TW202209487A - Substrate detaching method and plasma processing device characterized by suppressing the decrease of the electrostatic adhesion force of a substrate - Google Patents

Abstract

The object of the present invention is to suppress the decrease of the electrostatic adhesion force of a substrate. A substrate detaching method is a method that detaches a substrate adhered by the static electricity from an electrostatic fixture by applying a DC voltage on the adhesion electrode built in the electrostatic fixture inside a processing container, and has the following processes: a process that provides the electricity-removing gas to the interior of the processing container to generate the plasma of the electricity-removing gas, at the state of the substrate processed by a plasma process being adhered on the electrostatic fixture by electrostatic adhesion; a process that maintains the plasma of the electricity-removing gas while using a lifting pin to allow the substrate to be lifted and detached from the electrostatic fixture; and a process that applies a negative DC voltage on the adhesion electrode.

Description

Substrate detachment method and plasma processing apparatus

The present invention relates to a substrate detachment method and a plasma processing apparatus.

After a positive DC voltage is applied to the electrodes of the electrostatic jig to attract the substrate to the electrostatic jig and the substrate is processed, when the substrate is detached from the electrostatic jig, a static elimination treatment is performed. The pins are lifted to raise the substrate, thereby removing residual charge. For example, Patent Document 1 proposes a technique for performing a static elimination treatment, in which electric charges on the surface of the substrate are removed by utilizing the electrical conductivity of the plasma when the substrate is detached from the electrostatic jig. In Patent Document 1, the substrate is lifted from the electrostatic jig by raising the lift pins in the presence of plasma.

For example, Patent Document 2 proposes a technique of supplying a heat transfer gas having a second pressure to the inner surface of the substrate while plasma-eliminating the substrate by the plasma of the processing gas having the first pressure. In Patent Document 2, in order to electrostatically attract the substrate during the plasma treatment, a DC voltage of opposite polarity to the DC voltage applied to the electrodes of the electrostatic jig is applied to the electrodes.

[Prior Art Literature]

[Patent Literature]

Patent Document 1: Japanese Patent Laid-Open No. 2002-134489

Patent Document 2: Japanese Patent Laid-Open No. 2015-95396

The present invention provides a substrate detachment method and a plasma processing apparatus capable of suppressing a decrease in the electrostatic attraction force of the substrate.

According to one aspect of the present invention, there is provided a method for removing a substrate, by applying a DC voltage to an adsorption electrode embedded in an electrostatic clamp inside a processing container, so that the electrostatically adsorbed substrate is released from the electrostatically adsorbed substrate. The method of removing the electrostatic jig has the following steps: in a state in which the substrate to which the plasma treatment has been applied is electrostatically attracted to the electrostatic jig, a static-eliminating gas is supplied to the inside of the processing container to generate the static-eliminating gas. The process of plasma; the process of raising the substrate by lift pins while maintaining the plasma of the static-removing gas to be separated from the electrostatic jig; and the process of applying a negative DC voltage to the adsorption electrode.

According to one aspect, the decrease in the electrostatic attraction force of the substrate can be suppressed.

10: Handling the container

12: Upper chamber

12a: Top plate

13: Lower chamber

13a: Sidewall

13d: Bottom plate

13f: exhaust port

30: Sprinkler

50: Gas exhaust part

60: Substrate mounting table

64: Ceramic layer

65: Adsorption electrode

66: Electrostatic fixture

74: Power supply line

75: DC power supply

76, 77: switch

78: Lift Pin

90: Control Department

100: Plasma processing device

G: substrate

P1, P2: Plasma

R: sediment

S: Processing room

FIG. 1 is a schematic cross-sectional view showing a plasma processing apparatus related to one embodiment.

FIG. 2 is a diagram showing an example of a conventional substrate release method.

FIG. 3 is a diagram for explaining peeling electrification.

FIG. 4 is a diagram for explaining peeling electrification.

FIG. 5 is a diagram for explaining a method of releasing a substrate according to an embodiment.

FIG. 6 is a flow chart showing a method for releasing a substrate according to an embodiment.

Hereinafter, the mode for implementing the present invention will be described with reference to the drawings. In each of the drawings, the same components are given the same reference numerals, and overlapping descriptions may be omitted.

[Plasma processing device]

First, referring to FIG. 1 , an example of a plasma processing apparatus 100 related to an embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing an example of a plasma processing apparatus 100 related to an implementation.

The plasma processing apparatus 100 is an inductive coupled plasma (ICP) processing apparatus that performs various substrate processing methods on a rectangular substrate for FPD (hereinafter referred to as a “substrate”) G in plan view. As the material of the substrate, glass is mainly used, and a transparent synthetic resin or the like may be used depending on the application. Here, the substrate treatment includes etching treatment, film formation treatment using a CVD (Chemical Vapor Deposition) method, and the like. The FPD is exemplified by a liquid crystal display (Liquid Crystal Display: LCD). It can also be an electroluminescence (Electro Luminescence: EL), a plasma display panel (Plasma Display Panel; PDP), and the like. In addition to the existence of the substrate G on the surface of the substrate G In addition to the type of the patterned circuit, a support substrate is also included. In addition, the plane size of the substrate for FPD increases in size with the passage of generations. The plane size of the substrate G to be processed by the plasma processing apparatus 100 includes, for example, a size of about 1500 mm×1800 mm in the sixth generation to a size of about 3000 mm×3400 mm in the 10.5th generation. Moreover, the thickness of the board|substrate G is about 0.2 mm to several mm.

The plasma processing apparatus 100 includes a box-shaped processing container 10 having a rectangular parallelepiped shape, a substrate mounting table 60 arranged in the processing container 10 and having the substrate G mounted thereon and having a rectangular shape in plan view, and a control unit 90 . The processing container 10 may also be in the shape of a cylindrical box shape or an elliptical cylindrical box shape. In this type, the substrate placing table 60 is also circular or elliptical, and the substrate placed on the substrate placing table 60 G is also a circle and so on.

The processing chamber 10 is divided into two spaces up and down by the dielectric plate 11, the antenna chamber which is the upper space is formed by the upper chamber 12, and the processing chamber S which is the lower space is formed by the lower chamber. A chamber 13 is formed. The processing container 10 is formed of metal such as aluminum, and the dielectric plate 11 is formed of ceramics such as alumina (Al ₂ O ₃ ) or quartz.

In the processing container 10, a ring-shaped rectangular support frame 14 is disposed so as to protrude inside the processing container 10 at a position that becomes the boundary between the lower chamber 13 and the upper chamber 12. Dielectric plate 11 . The processing container 10 is grounded by the ground wire 13e.

The side wall 13a of the lower chamber 13 is provided with an unloading inlet 13b for carrying the substrate G in and out of the lower chamber 13, and the loading and unloading entrance 13b is freely openable and closable by the gate valve 20. The lower chamber 13 is adjacent to a transfer chamber including a transfer mechanism (not shown), and the gate valve 20 is opened and closed, and the substrate G is carried in and out through the transfer port 13b by the transfer mechanism.

In addition, the bottom plate 13d of the lower chamber 13 is provided with a plurality of exhaust ports 13f. The gas exhaust pipe 51 is connected to the exhaust port 13 f , and the gas exhaust pipe 51 is connected to the exhaust device 53 through the pressure control valve 52 . The gas exhaust part 50 is formed by the gas exhaust pipe 51 , the pressure control valve 52 and the exhaust device 53 . The exhaust device 53 has a vacuum pump such as a turbo molecular pump, and can freely evacuate the lower chamber 13 to a specific vacuum degree during the process.

The lower surface of the dielectric plate 11 is provided with a supporting beam for supporting the dielectric plate 11 , and the supporting beam also serves as the shower head 30 . The shower head 30 is formed of metal such as aluminum, and can be surface-treated by anodizing. A gas flow channel 31 extending in the horizontal direction is formed in the shower head 30 . gas flow channel 31 is communicated with a gas ejection hole 32 extending below and facing the processing chamber S located below the shower head 30 .

The upper surface of the dielectric plate 11 is connected with a gas introduction pipe 45 which communicates with the gas channel 31 . The gas introduction pipe 45 airtightly penetrates the supply port 12b opened in the top plate 12a of the upper chamber 12 and is connected to the processing gas supply source 44 through the gas supply pipe 41 airtightly combined with the gas introduction pipe 45 . An on-off valve 42 and a flow controller 43 such as a mass flow controller are interposed at a midway position of the gas supply pipe 41 . The processing gas supply part 40 is formed by the gas introduction pipe 45 , the gas supply pipe 41 , the on-off valve 42 , the flow controller 43 , and the processing gas supply source 44 . The process gas system supplied from the process gas supply part 40 is supplied to the shower head 30 through the gas supply pipe 41 and the gas introduction pipe 45 , and is ejected to the processing chamber S through the gas flow channel 31 and the gas ejection holes 32 .

A high-frequency antenna 15 is arranged in the cavity 12 above the antenna chamber. The high-frequency antenna 15 is formed by winding an antenna 15a made of a conductive metal such as copper in a ring shape or a spiral shape. For example, the loop-shaped antenna 15a may be arranged in multiples.

The terminal of the antenna 15a is connected with a power supply component 16 extending above the upper chamber 12, and the upper end of the power supply component 16 is connected with a power supply line 17, and the power supply line 17 is connected to the high-voltage terminal through a matcher 18 for impedance matching. frequency power supply 19. An induced electric field is formed in the lower chamber 13 by applying, for example, high-frequency electric power of 10 MHz to 15 MHz to the high-frequency antenna 15 from the high-frequency power supply 19 . By the induced electric field, the process gas supplied from the shower head 30 to the process chamber S is plasmaized to generate an inductively coupled plasma, which supplies the substrate G with ions or neutral radicals in the plasma. Wait. The high-frequency power source 19 is a source for generating plasma, and the high-frequency power source 73 connected to the substrate stage 60 is a bias source that attracts the generated ions and imparts kinetic energy. In this way, the source of ions uses inductive coupling to generate plasma, and the bias source for other power sources is connected to the substrate stage 60 to control the ion energy. In this way, the generation of plasma and the control of ion energy can be independently performed, thereby increasing the degree of freedom of the process. The frequency of the high-frequency electric power output from the high-frequency power supply 19 is preferably set within a range of 0.1 to 500 MHz.

The substrate stage 60 includes a base material 63 and an electrostatic chuck 66 formed on the upper surface 63 a of the base material 63 . The substrate 63 has a rectangular shape when viewed from above, and has the same plane size as the substrate G placed on the substrate stage 60. The length of the long side can be set to about 1800mm to 3400mm, and the length of the short side can be set to About 1500mm to 3000mm or so in size. With respect to this plane size, The thickness of the base material 63 may be, for example, about 50 mm to 100 mm. The base material 63 is formed of stainless steel, aluminum, aluminum alloy, or the like. The substrate 63 is provided with a temperature-controlled media flow channel 62a that snakes like covering the entire area of the rectangular plane. In addition, the temperature control medium flow channel 62a can also be disposed in the electrostatic clamp 66, for example. In addition, the base material 63 may be formed by a laminate of two components instead of a single body composed of one component as shown in the example.

The two ends of the temperature control medium flow channel 62a are connected with a sending pipe 62b for supplying the temperature control medium relative to the temperature control medium flow channel 62a, and the temperature control medium after being heated by circulating in the temperature control medium flow channel 62a. The discharge return piping 62c. The delivery pipe 62b and the return pipe 62c communicate with the delivery flow passage 82 and the return flow passage 83, respectively, and the delivery flow passage 82 and the return flow passage 83 communicate with the cooler 81 . The cooler 81 has a main body for controlling the temperature of the temperature control medium or the ejection flow rate, and a pump (not shown) for pressurizing the temperature control medium. In addition, a refrigerant is used as a temperature control medium, and GALDEN (registered trademark) or FLUORINERT (registered trademark) or the like is used as the refrigerant. Although the temperature control type of the illustrated example is a type in which the temperature control medium is circulated in the substrate 63, the substrate 63 may have a built-in heater, etc., and the temperature is controlled by the heater. It can also be a type of temperature control by both a temperature control medium and a heater. In addition, instead of the heater, temperature control accompanying heating may be performed by circulating a high temperature temperature control medium. In addition, the heater, which is a resistive body, is formed of tungsten or molybdenum, or a compound of any of these metals with alumina, titanium, or the like. In addition, although the illustrated example is based on forming the temperature-controlled medium flow channel 62a on the substrate 63, for example, the electrostatic clamp 66 may also have a temperature-controlled medium flow channel.

On the bottom plate 13d of the lower chamber 13, a box-shaped pedestal 68 formed of an insulating material and having a stepped portion inside is fixed, and the substrate mounting table 60 is placed on the stepped portion of the pedestal 68. An electrostatic chuck 66 on which the substrate G is directly placed is formed on the upper surface of the base material 63 . The electrostatic clamp 66 has a ceramic layer 64 formed by spraying ceramics such as alumina with a flame and is a dielectric coating film, and an adsorption electrode 65 embedded in the ceramic layer 64 and a conductive layer having an electrostatic adsorption function. The suction electrode 65 is connected to the DC power supply 75 through the power supply line 74 and the switch 76 . When the switch 76 is turned on by the control unit 90 , a Coulomb force is generated by applying a DC voltage from the DC power source 75 to the adsorption electrode 65 . Due to this Coulomb force, the substrate G is electrostatically attracted to the electrostatic chuck 66 , and is held in a state of being placed on the upper surface of the base material 63 . In addition, when the switch 76 is turned off and the switch 77 interposed by the ground line branched from the power supply line 74 is turned on, the electric charge accumulated in the adsorption electrode 65 flows to the ground. In this way, the lower electrode on which the substrate G is placed is formed on the substrate stage 60 .

The substrate 63 is equipped with a temperature sensor such as a thermocouple, and the sensing information obtained by the temperature sensor is transmitted to the control unit 90 at any time. The control unit 90 implements temperature control of the substrate 63 and the substrate G according to the transmitted temperature sensing information. More specifically, the temperature or flow rate of the temperature control medium supplied from the cooler 81 to the delivery channel 82 is adjusted by the control unit 90 . Then, the temperature control of the substrate stage 60 is performed by circulating the temperature control medium whose temperature or flow rate has been adjusted in the temperature control medium flow channel 62a. In addition, a temperature sensor such as a thermocouple may be arranged in the electrostatic jig 66 , for example.

A rectangular frame-shaped focus ring 69 is placed on the upper surface of the pedestal 68 which is the outer periphery of the electrostatic chuck 66 , and the upper surface of the focus ring 69 is set to be lower than the upper surface of the electrostatic chuck 66 . The focus ring 69 is formed of ceramics such as alumina, quartz, or the like.

A power supply assembly 70 is connected to the lower surface of the base material 63 . A power supply line 71 is connected to the lower end of the power supply component 70 , and the power supply line 71 is connected to a high frequency power supply 73 which is a bias source through a matcher 72 for impedance matching. The ions generated by the high-frequency power source 19 , which is a source for plasma generation, can be attracted to the substrate G by applying, for example, a high-frequency electric power of 2 MHz to 6 MHz to the substrate stage 60 from the high-frequency power source 73 . Therefore, in the plasma etching process, the etching rate and the etching selectivity ratio can be improved at the same time.

The inside of the substrate stage 60 is provided with a plurality of (eg, 12) lift pins 78 for moving the substrate G up and down in order to transfer the substrate G to and from an external transfer arm (not shown). In FIG. 1, two lift pins 78 are shown in a simplified diagram. The plurality of lift pins 78 penetrate through the substrate placing table 60 and move up and down by the power of the motor transmitted through the connecting element. The through hole of the lift pin 78 penetrating toward the outside of the processing vessel is provided with a bottom telescopic tube (not shown) to maintain airtightness between the vacuum side and the atmosphere side in the processing vessel.

The control unit 90 controls the operations of the components of the plasma processing apparatus 100 , for example, the cooler 81 , the high-frequency power sources 19 and 73 , the DC power source 75 , the processing gas supply unit 40 , and the gas exhaust unit 50 . The control unit 90 includes a CPU (Central Processing Unit), and memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory). The CPU performs specific processing according to the recipe (process recipe) stored in the memory area of the memory. The recipe is set with control information of the plasma processing apparatus 100 relative to the process conditions. The control information includes, for example, gas flow or pressure within the processing vessel 10, temperature within the processing vessel 10 or temperature of the substrate 63, process time, and the like.

The recipe and the program applied by the control unit 90 can be stored in, for example, a hard disk, an optical disk, a magneto-optical disk, or the like. In addition, the recipe or the like may be installed in the control unit 90 and read in a state of being accommodated in a portable computer-readable storage medium such as CD-ROM, DVD, and memory card. In addition to this, the control unit 90 includes an input device such as a keyboard or a mouse that can perform input operations of commands, a display device such as a display that visually displays the operating status of the plasma processing device 100 , and an output such as a printer. The user interface of the device.

[Conventional substrate detachment method and stripping charging]

Next, with reference to FIGS. 2 to 4 , the conventional method of separating the substrate and the stripping charging will be described. FIG. 2 is a diagram showing an example of a conventional substrate release method. 3 and 4 are diagrams for explaining peeling charging.

In the conventional substrate separation method, firstly, as shown in FIG. 2( a ), the suction electrode 65 is connected to the DC power supply 75 through the power supply line 74 . When the switch 76 is controlled to be on by the control unit 90 , a DC voltage is applied from the DC power supply 75 to the adsorption electrode 65 . Thereby, a Coulomb force is generated, and the substrate G is electrostatically attracted and held on the upper surface of the electrostatic chuck 66 . In the example of FIG. 2( a ), when the substrate G is etched by the plasma P1 , a positive DC voltage is applied to the adsorption electrode 65 from the DC power supply 75 , and a positive charge is generated on the adsorption electrode 65 , and the substrate On G, a negative charge is generated. However, it is not limited to this, and when a negative DC voltage is applied to the suction electrode 65 from the DC power supply 75 , a negative charge is generated on the suction electrode 65 and a positive charge is generated on the substrate G.

When the substrate G is etched, a reaction product is generated. The reaction product enters between the substrate G and the electrostatic jig 66 and adheres to the substrate placement surface of the electrostatic jig 66 . When the number of times of processing the substrate G is repeated, the reaction product is deposited on the substrate placement surface. Hereinafter, the deposited reaction product is referred to as deposit R.

FIG. 3 shows a state in which the deposit R is deposited on the substrate placement surface. The left diagram of FIG. 3 shows a state in which a DC voltage is applied from the DC power supply 75 to the attracting electrode 65 to electrostatically attract the substrate G to the upper surface of the electrostatic jig 66 . In this state, the substrate G is etched with plasma.

The right diagram in FIG. 3 shows a state in which the application of the DC voltage from the DC power supply 75 to the suction electrode 65 is stopped, and the lift pins 78 are raised to release the substrate G from the electrostatic chuck 66 after the etching is completed. At this time, the electric conduction using the plasma P is performed by supplying the antistatic gas to generate the plasma P of the antistatic gas. De-staticization (hereinafter also referred to as "plasma de-staticization") to electrically remove the charge on the surface of the substrate G. In the plasma elimination, the lift pins 78 are raised in the presence of plasma to lift the substrate G from the electrostatic jig 66 .

The etching gas system used for the etching of the substrate G contains fluorine. In addition, in the etching of the substrate G, the insulating film of the lower layer of the mask is etched through the mask of the organic material formed on the substrate G. As the insulating film, there are a SiO ₂ film, a SiN film, and the like. During etching, part of the mask is removed. As a result, the deposit R deposited on the substrate placement surface of the electrostatic chuck 66 contains fluorine in the etching gas and carbon in the mask.

Figure 4 shows the triboelectric train between substances. The substances described under the arrows indicate that the farther to the left of the arrow, the more likely it is to be positively (+) charged, and the farther to the right, the more likely to be negatively (-) charged. For example, in the combination of "glass" and "polytetrafluoroethylene (tetrafluoroethylene (CF ₂ =CF ₂ ))", "glass" tends to have a positive (+) charge, while "polytetrafluoroethylene" tends to Has a negative (-) charge. Also, when any substance is located close to the same polarity side (such as the positive (+) on the left) shown in the triboelectricity sequence, the substance on the left will be positively (+) charged, And the matter on the right side will be negatively (-) charged. For example, in the combination of "glass" and "fur", "glass" tends to be positively (+) charged, while "fur" tends to be negatively (-) charged. The peeling electrification is generated by the electrification of each substance when the two substances in contact are separated, and the polarity of the electrification generated at this time is based on the relationship between the substance and the polarity shown in the above triboelectric electrification column.

As can be seen from the above, as shown in FIG. 3 , when the DC voltage applied from the DC power supply 75 to the adsorption electrode 65 is stopped, the negative charges on the substrate G are eliminated while flowing to the ground through the plasma, and the negative charges on the substrate G are eliminated. When the lift pins 78 are raised, peeling electrification occurs between the substrate G and the deposit R. When the substrate shown in FIG. 3 is detached, since the “glass” of the substrate G and the “deposit R” containing C and F on the substrate mounting surface are separated and charged, as shown in FIG. 4 , the substrate G becomes will be positively charged, while the deposit R is negatively charged. Although the "deposit R" here is not necessarily polytetrafluoroethylene, it is presumed that it should have the same electrical properties because of the composition containing C and F.

The reasons for the generation of the residual charge remaining on the electrostatic chuck 66 and the negative charge on the deposit R due to the stripping electrification are different. The residual charge remaining in the electrostatic clamp 66 is generated by the DC voltage applied to the adsorption electrode 65 from the DC power supply 75 , and the positive and negative of the residual charge changes due to the positive and negative DC voltage applied to the adsorption electrode 65 . In the case of plasma removal, for example, the DC voltage applied from the DC power source 75 to the adsorption electrode 65 during the plasma treatment is a DC voltage with opposite polarity but the same magnitude. Pressure is applied to the suction electrode 65 to remove the residual charges on the substrate G while passing through the plasma and flowing to the ground.

On the other hand, the peeling charge generated when the substrate is peeled off is a charge that depends on the electrical properties of the substance and is based on the combination of the substances after peeling. Therefore, regardless of the positive or negative of the DC voltage applied from the DC power source 75 to the attracting electrode 65, as shown in the example of triboelectric charging in FIG. Zone "negative" electricity.

Therefore, in the substrate detachment method according to this embodiment, in order to remove the negative charge on the deposit R when the substrate G is detached by the lift pins 78 or after the detachment, the suction electrode 65 is applied from the DC power supply 75 to the suction electrode 65 . Negative DC voltage. Thereby, positive charges, which are neutralized with the negative charges on the deposit R, are generated on the surface of the electrostatic chuck 66 . As a result, the negative charge on the deposit R can be neutralized and removed. In this way, it is possible to prevent the adsorption force of the substrate G from being lowered due to the negative charge on the deposit R during the adsorption of the next substrate G, thereby suppressing the peeling of the substrate G. FIG.

That is, in the conventional substrate separation method shown in FIG. 2, after the DC voltage applied to the suction electrode 65 from the DC power supply 7a (shown in FIG. 2(b)) is stopped, the lift pins 78 are raised while the lift pins 78 are raised. Plasma elimination (shown in FIG. 2( c )) is performed by the plasma of the neutralizing gas (hereinafter also referred to as “plasma P2 for eliminating electricity”). Here, residual charges on the substrate G are removed. However, negative charges on the deposit R remain due to peeling electrification generated when the substrate G is peeled off by the lift pins 78 . If the next substrate G is placed on the substrate placement surface with the negative charge remaining on the deposit R, as shown in FIG. A part of the positive charge on the suction electrode 65 generated by the positive DC voltage applied by the DC power source 75 to the suction electrode 65 and the negative charge on the deposit R will attract each other. As a result, the negative charges on the substrate G that are attracted to the positive charges on the adsorption electrode 65 will be insufficient, resulting in a decrease in the adsorption force. As a result, the substrate G is easily peeled off from the electrostatic jig 66 . In addition, in order to improve the temperature control efficiency of the substrate G, although the heat transfer gas is filled between the substrate G and the electrostatic clamp 66, the adsorption force of the adsorption electrode 65 is reduced, and the heat transfer gas above the allowable range may be generated from the substrate. The problem of leakage between G and electrostatic clamp 66 .

On the other hand, in a state where the substrate G is not placed in the plasma processing apparatus 100 , a fluorine-based gas is supplied to generate a plasma of the fluorine-based gas to remove the deposit on the electrostatic jig 66 by cleaning. R. However, in this case, the substrate mounting surface of the substrate mounting table 60 is also degraded by being exposed to the plasma at the same time, which leads to a shortening of the life of the substrate mounting table 60 .

Therefore, in the substrate separation method according to one of the embodiments described below, as shown in FIG. 5 , (a) etching, (b) DC voltage shutdown, (c) static elimination due to lift pins rising, and (d) etching of the next substrate G. The processing of Figs. 5(a) and (b) is the same as the conventional substrate release method shown in Figs. 2(a) and (b). After the DC voltage of FIG. 5( b ) is turned off, as shown in FIG. 5( c ), a negative DC voltage is applied to the adsorption electrode 65 from the DC power supply 75 in the plasma elimination. Thereby, the stripping-charged negative charges on the deposit R can be removed. As a result, as shown in FIG. 5( d ), in the processing of the next substrate G, the adsorption force when the substrate G is adsorbed to the electrostatic chuck 66 can be prevented from being lowered, and the peeling of the substrate G can be suppressed.

[Substrate detachment method]

The substrate detachment method MT related to this embodiment will be described with reference to FIG. 6 . FIG. 6 is a flow chart showing a method MT of removing a substrate according to an implementation form. The present method MT is implemented by the plasma processing apparatus 100 under the control of the control unit 90 .

After the present method MT is started, the substrate G on which the organic material mask and the underlying insulating film are laminated is carried into the lower chamber 13 and placed on the substrate placement surface of the electrostatic jig 66 (step S1 ).

Next, a positive DC voltage is applied to the suction electrode 65 from the DC power supply 75 to suction the substrate G to the electrostatic chuck 66 (step S2). Next, a fluorine-containing gas is supplied from the processing gas supply source 44 and a high-frequency electric power is applied from the high-frequency power source 19 to generate a fluorine-containing gas plasma (step S3), and the fluorine-containing gas plasma is etched on the substrate G. insulating film (step S4). At this point in time, as shown in FIG. 5( a ), the switch 76 is turned on, and a positive DC voltage is applied from the DC power supply 75 to the suction electrode 65 . At this time, the switch 77 is controlled to be off. The insulating film is etched through the mask of the organic material on the substrate G by the plasma P1 containing the fluorine gas.

Next, it is determined whether or not the etching of the insulating film is terminated (step S5). For example, whether or not to end the etching can be determined by a method such as EPD (End Point Detection). If it is determined that the etching of the insulating film is not completed, the process returns to step S4 and the etching of the substrate G is continued. On the other hand, when it is determined that the etching of the insulating film has ended, the supply of the fluorine-containing gas and the application of the high-frequency electric power are stopped, and the switch 76 is turned off to stop the application of the positive DC voltage to the adsorption electrode 65 . Then, the etching is ended (step S6). At this point in time, as shown in FIG. 5( b ), the switch 76 is controlled to be OFF to stop the application of the positive DC voltage to the suction electrode 65 . When the switch 77 is controlled to be on, the positive charge on the adsorption electrode 65 will flow to the ground.

Next, the gas for static elimination is supplied from the process gas supply source 44, and the high frequency electric power is applied from the high frequency power supply 19, and the plasma for static elimination is produced|generated (step S7). An example of the gas for removing electricity includes O ₂ gas, argon gas, and helium gas. In addition, the high-frequency electric power in step 7 is the high-frequency electric power applied from the high-frequency power supply 19 , but the high-frequency electric power is not applied from the high-frequency power supply 73 .

Next, the lift pins 78 are raised to release the substrate G from the electrostatic chuck 66 (step S8). At this point in time, as shown in FIG. 5( c ), while performing plasma neutralization to remove the residual charge on the surface of the substrate G by utilizing the conductivity of the plasma P2 for neutralization, the lift pins 78 are used to remove electricity. The substrate G is released from the substrate placement surface of the electrostatic jig 66 . Next, a negative DC voltage is applied to the adsorption electrode 65 from the DC power supply 75 to remove the negative charge on the deposit R (step S9). As a result, since the negative charge on the deposit R is removed, as shown in FIG. 5( d ), when the next substrate G is carried in and electrostatically attracted, the negative charge on the deposit R can be prevented from being caused by the negative charge on the deposit R. As a result, the adsorption force is lowered, and it is possible to suppress the substrate G from being easily peeled off from the electrostatic jig 66 . Thereby, the leakage amount of the heat transfer gas that leaks from between the substrate G and the electrostatic jig 66 can be prevented from exceeding the allowable range.

Next, the supply of the neutralizing gas is stopped, and the application of the high-frequency electric power is stopped to stop the generation of the neutralizing plasma (step S10 ). Next, the application of the negative DC voltage from the DC power supply 75 to the attracting electrode 65 is stopped (step S11). With this, the method MT ends.

In addition, in the above description, although the process of step S9 is performed after the process of step S8, the process of step S8 and the process of step S9 may be performed in parallel. For example, the process of step S9 may be performed after starting the process of step S8 and peeling off the board|substrate G from the board|substrate mounting surface. The process of step S8 and the process of step S9 may be started at the same time. That is, the process of step S9 may be started simultaneously with the process of step S8, or after the start of the process of step S8.

As described above, according to the substrate detachment method of the present embodiment, the decrease in the electrostatic attraction force of the substrate can be avoided. Thereby, peeling of a board|substrate can be suppressed. In addition, the leakage amount of the heat transfer gas supplied between the substrate and the electrostatic jig can be within an allowable range.

In addition, the step of releasing the substrate G from the electrostatic jig 66 may be controlled so that the control unit 90 raises the lift pins 78 to a height of 30 mm or more from the substrate placement surface of the electrostatic jig 66 . Thereby, the plasma for static elimination becomes easy to wind around the inner surface of the board|substrate G. In this way, the charge on the inner surface of the substrate G and the negative charge on the deposit R can be removed more easily.

The substrate separation method and the plasma processing apparatus related to one embodiment disclosed in this specification should be considered as all points only for illustration and not for limiting the scope of the present invention. The above-described embodiments can be modified and improved in various forms within the scope of not departing from the scope of the appended claims and the gist thereof. The matters described in the above-mentioned plural embodiments may be added with other structures within the scope of inconsistency, and may also be combined within the scope of inconsistency.

The plasma treatment device of the present invention can also be applied to Atomic Layer Deposition (ALD) device, Capacitively Coupled Plasma (CCP), Inductively Coupled Plasma (ICP), Radial Line Slot Antenna (RLSA), Electron Cyclotron Resonance Plasma (ECR), Helicon Wave Plasma (HWP) any type of plasma processing device.

In addition, the plasma processing apparatus is not limited to etching, and can be applied as long as it is an apparatus for performing specific plasma processing such as film formation processing on a substrate using plasma.

64: Ceramic layer

65: Adsorption electrode

66: Electrostatic fixture

74: Power supply line

75: DC power supply

76, 77: switch

G: substrate

P1, P2: Plasma

R: sediment

Claims (7)

A substrate detachment method is to apply a DC voltage to an adsorption electrode embedded in an electrostatic jig inside a processing container, so that the electrostatically adsorbed substrate is detached from the electrostatic jig. The method includes the following steps: The process of generating the plasma of the antistatic gas by supplying the antistatic gas to the inside of the processing container in a state in which the substrate to which the plasma treatment has been applied is electrostatically attracted to the electrostatic jig; while maintaining the plasma of the static-removing gas, the substrate is lifted by a lift pin to be separated from the electrostatic jig; and A process of applying a negative DC voltage to the adsorption electrode. The substrate separation method of claim 1, which has the following step before the step of generating the plasma of the antistatic gas, which is to stop the DC voltage applied to the adsorption electrode during the plasma treatment. The method for releasing the substrate as claimed in claim 1 or 2 of the claimed scope, wherein the plasma treatment is to supply a fluorine-containing gas, and the plasma of the fluorine-containing gas is used to etch the substrate through a mask formed of an organic material. the treatment of the existing film. The substrate separation method according to any one of claims 1 to 3 of the claimed scope includes a step of stopping the plasma of the antistatic gas during the step of applying a negative DC voltage to the adsorption electrode. The substrate detachment method according to any one of claims 1 to 4, wherein the step of applying a negative DC voltage to the suction electrode is performed during the step of detaching the substrate from the electrostatic jig. The method for releasing the substrate according to any one of claims 1 to 5 of the claimed scope, wherein the step of releasing the substrate from the electrostatic jig is to raise the lift pins to a height of 30 mm or more from the substrate placement surface of the electrostatic jig . A plasma processing apparatus comprising: a processing container; an electrostatic jig disposed inside the processing container; and a control unit that controls by applying a DC voltage to a suction electrode embedded in the electrostatic jig to make Electrostatic adsorption of substrate; The control unit will control: The process of generating the plasma of the antistatic gas by supplying the antistatic gas to the inside of the processing container in a state in which the substrate to which the plasma treatment has been applied is electrostatically attracted to the electrostatic jig; while maintaining the plasma of the static-removing gas, the substrate is lifted by a lift pin to be separated from the electrostatic jig; and A process of applying a negative DC voltage to the adsorption electrode.

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