for plasma etching a specific film of a substrate to be formed by a plasma etching device, comprising: in the plasma etching process of the plasma etching device, a process gas is selected so that a reaction product is generated A process capable of dry cleaning; in a plasma etching apparatus, a process of performing plasma etching treatment on a specific film using a pre-selected process gas; a process of performing plasma etching treatment once or twice or more After a certain number of times, the process of dry cleaning the chamber of the plasma etching device by the plasma of the dry cleaning gas.

Description

Plasma etching method, plasma etching apparatus, and substrate stage

The present invention relates to a plasma etching method, a plasma etching apparatus, and a substrate stage used therefor.

Thin Film Transistor (TFT: Thin Film Transistor) used in FPD (Flat Panel Display) is patterned on one side of a glass substrate, such as a gate electrode, a gate insulating film, a semiconductor layer, etc., and one side is sequentially formed by lamination.

When forming a TFT, there is, for example, a process of etching a source electrode or a drain electrode connected to a semiconductor layer, or a process of etching a gate electrode. A source electrode or a drain electrode may use an Al-containing metal film such as a laminated film of Ti/Al/Ti, and a chlorine-containing gas such as Cl ₂ gas is used as the etching gas in this case (for example, Patent Document 1) . In addition, as a countermeasure against corrosion by chlorine-containing gas, there are cases where chlorine-containing gas is used to supply O ₂ gas to the chamber after etching, or fluorine-based gas such as O ₂ gas and CF ₄ gas to perform corrosion inhibition treatment. .

Furthermore, as the gate electrode, there is a case where a film containing Mo is used, and as the etching gas in this case, a mixed gas of SF ₆ gas and O ₂ gas is used (for example, Patent Document 2).

However, when the etching process is repeated on a plurality of substrates, the reaction product adheres to the chamber and becomes a deposit (deposit), which peels off and becomes particles, which adversely affects the product. Use alcohol to wipe deposits, or use special chemical solution to clean the chamber (wet cleaning).

In addition, after etching the Al-containing metal film with chlorine-containing gas such as Cl ₂ gas as described above, the case where O ₂ gas and fluorine gas are supplied into the chamber, and the case where the Mo-containing film is etched with a mixed gas of SF ₆ gas and O ₂ gas In this case, since a large amount of reaction products with low vapor pressure, which are the cause of particles, are generated, they adhere to the chamber and become deposits (deposits), so the cycle of cleaning the chamber, that is, the maintenance cycle is shortened.

Therefore, in order to increase the maintenance cycle of the plasma etching apparatus, chamber cleaning (dry cleaning) for removing reaction products adhering to the chamber without opening the chamber by supplying a cleaning gas has been studied.

[Prior Art Literature] [Patent Documents]

[Patent Document 1] Japanese Patent Application Laid-Open No. 2015-173159

[Patent Document 2] Japanese Patent Application Laid-Open No. 2016-48286

However, it has been proved that the low vapor pressure reaction product generated by the plasma etching as described above cannot be effectively removed by dry etching. go.

Furthermore, when dry cleaning is performed without placing the substrate on the substrate mounting table, the electrostatic jig may be damaged by the plasma of the dry cleaning gas, and the lifetime may be shortened. Therefore, although it is considered that the plain glass is placed and dry cleaning is performed, in this case, the productivity is lowered.

Therefore, the present invention aims to provide a plasma etching method capable of introducing dry cleaning and prolonging the maintenance period of the processing container, and a plasma etching apparatus capable of ensuring the life of the electrostatic jig even if dry cleaning is performed, and use thereof. The substrate stage is a problem.

In order to solve the above-mentioned problems, a first aspect of the present invention is to provide a plasma etching method for plasma etching a specific film to be formed on a substrate by a plasma etching apparatus, characterized by comprising: In the plasma etching process of the above-mentioned plasma etching apparatus, a process gas is selected so that the produced reaction product can be dry-cleaned; in the above-mentioned plasma etching apparatus, the above-mentioned specific film is used. The process of processing gas to carry out plasma etching treatment; after the process of carrying out the above-mentioned plasma etching process is carried out one or more times for a specific number of times, the cavity of the above-mentioned plasma etching device is cleaned by the plasma of the dry cleaning gas. Indoor dry cleaning works.

In the plasma etching method according to the first aspect, as the dry cleaning gas in the dry cleaning, the same gas as the processing gas used in the plasma etching can be used.

The plasma etching method of the above-mentioned first aspect can be applied to the above-mentioned specific film being an Al-containing metal film, the above-mentioned processing gas being a chlorine-containing gas, the above-mentioned reaction product being AlClx, and further comprising performing the above-mentioned plasma etching in the above-mentioned plasma etching apparatus. After that, the processed substrate is transported to a post-processing device installed separately, and the post-processing process for corrosion inhibition is performed using O ₂ gas, or O ₂ gas and fluorine-containing gas. The above dry cleaning process can be applied to the The situation after the above-mentioned plasma etching process and the above-mentioned post-treatment process are performed once or twice for a specific number of times. In addition, Cl2 gas can be used as the said chlorine _- containing gas of the said process gas.

As the above-mentioned Al-containing metal film, a Ti/Al/Ti film for forming a source electrode and a drain electrode of a thin film transistor can be used.

The plasma etching method according to the first aspect can be applied to the case where the specific film is a Mo-based material film, the processing gas is a fluorine-containing gas, and the reaction product is MoFx. In addition, as the said fluorine-containing gas of the said process gas, _SF6 gas can be used.

As the Mo-based material film, a Mo film or a MoW film for forming a gate electrode or a light-shielding film of a thin film transistor can be used.

A second aspect of the present invention is to provide a plasma etching apparatus for subjecting a specific film formed on a substrate to a plasma etching process, comprising: a process container for accommodating the substrate; A substrate stage for placing a substrate in a container, a gas supply mechanism for supplying etching gas and dry cleaning gas into the processing container, an exhaust mechanism for evacuating the inside of the processing container, and generating the etching in the processing container A plasma generation mechanism for the plasma of the gas and the above-mentioned dry cleaning gas, the above-mentioned The substrate stage has a base material, is disposed on the base material, has a dielectric layer made of a ceramic spray film, and an electrostatic jig having an adsorption electrode disposed inside the dielectric layer, the dry cleaning gas For chlorine-containing gas, the above-mentioned dielectric layer of the above-mentioned electrostatic jig is a mixed spray film formed by spraying a mixture of aluminum oxide, yttrium oxide and silicon compound.

In the plasma etching apparatus according to the second aspect, it is preferable that the hybrid spray film of the dielectric layer constituting the electrostatic chuck is made of silicon oxide or silicon nitride as a silicon compound. As the said adsorption electrode of the said electrostatic clip, what consists of tungsten or molybdenum can be used. As the above-mentioned dry cleaning gas, Cl ₂ gas can be used.

A third aspect of the present invention is to provide a plasma etching apparatus for subjecting a specific film formed on a substrate to a plasma etching process, comprising: a process container for accommodating the substrate; A substrate stage for placing a substrate in a container, a gas supply mechanism for supplying etching gas and dry cleaning gas into the processing container, an exhaust mechanism for evacuating the inside of the processing container, and generating the etching in the processing container The plasma generation mechanism of the plasma of the gas and the dry cleaning gas, wherein the substrate mounting table has a base material, is provided on the base material, has a dielectric layer made of a ceramic spray film, and is provided on the above-mentioned base material. In the electrostatic jig of the adsorption electrode inside the dielectric layer, the dry cleaning gas is a fluorine-containing gas, and the adsorption electrode is made of aluminum.

In the plasma etching apparatus according to the third aspect, the dielectric layer of the electrostatic jig may be a mixed spray film formed by spraying a mixture of aluminum oxide, yttrium oxide and silicon compound, or may be formed of yttrium oxide By. As the above-mentioned dry cleaning gas, SF ₆ gas can be used.

In the plasma etching apparatus of the above-mentioned second and third viewpoints, the same gas as the above-mentioned dry cleaning gas can be used as the above-mentioned etching gas.

A fourth aspect of the present invention is to provide a substrate stage in which a specific film formed on a substrate is subjected to plasma etching with an etching gas in a processing container, and the plasma of a dry cleaning gas is used to etch a specific film. In the plasma etching apparatus for dry cleaning in the above-mentioned processing container, a substrate is placed in the above-mentioned processing container, and the substrate mounting table is characterized by having a base material, being provided on the base material, and having a surface formed by ceramic spraying. A dielectric layer composed of a film and an electrostatic jig with an adsorption electrode disposed inside the dielectric layer, the dry cleaning gas is a chlorine-containing gas, and the dielectric layer of the electrostatic jig is a fusion-sprayed aluminum oxide and yttrium oxide. Hybrid spray film formed with a mixture of silicon compounds.

A fifth aspect of the present invention is to provide a substrate stage in which a specific film formed on a substrate is subjected to plasma etching with an etching gas in a processing container, and the plasma of a dry cleaning gas is used to etch a specific film. In the plasma etching apparatus for dry cleaning in the above-mentioned processing container, a substrate is placed in the above-mentioned processing container, and the substrate mounting table is characterized by having a base material, being provided on the base material, and having a surface formed by ceramic spraying. The electrostatic jig including the dielectric layer and the adsorption electrode provided inside the dielectric layer, the dry cleaning gas is a fluorine-containing gas, and the adsorption electrode of the electrostatic jig is made of aluminum.

According to the present invention, in the plasma etching process of the plasma etching apparatus, the process gas is selected so that the generated reaction product can be dry cleaned, and the maintenance period of the process container can be extended after the plasma etching process. .

Since the electrostatic jig can be constructed with high resistance to chlorine-containing plasma or fluorine-containing plasma, the life of the electrostatic jig can be ensured even if dry cleaning is performed.

1: glass substrate

2: shading layer

4: Polysilicon film

5: Gate insulating film

6: Gate electrode

7: Interlayer insulating film

8a: source electrode

8b: drain electrode

10: Vacuum transfer room

20: Load lock chamber

30, 90: Plasma etching device

40: Aftertreatment device

50: carrier

60: Handling mechanism

70: Vacuum transfer mechanism

80: Control Department

100, 200: Processing system

101: Handling Containers

102: Dielectric Wall

104: Chamber

111: Spray frame

113: high frequency antenna

115: High frequency power supply

120, 120', 220: Process gas supply mechanism

130: Substrate stage

132, 232: electrostatic clamp

145, 245: Dielectric layer

146, 246: adsorption electrode

160: Exhaust mechanism

S: substrate

FIG. 1 is a cross-sectional view showing the structure of a substrate 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 in the processing system of FIG. 2 .

FIG. 4 is a schematic diagram showing a processing apparatus after being installed in the processing system of FIG. 2 .

FIG. 5 is a flowchart of a plasma processing method related to the first embodiment.

6 is a schematic view showing a reaction product generated in a chamber when the Al-containing metal film is etched using Cl ₂ gas as a processing gas.

FIG. 7 shows the reaction products generated in the chamber when the Al-containing metal film is etched using Cl ₂ gas as the processing gas, and then post-processing is performed using O ₂ gas, or O ₂ gas and CF ₄ gas. Sketch map.

FIG. 8 is a schematic plan view showing a processing system for implementing the processing method of the second embodiment.

FIG. 9 is a cross-sectional view showing a plasma etching apparatus mounted in the processing system of FIG. 8 .

FIG. 10 is a flowchart of a plasma processing method related to the second embodiment.

11 is a schematic view showing a reaction product generated in a chamber when the Mo-based material film is etched using SF ₆ gas as a processing gas.

12 is a schematic view showing a reaction product generated in a chamber when the Mo-based material film is etched using SF ₆ gas and O ₂ gas as processing gases.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings.

[The structure of the substrate to which the plasma processing method related to the embodiment of the present invention is applied]

FIG. 1 is a cross-sectional view showing the structure of a substrate to which a plasma processing method according to an embodiment of the present invention is applied.

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

[First Embodiment]

First, the first embodiment will be described.

In the first embodiment, the etching process of the Al-containing metal film at the time of forming the source electrode 8a and the drain electrode 8b of the substrate S shown in FIG. 1 will be described as an example. In addition, during the etching of the Al-containing metal film for forming the source electrode 8a and the drain electrode 8b, a resist film (not shown) having a specific pattern is formed thereon, and this is masked to conduct electricity. slurry etching.

(Apparatus configuration for processing system, plasma etching apparatus, etc. of the first embodiment)

First, for the processing system and plasma etching used in the first embodiment The device configuration of the device and the like will be described.

2 is a schematic plan view showing a processing system for carrying out the processing method of the first embodiment, FIG. 3 is a cross-sectional view showing a plasma etching apparatus mounted in the processing system of FIG. 2 , and FIG. 4 is a The schematic diagram of the processing apparatus after the processing system of FIG. 2 is shown.

As shown in FIG. 2 , the processing system 100 is a multi-chamber type processing system having a vacuum transfer chamber 10 , a load lock chamber 20 , two plasma etching apparatuses 30 and a post-processing apparatus 40 . The plasma etching apparatus 30 and the post-processing apparatus 40 perform processing under a specific reduced pressure atmosphere. The top view shape of the vacuum transfer chamber 10 is rectangular, and the load lock chamber 20 , the two plasma etching apparatuses 30 , and the post-processing apparatus 40 are connected to the respective walls of the vacuum transfer chamber 10 via the gate valve G. On the outside of the load lock chamber 20, a carrier 50 for accommodating the rectangular substrate S is arranged.

Between the two carriers 50, a conveying mechanism 60 is provided, and the conveying mechanism 60 has a pickup 61 (only one is shown in the figure) arranged in two upper and lower stages, and can be integrated with the two carriers 50 to enter, exit, and retract. Rotating base 62 .

The vacuum transfer chamber 10 can be maintained in a specific reduced pressure atmosphere, and as shown in FIG. 2 , a vacuum transfer mechanism 70 is provided. Then, the substrate S is conveyed between the load lock chamber 20 , the two plasma etching apparatuses 30 , and the post-processing apparatus 40 by the vacuum conveyance mechanism 70 . The vacuum conveyance mechanism 70 is attached to a base 71 which can be rotated and moved up and down, and two substrate conveyance arms 72 (only one is shown in the figure) are provided so as to be able to move back and forth.

The load lock chamber 20 is used for the carrier in the atmospheric atmosphere 50 and the vacuum transfer chamber 10 in a decompressed atmosphere, the recipient and the receiver of the substrate S can be switched between the vacuum atmosphere and the atmospheric atmosphere in a short time. In the load lock chamber 20 , the substrate accommodating portion is provided in two upper and lower steps, and in each substrate accommodating portion, the substrate S is aligned by a positioner (not shown).

The plasma etching apparatus 30 is used to etch the Al-containing metal film of the substrate S, and as shown in FIG. 3 , for example, has an airtight main container 101 in the shape of a square tube made of aluminum whose inner wall surface is anodized. The body container 101 is assembled to be disassembled and grounded. The main body container 101 is divided into upper and lower sections by the dielectric wall 102, the upper side becomes the antenna container 103 which partitions the antenna chamber, and the lower side becomes the chamber (processing container) 104 which partitions the processing chamber. The dielectric wall 102 constitutes the top wall of the chamber 104 and is composed of ceramics such as Al ₂ O ₃ , quartz or the like.

Between the side wall 103a of the antenna container 103 in the main body container 101 and the side wall 104a of the cavity 104, a support frame 105 protruding inside is provided, and the dielectric wall 102 is placed on the support frame 105.

A shower frame 111 for supplying a process gas is embedded in the lower portion of the dielectric wall 102 . The shower frame 111 is provided in a cross shape, and has a beam structure that supports the dielectric wall 102 from below. The shower frame 111 is in a state of being suspended from the ceiling of the main body container 101 by a plurality of hanging rods (not shown).

The shower frame 111 is made of conductive material, such as aluminum whose inner surface or outer surface is anodized. A gas flow path 112 extending horizontally is formed in the shower frame 111 , and a plurality of gas discharge holes 112 a extending downward are continuous in the gas flow path 112 .

In addition, a gas supply pipe 121 is provided in 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 branches to branch pipes 121a and 121b. The branch pipe 121a is connected to a chlorine-containing gas supply source 122 for supplying chlorine-containing gas, such as Cl ₂ gas. Further, the branch pipe 121b is connected to an inert gas supply source 123 that supplies inert gas such as Ar gas and N ₂ gas used as flushing gas or diluent gas. Chlorine-containing gas is used as etching gas and dry cleaning gas. A flow controller such as a mass flow controller or a valve system is provided in the branch pipes 121a and 121b.

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

In the plasma etching apparatus 30, the chlorine-containing gas supplied from the process gas supply mechanism 120 is supplied into the shower frame 111, and is discharged into the chamber 104 from the gas discharge hole 112a on the lower surface, and the substrate S is discharged into the chamber 104. Etching of Al-containing metal films or dry cleaning of the chamber 104 . As the chlorine-containing gas, chlorine (Cl ₂ ) gas is preferable, but boron trichloride (BCl ₃ ) gas, carbon tetrachloride (CCl ₄ ) gas, or the like can also be used.

A high frequency (RF) antenna 113 is arranged in the antenna container 103 . The high-frequency antenna 113 is configured by arranging an antenna 113a made of a metal with good conductivity such as copper or aluminum in an arbitrary shape conventionally used, such as a ring shape or a spiral shape. Even a multi-antenna having a plurality of antenna sections may be used. The high frequency antenna 113 is spaced from the dielectric wall 102 by spacers 117 formed by insulating members.

A power supply member 116 extending above the antenna container 103 is connected to the terminal 118 of the antenna 113a. A power supply line 119 is connected to the upper end of the power supply member 116 , and the matching device 114 and the high-frequency power supply 115 are connected to the power supply line 119 . Then, by supplying high-frequency power with a frequency of, for example, 13.56 MHz from the high-frequency power supply 115 to the high-frequency antenna 113, an induced electric field is formed in the chamber 104, and the processing gas supplied from the shower casing 111 is caused by the induced electric field. Plasma is generated to generate inductively coupled plasma.

On the bottom wall in the chamber 104, a substrate mounting table 130 on which the substrate G is mounted is provided with a frame-shaped spacer 134 made of insulating property interposed therebetween. The substrate stage 130 includes a base material 131 provided on the spacer 134 , an electrostatic chuck 132 provided on the base material 131 , and a sidewall insulating member 133 covering the sidewalls of the base material 131 and the electrostatic chuck 132 . The base material 131 and the electrostatic chuck 132 are formed in 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 ceramics such as alumina.

The electrostatic chuck 132 has a dielectric layer 145 formed of a ceramic spray film formed on the surface of the base material 131 , and a suction electrode 146 provided inside the dielectric layer 145 . The adsorption electrode 146 can take various shapes such as plate shape, film shape, lattice shape, and mesh shape. A DC power supply 148 is connected to the suction electrode 146 via a power supply line 147 , and a DC voltage is applied to the suction electrode 146 . The power supply to the suction electrode 146 is turned on and off by a switch (not shown). The substrate S is attracted by applying a DC voltage to the attracting electrode 146 to generate electrostatic attracting force such as the Coulomb force or the Johnson & Johnson Rabeck force.

The dielectric layer 145 of the electrostatic clamp 132 is formed of a mixed spray film. The mixed spray film is formed by spraying a mixture of aluminum oxide (Al ₂ O ₃ ) and yttrium oxide (Y ₂ O ₃ ) and a silicon compound. Due to the high plasma resistance of Y ₂ O ₃ material, in addition, Al ₂ O ₃ has high chemical resistance to chlorine-containing gas, and the silicon compound has the grain boundary that becomes glassy to bury Y ₂ O ₃ and Al ₂ O ₃ Because of the effect of densification, the mixed spray film has high resistance to plasma of chlorine-containing gas such as Cl ₂ gas. As the mixed spray film, silicon oxide (SiO ₂ ), and Al ₂ O ₃ , Y ₂ O ₃ , and SiO ₂ films which are silicon compounds are preferably used.

Furthermore, Al ₂ O ₃ , Y ₂ O ₃ , SiO ₂ , and Si ₃ N ₄ films using silicon nitride (Si ₃ N ₄ ) as the silicon compound can also be suitably used. The adsorption electrode 146 of the electrostatic clamp 132 is made of tungsten (W) or molybdenum (Mo) which has been used in the past. These have high resistance to plasma containing chlorine gas.

A high-frequency power supply 153 for applying a bias voltage is connected to the base material 131 via a power supply line 151 . Furthermore, a matching device 152 is provided between the base material 131 of the power supply line 151 and the high-frequency power supply 153 . The high-frequency power source 153 is used for pulling ions into the substrate S on the base material 131 , and uses a frequency in the range of 50 kHz to 10 MHz, for example, 3.2 MHz.

Moreover, in the base material 131 of the board|substrate mounting table 130, the temperature adjustment mechanism and temperature sensor (neither of which are not shown) for controlling the temperature of the board|substrate S are provided. Furthermore, in the state where the substrate S is placed on the substrate stage 130 , a heat-conducting gas supply mechanism (not shown) for supplying He gas, such as He gas, is provided for heat transfer between the substrate S and the substrate stage 130 . Furthermore, on the substrate mounting table 130, the electrostatic chuck 132 can be The upper surface is recessed, and a plurality of lift pins (not shown) are provided for receiving and transferring the substrate S. The receiving and transferring of the substrate S is performed on the lift pins protruding from the upper surface of the electrostatic clamp 132 to the upper side.

The side wall 104a of the chamber is provided with a loading/unloading port 155 for loading/unloading the substrate S to/from 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 substrate S can be loaded and unloaded through the loading and unloading port 155 according to the vacuum transport mechanism 70 installed in the vacuum transport chamber 10 .

A plurality of exhaust ports 159 (only two are shown) are formed at the edge or corner of the bottom wall of the chamber 104 , and an exhaust portion 160 is provided in each of the exhaust ports 159 . The exhaust part 160 has an exhaust pipe 161 connected to the exhaust port 159, an automatic pressure control valve (APC) 162 for controlling the pressure in the chamber 104 by adjusting the opening degree of the exhaust pipe 161, and a A vacuum pump 163 for evacuating the inside of the chamber 104 through the exhaust pipe 161 . Furthermore, the chamber 104 is evacuated by the vacuum pump 163, and during the plasma etching process, the opening degree of the automatic pressure control valve (APC) 162 is adjusted to set and maintain the chamber 104 in a specific vacuum atmosphere.

The post-processing device 40 is used to perform post-processing for inhibiting corrosion after etching the Al-containing metal film of the substrate S. FIG. As shown in FIG. 4 , 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 in place of the processing gas supply mechanism 120. Although other configurations are omitted in FIG. 4 , the configurations are the same as those of the plasma etching apparatus 30 . In addition, in the following description, the same code|symbol is attached|subjected to the same member as the plasma etching apparatus 30, and will be demonstrated.

The processing gas supply mechanism 120' of the post-processing device 40 has a gas supply pipe 121', branch pipes 121a', 121b', 121c' branched from the gas supply pipe 121' above and outside the main body container 101, and connected to the branch pipes 121a', 121b', 121c'. The _O2 gas supply source 124 for supplying _O2 gas to the pipe 121a', and the fluorine-containing gas supply source 125 for supplying the fluorine-containing gas connected to the branch pipe 121b', and the supply connected to the branch pipe 121c' as flushing gas Or the inert gas supply source 126 of the inert gas such as Ar gas, N ₂ gas or the like as a dilution gas. The gas supply pipe 121 ′ is the same as the gas supply pipe 121 of the plasma etching apparatus 30 , and is connected to the gas flow path 112 of the shower frame 111 (see FIG. 3 ). A flow controller such as a mass flow controller or a valve system is provided in the branch pipes 121a', 121b', and 121c'.

In the post-processing device 40 , the O ₂ gas supplied from the processing gas supply mechanism 120 ′, or the O ₂ gas and the fluorine-containing gas are discharged into the chamber 104 through the shower frame 111 , and the etching of the substrate S is performed. Then the corrosion inhibition treatment of the Al-containing metal film. As the fluorine-containing gas, although carbon tetrafluoride (CF ₄ ) can be suitably used, sulfur hexafluoride (SF ₆ ) or the like can also be used.

In addition, in the post-processing device 40, since the dielectric layer 145 of the electrostatic jig 132 is not required to be resistant to plasma by chlorine-containing gas, it can be made of Al ₂ O ₃ or Y ₂ O ₃ as in the past. The sprayed film constitutes the dielectric layer 145 . In addition, since the post-processing apparatus 40 performs only a corrosion suppression process, it is not necessary to provide the electrostatic jig 132.

The processing system 100 further includes a control unit 80 . The control unit 80 is composed of a computer including a CPU and a memory unit, and processes the components of the system 100 (the vacuum transfer chamber 10 , the load lock chamber 20 , the plasma etching device 30. The components of the post-processing device 40, the conveying mechanism 60, and the vacuum conveying mechanism 70) are controlled to perform specific processing according to the processing recipe (program) stored in the memory. The processing recipe is stored in a storage medium such as a hard disk, an optical disc, a semiconductor memory, or the like.

(Plasma treatment method related to the first embodiment)

Next, the plasma processing method related to the first embodiment of the processing system 100 described above will be described with reference to the flowchart of FIG. 5 .

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

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

Specifically, in this embodiment, a chlorine-containing gas such as Cl ₂ gas is selected as the processing gas. In the case of plasma etching the Ti/Al/Ti film using a chlorine-containing gas, as shown in FIG. 6 , AlClx is mainly formed as a reaction product, although a part of these adheres to the chamber wall and becomes a deposit (adhered to material), but AlClx has a high vapor pressure and can be removed by dry cleaning.

In addition, as in the past, after etching the Ti/Al/Ti film with Cl ₂ gas, and performing post _- treatment for corrosion inhibition in the same chamber, as shown in FIG. During the plasma treatment, the adhered AlClx reacts with the O ₂ gas to generate AlOx with a low vapor pressure in the chamber. Furthermore, in order to further improve the corrosion inhibition effect, in addition to the O ₂ gas, a fluorine-containing gas such as CF ₄ is supplied. In the case of gas, in addition to AlOx, AlFx with a low vapor pressure is also generated in the chamber. Since these AlOx and AlFx have a low vapor pressure, they do not volatilize, and they adhere to the chamber wall and tend to become deposits (deposits). Furthermore, when this peeling off, it becomes a cause of fine particles and has a bad influence on the product. Furthermore, since these are highly stable, they are difficult to remove by dry cleaning.

Therefore, in the present embodiment, in the chamber, AlClx that can be dry cleaned is generated as a reaction product, so that AlOx and AlFx, which are the cause of fine particles and are difficult to be removed by dry cleaning, are not generated. The processing gas of the substrate S in the plasma etching apparatus 30 is set to be only the etching gas, that is, the chlorine-containing gas (Cl ₂ gas).

In this way, after the process gas at the time of plasma etching is selected, the process gas selected in advance is used by the plasma etching apparatus 30 for the Al-containing metal film formed on the substrate S, that is, the Ti/Al/Ti film. That is, a chlorine-containing gas, such as Cl ₂ gas, is applied to the plasma etching process (step 2).

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

The substrate S is taken out from the carrier 50 by the transfer mechanism 60 and transferred to the load lock chamber 20 . The vacuum transfer mechanism 70 in the vacuum transfer chamber 10 receives the substrate S from the load lock chamber 20 and transfers it to the plasma etching apparatus 30 .

In the plasma etching apparatus 30 , first, the pressure in the chamber 104 is adjusted to be suitable for the vacuum transfer chamber 10 by the vacuum pump 163 , the gate valve G is opened, and the substrate S is transferred from the transfer port 155 to the vacuum transfer mechanism 70 . Inside the chamber 104 , the substrate S is placed on the substrate stage 130 . After the vacuum conveyance mechanism 70 is retracted from the chamber 104, the gate valve G is closed.

In this state, the pressure in the chamber 104 is adjusted to a specific degree of vacuum by the automatic pressure control valve (APC) 162, and the etching gas as the processing gas is also supplied from the processing gas supply mechanism 120 through the shower frame 111. That is, a chlorine-containing gas, such as 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 adsorbed by the electrostatic chuck 132, and its temperature is adjusted by a temperature adjustment mechanism (not shown).

Next, a high frequency such as 13.56 MHz is applied to the high frequency antenna 113 from the high frequency power supply 115 , thereby forming a uniform induced electric field in the cavity 104 through the dielectric wall 102 . Plasma containing chlorine gas is generated by the induced electric field thus formed. The Al-containing metal film of the substrate S, that is, the Ti/Al/Ti film, is etched by the thus-generated high-density inductively coupled plasma.

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

Next, for the Al-containing metal film of the substrate S after plasma etching, that is, the Ti/Al/Ti film, the post-processing device 40 uses O ₂ gas, or O ₂ gas and fluorine-containing gas, such as CF ₄ gas , and post-treatment for corrosion inhibition is performed (step 3).

Hereinafter, the specificity of the processing after step 3 will be described.

The substrate S after the etching process is taken out from the plasma etching apparatus 30 by the vacuum conveyance mechanism 70 and conveyed 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, placed on the substrate stage 130, and the pressure in the chamber 104 is adjusted to a predetermined degree of vacuum, O ₂ gas, or O ₂ gas and fluorine-containing gas, such as CF ₄ gas, are supplied into the chamber 104 from the processing gas supply mechanism 120 ′ through the shower frame 111 as the post-processing gas. In addition to these, an inert gas such as Ar may be supplied as a dilution gas.

Also, as in the plasma etching apparatus 30, by the induced electric field, O ₂ gas, which is the post-processing gas, or plasma of the O ₂ gas and the fluorine-containing gas is generated, and the inductively coupled plasma thus generated is subjected to annealing. Corrosion inhibition treatment of the etched Al-containing metal film, that is, the Ti/Al/Ti film.

At this time, in the post-processing apparatus 40, since the etching process is not performed, the generation amount of the reaction product is small.

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

After performing the above-mentioned plasma etching process (step 2) and post-processing (step 3) for a specific number of times or more, the dry cleaning process in the chamber 104 of the plasma etching apparatus 30 is performed (step 4) .

The dry cleaning is a state in which the substrate S is not placed on the substrate mounting table 130 , and the chamber 104 is supplied with a chlorine-containing gas such as Cl ₂ gas as the dry cleaning gas, which is the same as the etching gas used in the plasma etching. , by the same inductively coupled plasma as in the plasma etching.

By this dry cleaning, AlClx adhering to the chamber 104 of the plasma etching apparatus 30 can be removed. That is, in the plasma etching apparatus 30, since the conventional O ₂ gas, or the corrosion inhibition treatment by the O ₂ gas and the fluorine-containing gas is not performed, the reaction product is not generated by dry cleaning. AlOx and AlFx, which are difficult to remove, can be dry cleaned.

Furthermore, during the dry cleaning, since the substrate S is not placed on the substrate mounting table 130 and the substrate S does not exist on the electrostatic chuck 132, the dry cleaning gas, that is, the plasma containing chlorine gas directly acts on the static electricity. Clamp 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 jig, and the dielectric layer of the electrostatic jig is made of Y ₂ O ₃ or Al ₂ O ₃ of the spray film is sufficient. However, it has been confirmed that if the plasma containing chlorine gas acts directly during dry cleaning, damage will be caused to the spray film whose dielectric layer is Y ₂ O ₃ or Al ₂ O ₃ , and there is a possibility of shortening its life. . In order to solve this problem, in consideration of dry cleaning, dry cleaning is performed in a state where the dummy substrate, ie, plain glass, is mounted on the substrate mounting table 130 . In the process of moving out plain glass, productivity decreased.

Therefore, in this embodiment, as the dielectric layer 145 of the electrostatic clamp 132, a mixed spray film formed by spraying a mixture of Al ₂ O ₃ and Y ₂ O ₃ and a silicon compound is used. Due to the high plasma resistance of Y ₂ O ₃ material, in addition, Al ₂ O ₃ has high chemical resistance to chlorine-containing gas, and the silicon compound has the grain boundary that becomes glassy to bury Y ₂ O ₃ and Al ₂ O ₃ Due to the effect of densification, the mixed spray film has high resistance to plasma of chlorine-containing gas such as Cl ₂ gas, and can maintain the expected life without placing plain glass during dry cleaning.

As described above, as the mixed spray film, Al ₂ O ₃ , Y ₂ O ₃ and SiO ₂ films are preferable. In addition, Al ₂ O ₃ , Y ₂ O ₃ , SiO ₂ , and Si ₃ N ₄ films can also be suitably used. The adsorption electrode 146 of the electrostatic jig 132 exhibits high resistance to plasma of chlorine-containing gas by using tungsten (W) or molybdenum (Mo) which has been conventionally used.

In fact, for Al ₂ O ₃ and mixed spray films (Al ₂ O ₃ , Y ₂ O ₃ , SiO ₂ ), the cutting amount with respect to the plasma of chlorine-containing gas, that is, Cl ₂ gas was compared. As a result, it was confirmed that the cutting amount normalized by taking the cutting amount of the mixed spray film as 1 was 9 in Al ₂ O ₃ , and it was confirmed that the mixed spray film had high resistance to plasma containing chlorine gas.

In this way, after performing the plasma etching process (step 2) and post-processing (step 3) for a certain number of times, when the cycle of dry cleaning (step 4) is repeated, it adheres to the chamber of the plasma etching device 30 The deposits (attachments) in 104 begin to peel off. Therefore, after repeating this cycle for a certain number of times, the chamber 104 is opened for chamber cleaning (step 5). Chamber cleaning is performed by wiping off deposits with alcohol or cleaning with a special chemical solution.

As described above, in the present embodiment, in the etching process of the plasma etching apparatus 30, the process gas for processing the substrate S is used only as the etching gas so that the reaction product generated can be dry-cleaned. That is, chlorine-containing gas such as Cl ₂ gas is used in the post-processing device 40 provided separately to perform the O ₂ gas used for corrosion inhibition in the same chamber after etching in the past, or it is caused by O ₂ gas and fluorine-containing gas. Plasma treatment. Therefore, during the plasma etching process, AlOx and AlFx with a low vapor pressure are not generated, and the deposits (adhesion) generated in the chamber are only AlClx with a high vapor pressure. Therefore, the deposits (attachments) in the chamber itself are reduced compared to the conventional ones, and the deposits (attachments) in the chamber can be removed by dry cleaning, and the chamber cleaning by opening the chamber can be significantly increased The cycle is the maintenance cycle.

Furthermore, since the dielectric layer 145 of the electrostatic jig 132 in the plasma etching apparatus 30 is resistant to chlorine-containing plasma during dry cleaning, the life of the electrostatic jig can be ensured even if dry cleaning is performed.

[Second Embodiment]

Next, the second embodiment will be described.

In the present embodiment, the etching process of the Mo-based material film when the gate electrode 6 or the light shielding layer 2 of the substrate S shown in FIG. 1 is formed will be described as an example. In addition, during the etching of the Mo-based material film used to form the gate electrode 6 or the light shielding layer 2, a resist film (not shown) having a specific pattern is formed thereon, and this is masked to perform plasma etching.

(Apparatus configuration for processing system, plasma etching apparatus, etc. of the second embodiment)

First, the apparatus structure used for the processing system and the plasma etching apparatus etc. of 2nd Embodiment is demonstrated.

FIG. 8 shows a processing system for implementing the processing method of this embodiment. FIG. 9 is a schematic plan view of the system, and FIG. 9 is a cross-sectional view showing a plasma etching apparatus mounted in the processing system of FIG. 8 .

As shown in FIG. 8 , the processing system 200 is constructed as a multi-chamber type processing system substantially the same as the processing system 100 of FIG. 2 . The processing system 200 of this embodiment has two plasma etching apparatuses 30 and three plasma etching apparatuses 90 instead of the post-processing apparatus 40 , and has the same structure as the processing system 100 of FIG. 2 . Since other structures are the same as those in FIG. 2 , the same reference numerals are assigned to them, and the description thereof will be omitted.

The plasma etching apparatus 90 is used for etching the Mo-based material film of the substrate S. As shown in FIG. In addition, it has the same structure as the plasma etching apparatus 30 of FIG. Therefore, the same reference numerals are given to the same elements as those in FIG. 3 , and descriptions thereof are omitted.

The processing gas supply mechanism 220 includes a gas supply pipe 221, branch pipes 221a and 221b branched from the gas supply pipe 221 above and outside the main body container 101, and _SF6 for supplying fluorine-containing gas, that is, _SF6 gas, which is connected to the branch pipe 221a. The gas supply source 222 and the inert gas supply source 223 for supplying Ar gas, N ₂ gas, etc. connected to the branch pipe 221b are used as flushing gas or diluting gas. The gas supply pipe 221 is the same as the gas supply pipe 121 of the plasma etching apparatus 30 in FIG. 3 , and is connected to the gas flow path 112 of the shower frame 111 . The fluorine-containing gas is used as etching gas and dry cleaning gas. In addition, in addition to SF ₆ gas, CF ₄ or NF ₃ can also be used as the fluorine-containing gas.

The electrostatic chuck 232 has a surface formed on the substrate 131 A dielectric layer 245 made of a ceramic spray film, and an adsorption electrode 246 provided inside the dielectric layer 245 . The adsorption electrode 246 can take various shapes such as plate shape, film shape, lattice shape, and mesh shape. The DC power supply 148 is connected to the suction electrode 246 via the power supply line 147 , and a DC voltage is applied to the suction electrode 246 . The power supply to the suction electrode 246 is turned on and off by a switch (not shown). The substrate S is attracted by applying a DC voltage to the attracting electrode 246 to generate electrostatic attracting force such as the Coulomb force or the Johnson-Rabecque force.

The dielectric layer 245 of the electrostatic clamp 232 is composed of a mixed spray film formed by spraying a mixture of aluminum oxide (Al ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ) and a silicon compound, or Y ₂ O ₃ . Furthermore, the adsorption electrode 246 of the electrostatic clamp 232 is made of aluminum (Al). A mixture of aluminum oxide (Al ₂ O ₃ ) and yttrium oxide (Y ₂ O ₃ ) and a silicon compound constituting the dielectric layer 245 , and Y ₂ O ₃ , and Al constituting the adsorption electrode 246 relative to a fluorine-based gas, that is, SF Plasma of ₆ has high resistance.

(Plasma treatment method related to the second embodiment)

Next, the plasma processing method related to the second embodiment of the processing system 200 described above will be described with reference to the flowchart of FIG. 10 .

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

Initially, in the etching process of the plasma etching apparatus 90, a process gas is selected so that the reaction product produced 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. When using SF ₆ gas to plasma-etch a Mo film or a Mo-based material film such as a MoW film, as shown in FIG. 11 , MoFx is mainly generated as a reaction product, although a part of these adheres to the chamber wall and It becomes a deposit (deposition), but MoFx has a high vapor pressure and can be removed by dry cleaning.

In addition, when the Mo-based material film is etched using SF ₆ gas and O ₂ gas in the conventional manner, as shown in FIG. 12 , MoFxOy or MoOx is produced as a reaction product in addition to MoFx. Among these, MoOx does not volatilize due to its low vapor pressure, and adheres to the chamber wall to easily become a deposit (adhesion). Furthermore, when MoOx, which is a deposit, is peeled off, it becomes a cause of fine particles and adversely affects the product. Furthermore, since MoOx has high stability, it is difficult to remove it by dry cleaning.

Therefore, in this embodiment, in the chamber, MoFx that can be dry-cleaned is generated as a reaction product, so that MoOx, which is a cause of particles and is difficult to be removed by dry-cleaning, is not generated in the chamber. The processing gas for the substrate S in the plasma etching apparatus 90 is only SF ₆ gas, which is a fluorine-containing gas.

In this way, after the process gas at the time of plasma etching is selected, the Mo material film formed on the substrate S is subjected to plasma by the plasma etching apparatus 90 using the pre-selected process gas, that is, SF ₆ gas. Etching process (step 12).

Hereinafter, the specificity of the plasma etching process in step 12 will be described.

The substrate S is taken out from the carrier 50 by the transfer mechanism 60 and transferred to the load lock chamber 20 . The vacuum transfer mechanism 70 in the vacuum transfer chamber 10 receives the substrate S from the load lock chamber 20 and transfers it to the plasma etching apparatus 90 .

In the plasma etching apparatus 90, after the pressure in the chamber 104 is adjusted to be suitable for the vacuum transfer chamber 10, the gate valve G is opened to carry the substrate S into the chamber 104 from the transfer port 155 by the vacuum transfer mechanism 70, The substrate S is placed on the substrate placing table 130 . After the vacuum conveyance mechanism 70 is retracted from the chamber 104, the gate valve G is closed.

In this state, the pressure in the chamber 104 is adjusted to a specific degree of vacuum by the automatic pressure control valve (APC) 162, and the fluorine-containing gas as the processing gas is supplied from the processing gas supply mechanism 220 through the shower frame 111 at the same time. That is, SF ₆ gas is supplied into the chamber 104 . In addition to 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 its temperature is adjusted by a temperature adjustment mechanism (not shown).

Next, a high frequency such as 13.56 MHz is applied to the high frequency antenna 113 from the high frequency power supply 115 , thereby forming a uniform induced electric field in the cavity 104 through the dielectric wall 102 . By the induced electric field thus formed, a plasma of fluorine-containing gas, that is, SF ₆ gas is generated. The Mo-based material film of the substrate S is etched by the high-density inductively coupled plasma thus generated.

At this time, in the plasma etching apparatus 90, as described above, MoFx is generated as a reaction product, and adheres to the wall and the like in the chamber 104. In addition, almost no MoOx is generated.

The plasma etching in step 12 is performed by the plasma etching apparatus 90 After the processing, 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 above-mentioned plasma etching process in step 12 is performed once or twice for a specific number of times, the dry cleaning process in the chamber 104 of the plasma etching apparatus 90 is performed (step 13 ).

The dry cleaning is a state in which the substrate S is not placed on the substrate mounting table 130 , and the chamber 104 is supplied with a fluorine-containing gas, that is, SF ₆ gas as the etching gas used in the plasma etching, as the dry cleaning. Gas, by the same inductively coupled plasma as in the plasma etching.

By this dry cleaning, MoFx adhering to the chamber 104 of the plasma etching apparatus 90 can be removed. That is, in the plasma etching apparatus 90, since the O ₂ gas conventionally used is not contained as the etching gas, as a reaction product, MoOx, which is difficult to be removed by dry cleaning, is not generated as a reaction product, and dry cleaning is possible.

Furthermore, during the dry cleaning, since the substrate S is not placed on the substrate mounting table 130 and the substrate S does not exist on the electrostatic chuck 232, the dry cleaning gas, that is, the plasma of the SF ₆ gas directly acts on the static electricity. Clamp 232 .

Conventionally, since the plasma etching apparatus does not perform dry cleaning, plasma treatment is not performed in the state where the electrostatic jig is not placed on the substrate S, and as the electrostatic jig, thermal spraying using Y ₂ O ₃ or Al ₂ O ₃ is used. It is sufficient to use W or Mo as the film as a dielectric layer and as an adsorption electrode. However, even during dry cleaning, the fluorine-containing gas, ie, SF ₆ gas plasma, acts directly on the electrostatic jig, and the dielectric layer, ie, the spray film of Y ₃ O ₃ or Al ₂ O ₃ has resistance, but it was confirmed that When the sealing material of the spray film is removed by plasma and the plasma and fluorine-containing gas reach the adsorption surface, W or Mo in the adsorption electrode may cause damage and shorten the life of the electrostatic clamp. In order to solve this problem, it is considered that dry cleaning is performed in a state where the dummy substrate, that is, plain glass, is placed on the substrate mounting table 130 in the case of dry cleaning. In the process of moving out plain glass, productivity decreased.

Therefore, in the present embodiment, Al is used as the suction electrode 246 of the electrostatic chuck 232 . Since Al has higher resistance to plasma of SF ₆ gas, which is a fluorine-containing gas, than W or Mo, it is possible to maintain a desired life without placing plain glass during dry cleaning.

Furthermore, the mixed spray film formed by spraying a mixture of aluminum oxide (Al ₂ O ₃ ) and yttrium oxide (Y ₂ O ₃ ) and a silicon compound, and Y ₂ O ₃ relative to the fluorine-containing gas that is SF ₆ Gas plasma resistance is high, so in addition to using Al as the adsorption electrode 246, by using a mixed spray film or Y ₂ O ₃ as the dielectric layer 245, the resistance to SF ₆ gas plasma can be further improved.

In fact, as the material of the adsorption electrode, W, Mo, and Al were compared with respect to the cutting amount of the plasma of the fluorine-containing gas, that is, the SF ₆ gas. As a result, it was confirmed that the cutting amount normalized with the cutting amount of Al as 1 was 10 in W and Mo, and it was confirmed that Al has high resistance to the plasma of SF ₆ , which is a fluorine-containing gas. Furthermore, as the material of the dielectric layer, for Al ₂ O ₃ and Y ₂ O ₃ and the mixed spray film (Al ₂ O ₃ , Y ₂ O ₃ , SiO ₂ ), compared with the fluorine-containing gas, that is, SF ₆ The cutting amount of gas plasma. As a result, it was confirmed that the cutting amount normalized by taking the cutting amount of the mixed spray film as 1 was 3 for Al ₂ O ₃ and 1 for Y ₂ O ₃ , and the mixed spray film and Y ₂ O ₃ were relatively High resistance to plasma containing fluorine gas, ie _SF6 .

In this way, when the cycle of dry cleaning (step 13 ) is repeated after the plasma etching process (step 12 ) is performed a certain number of times, the deposits (adhering to the inside of the chamber 104 of the plasma etching apparatus 90 ) are repeated. material) began to peel off. Therefore, after repeating the cycle for a certain number of times, the chamber 104 is opened for chamber cleaning (step 14). Chamber cleaning is performed by wiping off deposits with alcohol or cleaning with a special chemical solution.

As described above, in the present embodiment, in the etching process of the plasma etching apparatus 90, the gas for etching the substrate S is only a fluorine-containing gas so that the generated reaction product can be dry-cleaned. That is, the SF ₆ gas does not need to use the O ₂ gas that was conventionally used together with the SF ₆ gas. Therefore, during the plasma etching process, MoOx with a low vapor pressure is not generated, and the deposits (attachments) generated in the chamber are only MoFx with a high vapor pressure. Therefore, the deposits (attachments) in the chamber itself are reduced compared to the conventional ones, and the deposits (attachments) in the chamber can be removed by dry cleaning, and the chamber cleaning by opening the chamber can be significantly increased The cycle is the maintenance cycle.

Furthermore, since Al constituting the adsorption electrode 246 of the electrostatic chuck 232 in the plasma etching apparatus 90 has resistance to the plasma of the fluorine-containing gas, that is, the SF ₆ gas at the time of dry cleaning, even if dry cleaning is performed It can also ensure the life of the electrostatic clamp. Furthermore, as the dielectric layer 245 of the electrostatic clamp 232, a mixed spray film or Y ₂ O ₃ is used, thereby further improving the resistance to the plasma of the fluorine-containing gas, that is, the SF ₆ gas.

[Other application]

In addition, the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the idea of the present invention. For example, in the above-mentioned embodiment, although it is suitable for 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 An example will be described, but it is not limited to this. In the plasma etching process of the plasma etching apparatus, the generated reaction product may be used as a process gas capable of being dry cleaned.

In addition, in the above-mentioned embodiment, although the same etching gas as the etching gas in the plasma etching is used as the cleaning gas, the cleaning gas may be different from the etching gas.

In addition, in the above-mentioned embodiment, although the inductively coupled plasma etching apparatus is used as an example of the plasma etching apparatus, it is not limited to this. Other plasma etching devices may also be used.

Claims (19)

A plasma etching method for performing plasma etching on a film containing a specific metal formed on a substrate inside a processing container by a plasma etching apparatus, the plasma etching method is characterized by comprising: in the processing container The process of setting up a substrate mounting table equipped with an electrostatic jig that mounts and adsorbs the above-mentioned substrate, and whose dielectric layer is a mixed spray film formed by spraying a mixture of aluminum oxide, yttrium oxide and silicon compound; in In the plasma etching process of the plasma etching device, a process gas containing chlorine or fluorine and no oxygen is selected so that the generated reaction product can be dry-cleaned; in the above-mentioned plasma etching device, the The above-mentioned film containing the specific metal is subjected to the process of plasma etching treatment using the above-mentioned processing gas; and after the above-mentioned process of carrying out the above-mentioned plasma etching treatment is carried out one or more times for a specific number of times, the above-mentioned process container does not exist in the inside of the above-mentioned process container. A process of dry cleaning the inside of the processing container of the plasma etching apparatus by the plasma of the same gas as the processing gas in the plasma etching process in the state of the substrate. The plasma etching method according to claim 1, wherein the film containing the specific metal is an Al-containing metal film, the processing gas is a chlorine-containing gas, the reaction product is AlClx, and further comprising: After the above-mentioned plasma etching process, the processed substrate is transported to a post-processing device that is installed separately, and the process of post-treatment for corrosion inhibition is performed using O ₂ gas, or O ₂ gas and fluorine-containing gas, and the above-mentioned dry cleaning The process is performed after the process of performing the above-described plasma etching treatment and the process of performing the above-described post-processing are performed one or more times for a specific number of times. The plasma etching method according to claim 2, wherein the chlorine-containing gas in the processing gas is Cl ₂ gas. The plasma etching method according to claim 2 or 3, wherein the Al-containing metal film is a Ti/Al/Ti film for forming the source electrode and the drain electrode of the thin film transistor. The plasma etching method according to claim 1, wherein the film containing the specific metal is a Mo-based material film, the processing gas is a fluorine-containing gas, and the reaction product is MoFx. The plasma etching method according to claim 5, wherein the fluorine-containing gas in the process gas is SF ₆ gas. The plasma etching method according to claim 5 or 6, wherein the Mo-based material film is a Mo film or a MoW film for forming a gate electrode of a thin film transistor or a light-shielding film. A plasma etching apparatus for applying a plasma etching process to a film containing a specific metal formed on a substrate, the plasma etching apparatus is characterized by having: a processing container for accommodating the substrate; and a substrate mounting table for A substrate is placed in the processing container; a gas supply mechanism for supplying a processing gas for performing the plasma etching process and dry cleaning into the processing container; and an exhaust mechanism for exhausting the processing container gas; and a plasma generating mechanism for generating plasma for the plasma etching process and the dry cleaning using the process gas in the process container, wherein the substrate stage has a base material and is provided on the base material and an electrostatic clamp with a dielectric layer composed of a ceramic spray film and an adsorption electrode arranged inside the dielectric layer, and the dielectric layer of the electrostatic clamp is made of molten aluminum, yttrium oxide and silicon. A mixed spray film formed by a mixture of compounds, the above-mentioned film containing a specific metal is subjected to the above-mentioned plasma etching treatment by plasma, and the plasma is selected as the above-mentioned processing gas to cause the generated reaction. The product is generated as a dry-cleanable gas containing chlorine or fluorine and not containing oxygen, and in the processing container after the plasma etching treatment is performed once or twice or more for a specific number of times, inside the processing container In a state in which the above-mentioned substrate is not present, the plasma generated by using the same gas as the processing gas in the above-mentioned plasma etching process is dry cleaned. The plasma etching apparatus according to claim 8, wherein silicon oxide or silicon nitride is used as the silicon compound for the hybrid spray film of the dielectric layer constituting the electrostatic chuck. The plasma etching apparatus according to claim 8 or 9, wherein the processing gas system contains a chlorine gas, and the adsorption electrode of the electrostatic chuck is made of tungsten or molybdenum. The plasma etching apparatus according to claim 8 or 9, wherein the processing gas is Cl ₂ gas. The plasma etching apparatus according to claim 8 or 9, wherein the processing gas is a fluorine-containing gas, and the adsorption electrode is made of aluminum. The plasma etching apparatus according to claim 8 or 9, wherein the processing gas is SF ₆ gas. A substrate stage for performing a plasma etching process on a film containing a specific metal formed on a substrate in a process container by plasma, the plasma being selected as a process gas so that the generated The reaction product becomes a dry-cleaning gas containing chlorine or fluorine and not containing oxygen, and is generated by using the same gas as the processing gas in the above-mentioned plasma etching Plasma, in the above-mentioned processing container after the above-mentioned plasma etching treatment is performed once or twice or more for a specified number of times, in a state where the substrate is not present in the inside of the above-mentioned processing container, in a plasma etching apparatus for dry cleaning, A substrate is placed in the above-mentioned processing container, and the substrate placing table is characterized by having: a base material; The adsorption electrode inside the above-mentioned dielectric layer, the above-mentioned dielectric layer of the above-mentioned electrostatic clamp is a mixed spray film formed by spraying a mixture of aluminum oxide, yttrium oxide and silicon compound. The substrate stage according to claim 14, wherein the dielectric layer of the electrostatic jig uses silicon oxide or silicon nitride as a silicon compound. The substrate stage according to claim 14 or 15, wherein the processing gas is a chlorine-containing gas, and the adsorption electrode of the electrostatic jig is made of tungsten or molybdenum. The substrate stage according to claim 14 or 15, wherein the processing gas is Cl ₂ gas. The substrate stage according to claim 14 or 15, wherein the processing gas is a fluorine-containing gas, The above-mentioned adsorption electrode is made of aluminum. The substrate stage according to claim 14 or 15, wherein the processing gas is SF ₆ gas.

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