Electrostatic chucks and plasma treatment devices

Abstract

This invention provides an electrostatic chuck and plasma processing device, belonging to the field of plasma processing. It mainly includes a ceramic disc with adsorption electrodes; a conductive cover plate detachably mounted to the ceramic disc, with a dielectric layer on the upper surface of the conductive cover plate for supporting a substrate; the adsorption electrodes are connected to a high-voltage DC power supply, and the conductive cover plate is connected to a bias DC power supply. An isolation circuit is provided between the two power supplies to prevent interference. This invention extends the overall lifespan of the electrostatic chuck, ensures stable fixation of the conductive cover plate and substrate during the process, and allows the bias DC power supply to adjust the plasma processing during the process.

Description

Technical Field

[0001] This invention relates to the field of plasma etching technology, and more particularly to the field of electrostatic chuck and plasma treatment device. Prior Technology

[0002] Microfabrication of semiconductor substrates is a well-known technique used to manufacture, for example, semiconductors, flat panel displays, light-emitting diodes (LEDs), and solar cells. A crucial step in microfabrication is the plasma processing step, which takes place inside a sealed chamber where process gases are introduced. An radio frequency (RF) source, coupled to the sealed chamber via inductance and / or capacitance, excites the process gases to form and maintain plasma. Inside the sealed chamber, the exposed substrate is supported by electrostatic chucks and held in place by electrostatic clamping force on the upper surface of the chucks, ensuring substrate safety and a high yield rate during the process.

[0003] With the increasing demand for high aspect ratio etching, a bias voltage needs to be applied to the plasma to enhance the etching depth of charged particles on the substrate surface. The power of the bias voltage supply increases with the aspect ratio of the etched target. When the capacitance between the bias electrode and the substrate is small, the high-power bias voltage supply will cause a large voltage difference between the bias electrode and the substrate, resulting in arcing, which can damage or even render the electrostatic chuck unusable. Therefore, the capacitance between the bias electrode and the substrate cannot be too small. In addition, the surface of the electrostatic chuck will be worn down during the plasma etching process, so the entire electrostatic chuck needs to be replaced periodically. The high price of the electrostatic chuck will increase the manufacturing cost of semiconductor wafers. Summary of the Invention

[0004] To address the high cost of replacing electrostatic chucks while simultaneously ensuring the high aspect ratio etching process, this invention provides an electrostatic chuck for fixing a substrate during plasma processing, comprising: A ceramic disc containing adsorption electrodes; A conductive cover plate, detachably mounted on the upper surface of the ceramic disk, has a dielectric layer fixedly disposed on its upper surface, the upper surface of which serves to support the substrate; and The adsorption electrode is electrically connected to a high-voltage DC power supply, and the conductive cover plate is electrically connected to a bias DC power supply. An isolation circuit is provided between the high-voltage DC power supply and the bias DC power supply to ensure that the substrate and the conductive cover plate are adsorbed above the ceramic disk and to isolate the mutual interference between the high-voltage DC power supply and the bias DC power supply.

[0005] Optionally, the output terminals of the high-voltage DC power supply and the bias DC power supply have the same polarity, and the isolation circuit includes: An isolation capacitor located between the conductive cover plate and the bias DC power supply; An isolation diode is provided, with one end connected between the conductive cover plate and the isolation capacitor, and the other end connected between the adsorption electrode and the high-voltage DC power supply. The isolation diode prevents the conduction from the bias DC power supply to the high-voltage DC power supply.

[0006] Optionally, the isolation circuit further includes an isolation resistor connected in series with the adsorption electrode.

[0007] Optionally, the adsorption electrode and the conductive cover plate are equivalent to a second capacitor, and the product of the resistance of the isolation resistor and the capacitance of the second capacitor is greater than half of the period of the bias DC power supply.

[0008] Optionally, the capacitance between the substrate and the conductive cover plate is equivalent to a first capacitor, the capacitance between the adsorption electrode and the conductive cover plate is equivalent to a second capacitor, and the value of the isolation capacitor is greater than the first capacitor and / or the second capacitor.

[0009] Optionally, the capacitance between the substrate and the conductive cover plate is equivalent to a first capacitor, and the capacitance between the adsorption electrode and the conductive cover plate is equivalent to a second capacitor, wherein the value of the first capacitor is greater than the value of the second capacitor.

[0010] Optionally, the value of the first capacitor is between 5nF and 100nF; the value of the second capacitor is between 1nF and 10nF.

[0011] Optionally, an RF filter is provided between the conductive cover plate and the bias DC power supply.

[0012] Optionally, the radio frequency filter is disposed between the conductive cover plate and the isolation circuit, and the edge of the conductive cover plate extends downward to the plane where the adsorption electrode is located.

[0013] Optionally, the value of the radio frequency filter is between 100nH and 10μH.

[0014] Optionally, the value of the isolation capacitor is between 1nF and 100nF.

[0015] Optionally, the voltage output range of the high-voltage DC power supply is 100V~10kV.

[0016] Optionally, the bias DC power supply is a pulsed DC power supply with a voltage output greater than 1kV, a duty cycle range of 5% to 95%, and a frequency of 1kHz to 10MHz.

[0017] Optionally, the bias DC power supply is an RF DC power supply with a frequency range of 10kHz to 100MHz and a power of 100W to 200kW.

[0018] Optionally, the material of the ceramic disc may include one or more of alumina, silicon carbide, silicon oxide, or sapphire.

[0019] Optionally, the material of the conductive cover plate may include one or more of silicon, metal, and silicon carbide doped with phosphorus or boron.

[0020] Optionally, the material of the dielectric layer may include one or more of alumina, silicon carbide, silicon oxide, or sapphire.

[0021] Furthermore, the present invention also discloses a plasma treatment apparatus, comprising: Processing cavity; A base located within the processing cavity, with an electrostatic chuck of any of the above types fixedly connected to its upper side; The air intake structure located above the processing chamber is used to introduce process gas; A radio frequency source, electrically connected to the base, is used to excite plasma.

[0022] Optionally, the high-voltage DC power supply is located outside the processing chamber, and its output end passes through the bottom wall, base, and lower part of the ceramic disk of the processing chamber before being electrically connected to the adsorption electrode; the bias DC power supply is located outside the processing chamber, and its output end passes through the bottom wall, base, and ceramic disk of the processing chamber before being electrically connected to the conductive cover plate.

[0023] Optionally, the lower side of the base includes a mounting plate, and the isolation circuit is mounted on the lower side of the mounting plate in the form of a circuit board.

[0024] At least one of the above technical solutions has the following advantages or beneficial effects: This invention provides an electrostatic chuck structure. By dividing the insulating material layer on the upper part of a traditional electrostatic chuck into a replaceable upper conductive cover and a fixed lower ceramic disk, the electrostatic chuck can be partially disassembled and replaced. Since components such as the adsorption electrode and heating electrode are located in the fixed lower ceramic disk, only the upper conductive cover needs to be frequently replaced, thus reducing the trial cost during long process cycles. Furthermore, because the traditional insulating material layer is divided, only a controllable thin dielectric layer needs to be set on the upper surface of the conductive cover to support the substrate, significantly increasing the capacitance between the conductive cover and the substrate. Thus, when the bias power supply is applied to the conductive cover, the voltage between the conductive cover and the substrate can be lower, reducing the probability of accidental discharge. At the same time, because the capacitance between the two is increased, the power loss of the bias radio frequency is smaller, enabling higher utilization of the plasma sheath bias. In addition, by setting an isolation circuit between the bias DC power supply and the high-voltage DC power supply, it can be ensured that, while achieving the above technical effects, both the substrate and the conductive cover can be stably adsorbed on the electrostatic chuck. Simple Explanation of the Diagram

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without making any progress. Figure 1 is a schematic diagram of the structure of a plasma treatment device according to an embodiment of the present invention; Figure 2 is a schematic diagram of an electrostatic chuck structure according to an embodiment of the present invention; Figure 3 is a schematic diagram of another embodiment of the electrostatic chuck structure; Figure 4 is a schematic diagram of an isolation circuit according to an embodiment of the present invention; Figure 5 is a schematic diagram of an isolation circuit according to another embodiment of the present invention; Figure 6 is a graph of the adsorption voltage measured by the power supply parameters of the present invention. Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making progressive efforts are within the scope of protection of the present invention.

[0027] To address the high replacement cost of electrostatic chucks while simultaneously achieving high aspect ratio etching and stable substrate adsorption, this invention discloses an electrostatic chuck, primarily comprising: a ceramic disk with adsorption electrodes, which is reusable and does not require frequent replacement; a conductive cover plate detachably mounted on the upper surface of the ceramic disk, with a dielectric layer on its upper surface to support the substrate; since the dielectric layer above the conductive cover plate is more susceptible to damage during the process, the conductive cover plate and dielectric layer can be replaced together after wear, reducing costs compared to replacing the entire electrostatic chuck; and to maintain the adsorption stability of the substrate and conductive cover plate, as well as the plasma etching intensity, while ensuring replaceability, the adsorption electrodes are electrically connected to a high-voltage DC power supply for substrate adsorption, and the conductive cover plate is electrically connected to a bias DC power supply for capacitive adsorption. Furthermore, to prevent mutual interference between the high-voltage DC power supply and the bias DC power supply, an isolation circuit is provided between them.

[0028] Figure 1 shows a schematic diagram of a plasma processing apparatus according to an embodiment of the present invention. This plasma processing apparatus utilizes the principle of capacitive coupling to generate plasma in a reaction chamber via capacitive coupling from a radio frequency power supply applied to an electrode plate, which is then used for etching. It includes a processing chamber 100 surrounded by an outer wall, with an opening on the side wall 101 for accommodating the entry and exit of a substrate. An air intake structure 170 and a base 120 opposite to the air intake structure 170 are provided within the processing chamber. The air intake structure 170 is connected to a gas supply device for supplying reactive gas to the processing chamber 100 and also serves as the upper electrode for activating the plasma. An electrostatic chuck 110 of the present invention is disposed above the base 120, which also serves as the lower electrode for activating the plasma. A reaction region is formed between the upper and lower electrodes. At least one radio frequency source 150 is applied to one of the upper or lower electrodes through a matching network, generating a radio frequency electric field between the upper and lower electrodes to dissociate the reactive gas into plasma. The plasma contains a large number of active particles such as electrons, ions, excited-state atoms, molecules, and free radicals. These active particles can undergo various physical and chemical reactions with the surface of the substrate W to be treated, thereby changing the morphology of the substrate surface and completing the etching process. An exhaust pump 160 is also provided below the processing chamber 100 to discharge reaction byproducts from the reaction chamber and maintain the vacuum environment of the reaction chamber.

[0029] Figure 2 shows a schematic diagram of an electrostatic chuck structure according to an embodiment of the present invention. The electrostatic chuck 110 includes a ceramic disk 111, in which an adsorption electrode 112 is disposed. The ceramic disk 111 is not directly exposed to the plasma during either the process or the cleaning process. Even with multiple plasma treatments, the wear is minimal. Therefore, the ceramic disk 111, along with its internal adsorption electrode 112, can be repeatedly used during the process without frequent replacement. The ceramic disk 111 can be a disc with a certain thickness, and the material can include ceramics such as alumina, sapphire, silicon oxide, and silicon carbide, or a mixture of these materials with other materials.

[0030] A removable conductive cover plate 113 is provided on the upper surface of the ceramic disk 111, and a dielectric layer 114 is fixedly disposed on the upper surface of the conductive cover plate 113. The dielectric layer 114 is used to support the substrate W. During the process, the dielectric layer 114 is more susceptible to plasma corrosion and fails to meet process requirements. In conventional processing, the ceramic disk 111 and its dielectric layer 114, as a whole, need to be removed, polished, and then reinstalled on the base. After several polishing processes, the dielectric layer 114 and the ceramic disk 111 need to be replaced together, thus discarding the ceramic disk 111 and its internal components such as the adsorption electrode 112. In this invention, the conductive cover plate 113 and the dielectric layer 114 can be disassembled and replaced as a whole, extending the service life of the ceramic disk 111 and the adsorption electrode 112. The material of the conductive cover plate 113 may include semiconductors and metals, or conductive substances doped into insulating materials, such as silicon, aluminum, or phosphorus- or boron-doped ceramics. The dielectric layer 114 may include ceramics, such as alumina, silicon carbide, silicon oxide, etc.

[0031] To facilitate the replacement of the conductive cover plate 113, this invention employs a dual adsorption technique for the conductive cover plate 113 and the substrate W. Specifically, the adsorption electrode 112 is electrically connected to a high-voltage DC power supply 115 (see Figures 1 and 2), and the conductive cover plate 113 is electrically connected to a bias DC power supply 116 (see Figures 1 and 2). An isolation circuit 117 is provided between the high-voltage DC power supply 115 and the bias DC power supply 116. Under the action of the isolation circuit 117, the high-voltage DC power supply 115 adsorbs the substrate W onto the upper surface of the dielectric layer 114, and the bias DC power supply 116 adsorbs the conductive cover plate 113 onto the upper surface of the ceramic disk 111. Thus, when both power supplies are turned off, both the substrate W and the conductive cover plate 113 can be easily removed. Furthermore, the isolation circuit prevents mutual interference between the output electrical signals of the high-voltage DC power supply 115 and the bias DC power supply 116, thus avoiding any impact on the adsorption stability of the substrate W or the conductive cover plate 113. Simultaneously, the bias DC power supply 116 inputs an electrical signal onto the conductive cover plate 113, which, after passing through the dielectric layer 114 and the substrate W, acts on the upper plasma sheath layer. The thinner dielectric layer 114 increases the capacitance between the conductive cover plate 113 and the substrate W, resulting in less power loss in the dielectric layer 114 and thus higher power utilization. The reason the dielectric layer 114 can be made thinner is to eliminate concerns about increased costs due to frequent replacement of the entire electrostatic chuck if the dielectric layer 114 is too thin. In the technical solution of this invention, only the conductive cover plate 113 and the dielectric layer 114 need to be replaced.

[0032] The high-voltage DC power supply 115 has a voltage output range of 100V to 10kV. The bias DC power supply 116 can be pulsed or radio frequency (RF). When the bias DC power supply 116 is a pulsed DC power supply, its voltage output is greater than 1kV, its duty cycle ranges from 5% to 95%, and its frequency is from 1kHz to 10MHz. When the bias DC power supply 116 is an RF DC power supply, its frequency range is from 10kHz to 100MHz, and its output power is from 100W to 200kW.

[0033] Figure 4 shows a schematic diagram of an isolation circuit according to an embodiment of the present invention. Specifically, it may include: an isolation capacitor 1172 located between a conductive cover plate 113 and a bias DC power supply 116; and an isolation diode 1171, one end of which is connected between the conductive cover plate 113 and the isolation capacitor 1172, and the other end of which is connected between an adsorption electrode 112 and a high-voltage DC power supply 115. The output terminals of the high-voltage DC power supply 115 and the bias DC power supply 116 have the same polarity, and the isolation diode 1171 prevents conduction from the bias DC power supply 116 to the high-voltage DC power supply 115.

[0034] Specifically, taking the example of the output terminals of both the high-voltage DC power supply 115 and the bias DC power supply 116 in Figure 4 being negative, the positive conduction direction of the diode is from bottom to top as shown in Figure 4. In some other embodiments, when the output terminals of both the high-voltage DC power supply 115 and the bias DC power supply 116 are positive, the positive conduction direction of the diode is from top to bottom. The capacitance between the substrate W and the conductive cover plate 113 is equivalent to the first capacitor C1. The voltage across C1 determines the force by which the substrate W is adsorbed onto the upper surface of the dielectric layer 114. The capacitance between the adsorption electrode 112 and the conductive cover plate 113 is equivalent to the second capacitor C2. The voltage across C2 determines the force by which the conductive cover plate 113 is adsorbed onto the upper surface of the ceramic disk 111. The potential generated by the high-voltage DC power supply 115 across different electrical components is represented on the upper side of the electrical component, and the potential generated by the bias DC power supply 116 across the corresponding electrical component is represented on the lower side of the electrical component. The difference between all potentials is the voltage across the electrical component. As shown in Figure 4, when only the high-voltage DC power supply 115 outputs a negative voltage signal, a positive potential is generated at the left end of capacitor C1 and a negative potential at the right end. Due to the conduction of the isolation diode 1171, no potential is generated across capacitor C2. However, a negative potential is generated at the left end of the isolation capacitor 1172 and a positive potential at the right end. Therefore, the isolation capacitor 1172 ensures that the electrical signal from the high-voltage DC power supply 115 can be applied across capacitor C1, while preventing direct series connection with the bias DC power supply 116, which could damage both power supplies. When the bias DC power supply 116 outputs a negative voltage signal, diode 1171 is cut off. The bias DC power supply 116 generates a positive potential at the left end of the isolation capacitor 1172 and a negative potential at the right end. Due to the action of the isolation diode 1171, a negative potential is generated at the left end of capacitor C2 and a positive potential at the right end, and a positive potential is generated at the left end of capacitor C1 and a negative potential at the right end. This generates voltage across both capacitors C1 and C2, acting as an attraction. At the same time, the voltages generated across C1 by the two power sources have the same polarity, so there is no risk that the voltage across C1 will decrease due to the output of one power source.

[0035] Furthermore, the parallel circuit of DSH, CSH, and ISH represents the equivalent circuit model of the plasma sheath layer on the substrate W surface. The parallel circuit of DW, CW, and IW represents the equivalent circuit model of the plasma sheath layer on the processing cavity wall surface. Rpl represents the resistance inside the plasma. In order to accelerate the bombardment of the substrate by the plasma for a period of time during the etching process, and then expel the charged particles in the substrate structure for a period of time, the signal output by the bias DC power supply 116 needs to be of pulse or radio frequency type. Moreover, only when the signal output by the bias DC power supply 116 is not a continuous single value can it be ensured that the charged particles in the plasma sheath layer will not neutralize the voltage output by the bias DC power supply 116. In order to maintain sufficient voltage across capacitor C2 to attract conductive cover plate 113 when the absolute value of the output voltage of bias DC power supply 116 decreases, in another embodiment, as shown in Figure 5, an isolation resistor 1173 is set on the branch where capacitor C2 is located. In this way, when the output voltage of bias DC power supply 116 decreases or even becomes zero, the RC circuit composed of C2 and isolation resistor 1173 can greatly reduce the discharge rate across C2 and maintain the attraction force.

[0036] In some embodiments, by adjusting the thickness of the dielectric layer 114, the capacitance value of C1 is made greater than that of C2. Since the voltage across C1 comes from two power supplies, a larger capacitance value for C1 ensures that the adsorption force is at a suitable level, preventing excessive damage to the substrate W. Furthermore, a larger C1 also reduces the power loss of the bias DC power supply 116. Meanwhile, in some embodiments, for the same power utilization considerations, the value of the isolation capacitor is greater than the capacitance values ​​of C1 and / or C2. The value of the isolation capacitor can be set between 1nF and 100nF.

[0037] To ensure a stable voltage across C2, the product of the isolation resistor 1173 and the capacitance of C2 can be set to be greater than half the cycle of the bias DC power supply 116.

[0038] Figure 6 shows the adsorption voltage curve measured by the power supply parameters of this invention. The output voltage of the high-voltage DC power source is set to -3kV, and the pulse voltage of the pulse DC power supply is -5kV with a duty cycle of 70%. Applying the isolation circuit of this invention, it can be seen that although the output voltage of the pulse DC power supply changes periodically, the adsorption voltage across C1 and C2 remains almost constant over time.

[0039] In other embodiments, as shown in Figures 3 and 5, the isolation circuit 117 further includes an RF filter 118 disposed between the conductive cover plate 113 and the bias DC power supply 116. Further, the filter 118 can be disposed between the conductive cover plate 113 and the isolation circuit 117 to prevent the RF source 150 that excites the plasma from affecting the bias DC power supply 116 through the conductive cover plate 113. The high-voltage DC power supply 115 can omit the filter due to the shielding effect of the conductive cover plate 113. In this embodiment, the edge of the conductive cover plate 113 can extend downwards to the plane where the adsorption electrode 112 is located to obtain better shielding. The value of the RF filter can be set between 100nH and 10μH. Furthermore, the RF filter can also be a multi-stage low-pass filter or a band-stop filter.

[0040] As shown in Figure 1, in the plasma treatment device provided by the present invention, the ceramic disk 111 of the electrostatic chuck 110 can be fixed to the base 120 by bonding. A mounting plate 130 can be set below the base 120, and the isolation circuit 117 is fixed below the mounting plate 130 in the form of a printed circuit board. The space below the mounting plate 130 is a normal pressure environment and can shield radio frequency, protecting the stability of the electrical components in the isolation circuit. Referring to Figure 3, the high-voltage DC power supply 115 is located outside the processing chamber 100, and its output end passes through the bottom wall of the processing chamber 100, the base 120, and the lower part of the ceramic disk 111 before being electrically connected to the adsorption electrode 112; the bias DC power supply 116 is located outside the processing chamber 100, and its output end passes through the bottom wall of the processing chamber 100, the base 120, and the ceramic disk 111 before being electrically connected to the conductive cover plate 113.

[0041] The electrostatic chuck disclosed in this invention is not limited to capacitively coupled plasma processing devices, but can also be applied to other plasma processing devices, such as inductively coupled plasma processing devices, which will not be elaborated here.

[0042] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims.

[0043] 100: Processing cavity 101: Sidewall 110: Electrostatic chuck 111: Ceramic Plate 112: Adsorption electrode 113: Conductive cover plate 114: Dielectric layer 115: High-voltage DC power supply 116: Bias DC Power Supply 117: Isolation Circuit 118: Radio Frequency Filter 120: Base 130: Mounting plate 150: Radio Frequency Source 160: Exhaust pump 170: Intake Structure 1171: Isolating Diode 1172: Isolation capacitor 1173: Isolation resistor W: Substrate

Claims

1. An electrostatic chuck for fixing a substrate during a plasma process, wherein, include: A ceramic disc containing adsorption electrodes; A conductive cover plate is detachably disposed on the upper surface of the ceramic disk. A dielectric layer is fixedly disposed on the upper surface of the conductive cover plate, and the upper surface of the dielectric layer is used to support the substrate. The adsorption electrode is electrically connected to a high-voltage DC power supply, and the conductive cover plate is electrically connected to a bias DC power supply. An isolation circuit is provided between the high-voltage DC power supply and the bias DC power supply to ensure that the substrate and the conductive cover plate are adsorbed above the ceramic disk and to isolate the mutual interference between the high-voltage DC power supply and the bias DC power supply.

2. The electrostatic chuck as described in claim 1, wherein, The output terminals of the high-voltage DC power supply and the bias DC power supply have the same polarity. The isolation circuit includes: an isolation capacitor located between the conductive cover plate and the bias DC power supply; and an isolation diode, one end of which is connected between the conductive cover plate and the isolation capacitor, and the other end of which is connected between the adsorption electrode and the high-voltage DC power supply. The isolation diode prevents conduction from the bias DC power supply to the high-voltage DC power supply.

3. The electrostatic chuck as described in claim 2, wherein, The isolation circuit also includes an isolation resistor connected in series with the adsorption electrode.

4. The electrostatic chuck as described in claim 3, wherein, The adsorption electrode and the conductive cover plate are equivalent to a second capacitor, and the product of the resistance of the isolation resistor and the capacitance of the second capacitor is greater than half of the cycle of the bias DC power supply.

5. The electrostatic chuck as described in claim 2, wherein, The capacitance between the substrate and the conductive cover plate is equivalent to a first capacitor, the capacitance between the adsorption electrode and the conductive cover plate is equivalent to a second capacitor, and the value of the isolation capacitor is greater than the first capacitor and / or the second capacitor.

6. The electrostatic chuck as claimed in claim 1, wherein, The capacitance between the substrate and the conductive cover plate is equivalent to a first capacitor, and the capacitance between the adsorption electrode and the conductive cover plate is equivalent to a second capacitor. The value of the first capacitor is greater than the value of the second capacitor.

7. The electrostatic chuck as described in claim 6, wherein, The value of the first capacitor is between 5nF and 100nF; the value of the second capacitor is between 1nF and 10nF.

8. The electrostatic chuck as claimed in claim 1, wherein, An RF filter is provided between the conductive cover plate and the bias DC power supply.

9. The electrostatic chuck as described in claim 7, wherein, An RF filter is disposed between the conductive cover plate and the isolation circuit, with the edge of the conductive cover plate extending downward to the plane where the adsorption electrode is located.

10. The electrostatic chuck as claimed in claim 9, wherein, The value of the radio frequency filter is between 100nH and 10μH.

11. The electrostatic chuck as claimed in claim 2, wherein, The value of the isolation capacitor is between 1nF and 100nF.

12. The electrostatic chuck as claimed in claim 1, wherein, The voltage output range of the high-voltage DC power supply is 100V~10kV.

13. The electrostatic chuck as claimed in claim 1, wherein, The bias DC power supply is a pulsed DC power supply with a voltage output greater than 1kV, a duty cycle range of 5% to 95%, and a frequency of 1kHz to 10MHz.

14. The electrostatic chuck as claimed in claim 1, wherein, The bias DC power supply is an RF DC power supply with a frequency range of 10kHz to 100MHz and a power of 100W to 200kW.

15. The electrostatic chuck as claimed in claim 1, wherein, The ceramic disc may be made of one or more of the following materials: alumina, silicon carbide, silicon oxide, or sapphire.

16. The electrostatic chuck as claimed in claim 1, wherein, The material of the conductive cover plate may include one or more of silicon, metal, and silicon carbide doped with phosphorus or boron.

17. The electrostatic chuck as claimed in claim 1, wherein, The material of the dielectric layer may include one or more of aluminum oxide, silicon carbide, silicon oxide, or sapphire.

18. A plasma treatment apparatus, wherein, include: Processing cavity; A base located within the processing cavity, wherein an electrostatic chuck as described in any one of claims 1 to 17 is fixedly connected to the upper side of the base; An air intake structure located above the processing chamber is used to introduce process gas; an radio frequency source, electrically connected to the base, is used to excite plasma.

19. The plasma processing apparatus as claimed in claim 18, wherein, The high-voltage DC power supply is located outside the processing chamber, and its output end passes through the bottom wall, base, and lower part of the ceramic disk of the processing chamber before being electrically connected to the adsorption electrode; the bias DC power supply is located outside the processing chamber, and its output end passes through the bottom wall, base, and ceramic disk of the processing chamber before being electrically connected to the conductive cover plate.

20. The plasma processing apparatus as claimed in claim 18, wherein, The base includes a mounting plate on its lower side, and the isolation circuit is mounted on the lower side of the mounting plate in the form of a circuit board.

Images