TWI606547B - Plasma processing chamber and its de-chucking device and method - Google Patents

Description

Plasma processing chamber and its removal device and method

The present invention relates to the field of semiconductor manufacturing, and more particularly to a plasma processing chamber and a device and method for removing the same.

Micromachining of semiconductor substrates or substrates is a well-known technique that can be used to fabricate, for example, semiconductors, flat panel displays, light emitting diodes (LEDs), solar cells, and the like. The different steps of microfabrication fabrication may include a plasma assisted process (e.g., plasma enhanced chemical vapor deposition, reactive ion etching, etc.) that is performed inside the reaction chamber where process gases are input. An RF source is coupled to the interior of the reaction chamber by an inductor and/or a capacitor to excite the process gas to form and maintain the plasma. Inside the reaction chamber, the exposed substrate is supported by the chuck and fixed in a fixed position by some kind of clamping force.

In order to meet the process requirements, not only the process control process needs to be strictly controlled, but also the loading and removal of the semiconductor substrate. Loading and unclamping of semiconductor substrates is a critical step in semiconductor substrate processing.

Conventional techniques have only used a lifting ejector to remove the substrate from the electrostatic chuck, which may cause irreversible damage to the substrate. It is well known that since the substrate is processed by plasma, there is also a charge on the substrate, particularly on the bottom surface of the substrate, after the substrate has been processed. The prior art has disclosed a procedure for discharging the charge on the substrate, and in an ideal state, the substrate can be unclamped after the discharge process is performed on the substrate. However, as the mechanism ages, residual charge may still be present on the substrate after the discharge process of the substrate.

It will be understood by those skilled in the art that the substrate bottom typically still has residual charge which causes the substrate to draw a substrate onto the electrostatic chuck due to static suction between the electrostatic chuck and the electrostatic chuck. Due to the limited number of lifting thimbles, it does not evenly act on the entire back of the substrate. Therefore, in some areas of the substrate where there is no lift ejector contact, the downward suction is greater than the upward thrust of the lift ejector pin, and in other parts of the substrate due to the direct contact of the lift ejector pin, the lift of the lift ejector pin is greater than With a downward suction, the cymbal will be damaged due to local distortion. Moreover, since the thrust of the lift ejector pin is a transient force, its sudden action on the substrate may cause the substrate to suddenly eject away from the electrostatic chuck, which may cause the substrate to be damaged by the elastic force. Further, due to the limited space of the plasma processing system, the above-mentioned de-clamping mechanism only takes a limited number of lifting thimbles, and in practice, one or more of the limited lifting thimbles may be lifted due to aging of the mechanism. Incomplete or delayed or even impossible to lift, which may further cause the substrate to be tilted or lifted incompletely, causing damage to the substrate and the plasma processing substrate.

Accordingly, there is a need in the art for a de-clamping mechanism that is capable of reliably and stably holding a substrate from an electrostatic chuck, and the present invention is based on this.

In view of the above problems in the background art, the present invention provides a plasma processing chamber and a de-clamping apparatus and method therefor.

A first aspect of the present invention provides a plasma processing chamber, comprising: a cavity; a base disposed under the cavity, the substrate being placed on the surface of the base; and disposed inside the base a plurality of cooling gas passages through which a cooling gas is passed, the cooling gas passage being provided with a gas injection hole between the base and the substrate, wherein the cooling gas can spray cooling gas to the back surface of the substrate through the gas injection holes; a plurality of lifting thimbles that are movably disposed inside the abutment and capable of lifting up the substrate upwards The electric chuck is located at an upper portion of the base, and an upper layer is provided with an insulating layer, and an electrode is disposed in the insulating layer, wherein the electrodes are respectively connected with a DC power source and an AC power source.

Further, a cooling gas supply device is disposed below the base station, and the cooling gas supply device is connected to the cooling gas passage for supplying cooling gas to the cooling gas passage.

Further, the cooling gas includes helium.

Further, a lifting device is further disposed under the base, which is connected to the lifting ejector pin, and lifts the lifting ejector pin so that the lifting device contacts the back surface of the substrate, thereby driving the substrate upward mobile.

Further, the lifting device includes an air pump or the like.

Further, the electrode is connected to a power supply device.

Further, the power supply device includes a double-shock switch and a DC power supply in parallel, wherein the double-shock switch is triggered by a control signal.

Further, the power supply device includes a control switch, a DC power source, and an AC power source, wherein an output end of the control switch is connected to the electrode, and two input terminals are respectively connected to the DC power source and the AC power source.

A second aspect of the invention provides a substrate de-clamping method for a plasma processing chamber, wherein the plasma processing chamber comprises the plasma processing chamber of the first aspect of the invention, wherein The method of clamping includes the steps of: applying a reverse DC voltage to the electrodes in the base of the plasma processing chamber after the end of the main processing stage of the substrate; and then applying an alternating voltage to the electrodes, in the process Continuously supplying cooling gas to the back surface of the substrate; Next, when the cooling gas leak rate continues for a first time not less than a predetermined threshold, it is determined that the substrate has been de-clamped.

Further, the reverse DC voltage ranges from 200V to 300V, and the duration of applying the reverse DC voltage is 3s to 5s.

Further, the alternating voltage is 150v.

Further, the alternating voltage is applied at a frequency of 0.1 hz to 1 hz.

Further, the cooling gas is helium.

The plasma processing chamber and the removing device and method thereof provided by the invention can effectively solve the problem of de-clamping failure caused by the residual charge problem on the substrate or the electrostatic chuck, and can solve the problem that the substrate portion is removed by clamping. Misjudgment.

The specific embodiments of the present invention will be further described by the following examples and the accompanying drawings.

100‧‧‧ Plasma processing unit

101‧‧‧ chamber

102‧‧‧ gas source

103‧‧‧ gas sprinkler

104‧‧‧Insulation

105‧‧‧DC electrode

106‧‧‧Abutment

108‧‧‧vacuum pump

109‧‧‧High voltage DC power supply

112‧‧‧Electrostatic chuck

200‧‧‧ plasma processing chamber

201‧‧‧ cavity

202‧‧‧ gas source

203‧‧‧ gas sprinkler

204‧‧‧Insulation

205‧‧‧DC electrode

206‧‧‧Abutment

207‧‧‧Cooling gas passage

207a‧‧‧jet hole

208‧‧‧vacuum pump

209‧‧‧Power supply unit

2091‧‧‧Double shock switch

2092‧‧‧DC power supply

2093‧‧‧Control switch

2094‧‧‧DC power supply

2095‧‧‧AC power supply

210‧‧‧Cooling gas supply

211‧‧‧Control device

212‧‧‧Electrostatic chuck

213a‧‧‧First lift thimble

213b‧‧‧Second lift thimble

213c‧‧‧ third lift thimble

214‧‧‧ lifting device

W‧‧‧ substrates

A‧‧‧ control signal

[Fig. 1a] is a schematic diagram of the principle of using a DC power source for the plasma processing device to be clamped; [Fig. 1b] is a schematic diagram of a DC power supply voltage, a helium gas pressure, and a flow rate thereof, which are clamped by a DC power source for a plasma processing device; 2] is a schematic structural view of a plasma processing chamber according to an embodiment of the present invention; [FIG. 3] is a schematic structural view of a lifting ejector of a plasma processing chamber according to an embodiment of the present invention; Is a schematic structural view of a lifting ejector of a plasma processing chamber according to an embodiment of the present invention; [Fig. 5] is a schematic diagram of a DC power supply voltage, a helium gas pressure, and a flow rate thereof, which are clamped by a DC power source for a plasma processing apparatus according to an embodiment of the present invention; [Fig. 6] is a diagram of a specific embodiment according to the present invention. A schematic diagram of a control circuit structure of a plasma processing chamber; [Fig. 7] is a schematic structural view of a control circuit of a plasma processing chamber according to an embodiment of the present invention.

Specific embodiments of the present invention will be described below with reference to the accompanying drawings.

Embodiments of the present invention provide an improved de-clamping process that employs a lifting ejector pin to reduce the likelihood of damage to the semiconductor substrate during the de-chucking process. It is to be noted that the terms "semiconductor substrate", "wafer" and "substrate" may be used interchangeably in the following description. In the present invention, they all refer to a substrate that is processed in a processing chamber. The sheet, the substrate is not limited to a substrate, a substrate, a substrate, a large-area flat substrate, or the like. For convenience of description, the present patent will be exemplarily described by taking "substrate" as an example in the description and illustration of the embodiments.

Figure 1a is a schematic diagram of the principle of using a DC power supply to clamp the plasma processing device. As shown in Fig. 1a, in the plasma processing apparatus 100, an electrostatic chuck (not shown) fixes or holds the substrate W by electrostatic force during the manufacturing process. A DC electrode 105 is connected to a high voltage DC power source 109 to generate an electrostatic charge of opposite polarity between the electrostatic chuck and the substrate W, thereby generating an electrostatic clamping force. Further, the reaction gas enters the chamber 101 from the gas source 102 through the gas shower head 103, and the DC electrode 105 is disposed in the insulating layer 104 at the top of the base 106. The reaction gas is plasma generated by the excitation of the electric field in the chamber 101 to process the substrate W, and the process redundancy is evacuated from the chamber by the vacuum pump 108. Reference numeral 112 indicates an electrostatic chuck, and the electrostatic chuck 112 is disposed on the top of the base.

After the process is completed, the substrate needs to be removed or "de-chucked" from the chuck. In order to achieve the clamping, the high voltage DC power source 109 is turned off. However, since the residual charge tends to stay on the back of the entire substrate W or a part of the back surface of the substrate W, the lift on the electrostatic chuck When the thimble is lifted up from the substrate, the substrate often cannot be separated from the electrostatic chuck and can be broken into pieces or cause other damage.

In the prior art, engineers have attempted to achieve de-clamping in different ways, such as by applying a reverse polarity discharge voltage to the DC electrode 105 and/or providing an outlet for residual charge.

FIG. 1b is a schematic diagram of a DC power supply voltage, a helium gas pressure, and a flow rate thereof, which are clamped by a DC power source for a plasma processing apparatus. Fig. 1b shows three coordinate axes from top to bottom, respectively, whose abscissas represent time, and the ordinates from top to bottom respectively indicate: the voltage value of the DC electrode 105 and its positive and negative direction (HV), the helium gas pressure value ( He pressure), He flow.

Referring to Figures 1a and 1b, those skilled in the art will appreciate that in the plasma etching process, the substrate W is electrostatically attracted to the electrostatic chuck by a DC electrode 105. Generally, when the substrate W is transferred to the surface of the electrostatic chuck provided in the reaction chamber, at the time t10 as shown in FIG. 1b, one of the first steps in the process start is to add a low-power RF signal to generate in the cavity. The plasma thereby generates an electrical circuit, and then a DC high voltage is applied to the DC electrode 105 buried in the ceramic layer of the electrostatic chuck to cause electrostatic force on the surface of the electrostatic chuck and the surface of the substrate W. When the electrostatic force reaches the steady state at time t11, helium gas of a certain pressure is applied to the back surface of the substrate W as a cooling gas. The back pressure of helium is determined by the process requirements, and the magnitude of the DC high voltage that causes the substrate W to adsorb to the surface of the electrostatic chuck is determined by the back pressure of the helium gas. During the entire process of the process, the DC high voltage applied to the DC electrode 105 is maintained to counter the upward pressure exerted by the helium back pressure on the substrate W. At the time t12 before the end of the process, the helium back pressure and the DC high voltage applied to the electrostatic chuck are simultaneously lowered, and the DC high voltage applied to the DC electrode 105 in the electrostatic chuck 112 is reversed to remain in the electrostatic chuck. The charge on the surface of the surface or substrate W (mainly referred to as the substrate whose surface material is the medium) is released. At the subsequent t13, the DC voltage is lowered to 0, waiting for the complete release of the residual electrostatic force. The criterion for determining whether or not the participating electrostatic force is completely released is that the helium leak rate is not less than a certain value for several consecutive seconds. For example, as shown in Figure 1b, from t14 to t15 When the engraving gas continuously exceeds a certain threshold, it is considered that the substrate W has been clamped, and thereafter the robot outside the chamber is instructed to enter the chamber to pre-treat the substrate W from above the electrostatic chuck out of the chamber.

However, in the above-mentioned de-chucking process, if the applied reverse DC voltage is not high enough or the time is too short, the residual charge of the dielectric layer on the surface of the electrostatic chuck or the surface of the substrate W is difficult to be completely released, resulting in de-clamping. The time is longer and it is even harder to hold. If the applied reverse DC voltage is too high or the time is too long, the substrate W is sucked in the reverse direction, which also causes the de-clamping time to become longer or difficult to clamp. As the use time of the electrostatic chuck increases, the surface will age, that is, the characteristics of the roughness, the composition and structure of the surface material change, resulting in electrical changes. Typically, this change will cause the release of residual charge after the end of the main process step to vary with the history of its use. Therefore, different main process steps in different processes and different usage history of the electrostatic chuck may cause the size and time setting of the reverse voltage in the de-clamping step to be difficult to optimize.

Based on this, the present invention proposes an improved substrate de-clamping mechanism. It should be noted that the substrate de-clamping mechanism of the present invention will be described below in connection with a plasma processing chamber (typically an etching machine). However, it will be understood by those skilled in the art that the present invention is also applicable to all equipment that requires clamping and unclamping of a substrate, such as a chemical vapor deposition machine.

2 is a schematic view of the structure of a plasma processing chamber in accordance with an embodiment of the present invention. The plasma processing chamber 200 has a processing chamber 201, the processing chamber 201 is substantially cylindrical, and the processing chamber sidewall is substantially vertical, and the processing chamber 201 has upper electrodes disposed in parallel with each other (not shown, disposed In the gas shower head 203) and the lower electrode (not shown, disposed in the base 206). The reaction gas is piped from the gas source 202 to the gas shower head 203 connected to the upper portion of the cavity 201. Typically, the area between the upper and lower electrodes is the processing area that will form high frequency energy to excite the reactive gases, creating and maintaining the plasma. A substrate W to be processed is placed over the electrostatic chuck, which may be a semiconductor substrate to be etched or processed or a glass plate to be processed into a flat panel display. Wherein, the electrostatic chuck is used to clamp the substrate W. The reaction gas is input from the gas source 202 into the processing chamber 201, One or more RF power sources may be separately applied to the lower electrode or simultaneously applied to the upper and lower electrodes, respectively, for delivering RF power to the lower electrode or to the upper and lower electrodes, thereby A large electric field is generated inside 102. Most of the electric field lines are contained in a processing region between the upper electrode and the lower electrode, which accelerates a small amount of electrons present inside the processing chamber 201 to collide with gas molecules of the input reaction gas. These collisions result in ionization of the reactive gas and excitation of the plasma, thereby producing plasma in the processing chamber 201. The neutral gas molecules of the reactive gas lose electrons when subjected to these strong electric fields, leaving positively charged ions. The positively charged ions accelerate toward the lower electrode and combine with the neutral species in the substrate being processed to excite substrate processing, i.e., etching, deposition, and the like. An exhaust region is provided at a suitable location of the plasma processing chamber 200, the exhaust region being coupled to an external exhaust device (eg, vacuum pump 208) for use of the spent reactant gas during processing And by-product gas extraction chamber.

As shown in FIG. 2, the plasma processing chamber 200 further includes a plurality of cooling gas passages 207 disposed inside the base 206, wherein a cooling gas is passed through, and a cooling gas passage 207 is formed on the base 206 and the base. A gas injection hole 207a is provided between the sheets W, and the cooling gas can spray the cooling gas to the back surface of the substrate W through the gas injection holes 207a.

As shown in FIGS. 3 and 4, the plasma processing chamber 200 further includes a plurality of lifting thimbles movably disposed inside the base 206, which are capable of passing through the top of the electrostatic chuck 212 at the top of the base 206. The insulating layer 204 is further lifted to the back surface of the substrate W to lift the substrate W upward. In the present embodiment, the plasma processing chamber 200 is provided with three lifting thimbles, a first lifting ejector pin 213a, a second lifting ejector pin 213b, and a third lifting ejector pin 213c. It should be noted that the number of lifting thimbles of the present embodiment is not considered to be a limitation of the present invention, and the number of lifting thimbles can be set as needed in actual operation.

The electrostatic chuck 212 is located at an upper portion of the base 206, and an uppermost layer is provided with an insulating layer 204, and a DC electrode 205 is disposed in the insulating layer, wherein the DC electrode 205 is respectively connected with a DC power supply and an AC power supply. As shown in FIG. 2, the DC power source and the AC power source are disposed in the power supply device 209, and the relevant portions of the power supply device 209 will be described in detail in the relevant portions below.

Further, a cooling gas supply device 210 is further disposed under the base 206, and the cooling gas supply device 210 is connected to the cooling gas passage through at least two connecting passages. The two connecting passages are respectively used for recovering the cooling gas to the cooling gas supply device 210 and supplying the cooling gas to the cooling gas passage, thereby realizing the cooling gas supply device 210 to circulate and supply the cooling gas to the cooling gas passage. Typically, in the present embodiment, the cooling gas comprises helium.

Further, a lifting device 214 is further disposed under the base 206, and is connected to the first lifting ejector pin 213a, the second lifting ejector pin 213b, and the third lifting ejector pin 213c, and lifting the first lifting ejector pin The 213a, the second lift ejector pin 213b, and the third lift ejector pin 213c cause the lift device to contact the back surface of the substrate W, thereby causing the substrate W to move upward. Typically, in the present embodiment, the lifting device 214 includes an air pump or the like.

It should be noted that both the cooling gas supply device and the lifting device have mature technical support in the prior art, and for brevity, no further details are provided herein.

Further, the plasma processing chamber 200 is further provided with a control device 211 connected to the power supply device 209 and the cooling gas supply device 210 and the lifting device 214, respectively, to control the application of the DC power source and the AC power source, and the supply of the cooling gas. And the lifting of the lifting thimble.

FIG. 5 is a schematic diagram of a DC power supply voltage, a helium gas pressure, and a flow rate for clamping a plasma processing device using a DC power supply, in accordance with an embodiment of the present invention. FIG. Fig. 5 shows three coordinate axes from top to bottom, respectively, whose abscissas represent time, and the ordinates from top to bottom respectively indicate: the voltage value of the DC electrode 205 and its positive and negative direction (Hv), the value of the helium gas pressure ( He Pressure), He flow. In the plasma etching process, the substrate W is fixed to the electrostatic chuck by the electrostatic attraction generated by a DC electrode 205. Usually, after the substrate W is transferred to the surface of the electrostatic chuck provided in the reaction chamber, At the time t02 shown in FIG. 5, one of the first steps in the process start is to add a low-power RF signal, generate plasma in the cavity to generate an electrical circuit, and then feed the DC electrode 205 buried in the ceramic layer of the electrostatic chuck. A large enough DC high voltage is applied to cause electrostatic force on the surface of the electrostatic chuck and the surface of the substrate W. When the electrostatic force reaches the stable time t12, helium gas of a certain pressure is applied to the back surface of the substrate W as a cooling gas. The back pressure of helium is determined by the process requirements, and the magnitude of the DC high voltage that causes the substrate W to adsorb to the surface of the electrostatic chuck is determined by the back pressure of the helium gas. During the entire process of the process, the DC high voltage applied to the DC electrode 205 of the electrostatic chuck is maintained to counter the upward pressure exerted by the helium back pressure on the substrate W. At the time t22 before the end of the process, the helium back pressure and the DC high voltage applied to the electrostatic chuck are simultaneously lowered, and the DC high voltage applied to the DC electrode 205 is reversed so as to remain on the surface of the electrostatic chuck or the substrate W. The charge on the surface of the substrate (mainly referred to as the substrate of the medium) is released.

Then, as shown in FIG. 5, the present invention provides a mechanism for detaching the substrate from the surface of the electrostatic chuck. Specifically, only a short time of reverse DC voltage is applied in the de-clamping step after the end of the main etching step, that is, the stages t22 to t23 as shown. A small alternating voltage is applied during the subsequent period from t23 to t26, such that a small alternating voltage is equivalent to applying a certain frequency of oscillating force to the substrate W, and gradually releasing the charge remaining on the surface of the electrostatic chuck or the surface of the substrate W to O potential until it is determined that the clamping is successful. As for judging the success of the clamping, the reference leak rate is not less than a certain value for several consecutive seconds. For example, as shown in FIG. 5, when the helium gas continuously exceeds a certain threshold from t24 to t25, it is considered that the substrate W has been clamped, and thereafter the robot outside the chamber is instructed to enter the chamber to pre-process the substrate W. Remove the outside of the chamber from the electrostatic chuck.

According to the de-clamping mechanism of the present invention, regardless of whether the applied reverse DC voltage is insufficient or excessive, the residual charge on the surface of the electrostatic chuck is reduced with time so as to be completely neutralized, thereby finally achieving the purpose of de-clamping. In addition to this, the de-clamping mechanism provided by the present invention can also avoid the misjudgment caused by the partial clamping of the substrate W in the prior art.

Figure 6 is a block diagram showing the structure of a control circuit of a plasma processing chamber in accordance with an embodiment of the present invention. As shown, the power supply unit 209 includes a double-shock switch 2091 and a DC power supply 2092 connected in parallel, wherein the double-shock switch 2091 is triggered by a control signal a. Wherein, when the switch of the double-shock switch 2091 is in the position shown in FIG. 6, a DC voltage is supplied to the DC electrode 205. When an alternating voltage is applied to the direct current electrode 205, the double-shock switch 2091 is realized by changing the magnitude and direction of the direct current power supply 2092 and the switching swing of the double-shock switch 2091. Specifically, whether the DC voltage or the AC voltage is applied to the power supply device as shown in FIG. 6 is determined by the control signal a. The structure and function of the double-shock switch have mature technical support in the prior art, and will not be described again for the sake of brevity.

7 is a schematic diagram showing the structure of a control circuit of a plasma processing chamber according to an embodiment of the present invention. The power supply unit 209 includes a control switch 2093, a DC power supply 2094, and an AC power supply 2095, wherein the output of the control switch 2093 is output. The DC electrode 205 is connected to the DC power source 2094 and the AC power source 2095. The invention realizes mutual switching of the direct current voltage and the alternating current voltage by controlling the difference between the output terminals of the switch 2093.

A second aspect of the present invention provides a substrate de-clamping method for a plasma processing chamber 200, wherein the de-clamping method includes the steps of: after the end of the main process stage of the substrate W, to the plasma The DC electrode 205 in the base 206 of the processing chamber 200 applies a reverse DC voltage; then, an alternating voltage is applied to the DC electrode 205, and in the above process, the cooling gas is continuously supplied to the back surface of the substrate W; When the cooling gas leak rate continues for a first time not less than a predetermined threshold, it is determined that the substrate has been de-clamped.

Further, the reverse DC voltage ranges from 200V to 300V, and the duration of applying the reverse DC voltage is 3s to 5s.

Further, the alternating voltage is 150v.

Further, the alternating voltage is applied at a frequency of 0.1 hz to 1 hz. It should be noted that the frequency of the alternating voltage should be between 1 and 50 Hz, and the period should be greater than the relaxation time of the charge polarization of the dielectric layer of the electrostatic chuck (ie, the insulating layer 204 disposed at the uppermost layer of the base 206), otherwise remaining in the The charge on the surface of the electrostatic chuck media is too late to respond and cannot be removed.

Although the present invention has been described in detail by the preferred embodiments thereof, it should be understood that the foregoing description should not be construed as limiting. Various modifications and alterations of the present invention will be apparent to those skilled in the art. Accordingly, the scope of the invention should be defined by the appended claims. In addition, any reference signs in the claim should not be construed as limiting the claim. The term "comprising" does not exclude the other claim or the means or steps not listed in the specification; "first", " Words such as "two" are used only to denote a name, and do not denote any particular order.

200‧‧‧ plasma processing chamber

201‧‧‧ cavity

202‧‧‧ gas source

203‧‧‧ gas sprinkler

204‧‧‧Insulation

205‧‧‧DC electrode

206‧‧‧Abutment

207‧‧‧Cooling gas passage

207a‧‧‧jet hole

208‧‧‧vacuum pump

209‧‧‧Power supply unit

210‧‧‧Cooling gas supply

211‧‧‧Control device

212‧‧‧Electrostatic chuck

W‧‧‧ substrates

Claims (13)

A plasma processing chamber, comprising: a cavity; a base disposed under the cavity, a substrate placed on the surface of the base; and a plurality of cooling gas passages disposed inside the base, wherein Passing a cooling gas, the cooling gas passage is provided with a gas injection hole between the base and the substrate, the cooling gas is capable of spraying cooling gas through the gas injection hole toward the back surface of the substrate; and a plurality of lifting thimbles Removably disposed inside the base, capable of lifting up the substrate, the electrostatic chuck, located at an upper portion of the base, the uppermost layer is provided with an insulating layer, and an electrode is disposed in the insulating layer, wherein The electrodes are controlled to be interconnected with a DC power source and an AC power source, respectively. The plasma processing chamber of claim 1, wherein a cooling gas supply device is further disposed under the base, the cooling gas supply device being coupled to the cooling gas passage for the cooling gas passage Supply cooling gas. The plasma processing chamber of claim 2, wherein the cooling gas comprises helium. The plasma processing chamber of claim 1, wherein a lifting device is further disposed below the base, coupled to the lifting ejector, and lifting the lifting ejector such that the lifting device contacts the The back side of the substrate, thereby driving the substrate to move upward. The plasma processing chamber of claim 4, wherein the lifting device comprises an air pump or the like. A plasma processing chamber according to claim 1, wherein said electrode is connected to a power supply unit. A plasma processing chamber according to claim 6, wherein said power supply means comprises a double-shock switch and a DC power supply in parallel, wherein said double-shock switch is triggered by a control signal. The plasma processing chamber of claim 6, wherein the power supply device comprises a control switch, a direct current power source, and an alternating current power source, wherein an output end of the control switch is connected to the electrode, and two input ends are respectively connected DC power and AC power. A substrate de-clamping method for a plasma processing chamber, wherein the plasma processing chamber includes the plasma processing chamber of any one of claims 1 to 8, wherein the de-clamping The method includes the steps of: applying a reverse DC voltage to an electrode in a base of the plasma processing chamber after the end of the main processing stage of the substrate; and then applying an alternating voltage to the electrode, in the process The back surface of the substrate is supplied with a cooling gas; then, when the cooling gas leak rate continues for a first time not less than a predetermined threshold, it is judged that the substrate has been removed. The de-clamping method of claim 9, wherein the reverse DC voltage ranges from 200V to 300V, and the duration of applying the reverse DC voltage is 3s to 5s. The de-clamping method of claim 9, wherein the alternating voltage is 150v. The de-clamping method of claim 9, wherein the alternating voltage is applied at a frequency of 0.1 hz to 1 hz. The de-clamping method of claim 9, wherein the cooling gas is helium.