CN116436286A - Electrostatic chuck power supply and semiconductor processing apparatus - Google Patents

Electrostatic chuck power supply and semiconductor processing apparatus Download PDF

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Publication number
CN116436286A
CN116436286A CN202310298060.5A CN202310298060A CN116436286A CN 116436286 A CN116436286 A CN 116436286A CN 202310298060 A CN202310298060 A CN 202310298060A CN 116436286 A CN116436286 A CN 116436286A
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China
Prior art keywords
voltage
transformer
diode
tap
circuit
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Pending
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CN202310298060.5A
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Chinese (zh)
Inventor
王松涛
田丰
李玉站
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Beijing Naura Microelectronics Equipment Co Ltd
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Beijing Naura Microelectronics Equipment Co Ltd
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Priority to CN202310298060.5A priority Critical patent/CN116436286A/en
Publication of CN116436286A publication Critical patent/CN116436286A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/32715—Workpiece holder
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
    • H01L21/67—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere
    • H01L21/683—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping
    • H01L21/6831—Apparatus specially adapted for handling semiconductor or electric solid state devices during manufacture or treatment thereof; Apparatus specially adapted for handling wafers during manufacture or treatment of semiconductor or electric solid state devices or components ; Apparatus not specifically provided for elsewhere for supporting or gripping using electrostatic chucks
    • H01L21/6833—Details of electrostatic chucks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0003—Details of control, feedback or regulation circuits
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M1/00—Details of apparatus for conversion
    • H02M1/0083—Converters characterised by their input or output configuration
    • H02M1/009—Converters characterised by their input or output configuration having two or more independently controlled outputs
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33507—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of the output voltage or current, e.g. flyback converters
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of dc power input into dc power output
    • H02M3/22—Conversion of dc power input into dc power output with intermediate conversion into ac
    • H02M3/24—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters
    • H02M3/28—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
    • H02M3/325—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal
    • H02M3/335—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only
    • H02M3/33561—Conversion of dc power input into dc power output with intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac using devices of a triode or a transistor type requiring continuous application of a control signal using semiconductor devices only having more than one ouput with independent control
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Abstract

The embodiment of the invention provides an electrostatic chuck power supply and semiconductor process equipment. The electrostatic chuck comprises a control voltage generation circuit for generating a control voltage according to a user setting value; the boost circuit is used for boosting the control voltage to obtain a high-voltage; the reference voltage introducing circuit is used for providing direct current self-bias voltage which is the voltage difference between the plasma sheath layer and the wafer on the electrostatic chuck, wherein the voltage difference is generated when the semiconductor process equipment executes the process; the positive voltage generating circuit is used for superposing the high-voltage and the direct-current self-bias voltage to generate a positive voltage; and the negative voltage generating circuit is used for reversing the high-voltage and superposing the high-voltage and the direct-current self-bias voltage to generate a negative voltage. The embodiment of the invention can automatically adjust the bias voltage, avoid the influence of the variable-pressure bias on the adsorption force of the electrostatic chuck system, achieve the balance of the adsorption force of the positive electrode and the negative electrode and prevent the adsorption failure phenomenon.

Description

Electrostatic chuck power supply and semiconductor processing apparatus
Technical Field
The invention relates to the technical field of semiconductor production, in particular to an electrostatic chuck power supply and semiconductor process equipment.
Background
In the integrated circuit chip manufacturing industry, the whole process of processing a wafer generally comprises the processes of photoetching, etching, ion implantation, metal deposition, core packaging and the like. In a plasma etching process, an etcher transfers photoresist patterns, such as lines, facets, or holes, created by a photolithography process, to the underlying material of the photoresist without errors, to form the complex architecture that the entire integrated circuit should have. The processes of etching, metal deposition and the like are generally completed by placing a wafer on a chuck in a reaction chamber of semiconductor processing equipment, wherein the chuck plays roles of supporting and fixing the wafer, controlling the temperature of the wafer in the process, and the like. The electrostatic chuck (Electro Static Chuck, ESC) is a chuck structure for fixing a wafer by electrostatic force, and the defects of complicated mechanical chuck structure, reduced effective processing area of the wafer and the like are eliminated. An electrostatic chuck Power supply (ESC DC Power) provides a DC high voltage to the electrostatic chuck to cause the electrostatic chuck to generate an electrostatic force to hold the wafer. The dual electrode electrostatic chuck power supply has two high voltage output ports, a positive high voltage output port (hv+) and a negative high voltage output port (HV-), respectively connected to the two electrodes of the electrostatic chuck. So that the electrostatic chuck can adsorb and fix the wafer. However, with the development of technology and the requirement of increasing etching rate, the power loaded by the lower rf system is larger and larger, so that the absolute values of the voltage differences between the positive electrode and the negative electrode are not equal, and the adsorption forces to the wafer are not equal, so that the adsorption forces of the positive electrode and the negative electrode to the wafer are unbalanced. The adsorption force of the electrode is unbalanced, the adsorption force is weak, the adsorption is not firm, the back-blowing gas can leak in the negative electrode side area, the leakage rate is unqualified, and the technological process is failed.
Disclosure of Invention
In view of the above, embodiments of the present invention have been developed to provide an electrostatic chuck power supply and semiconductor processing apparatus that overcome, or at least partially solve, the above-described problems.
In order to solve the above problems, an embodiment of the present invention discloses an electrostatic chuck power supply applied to a semiconductor process apparatus, the electrostatic chuck power supply being configured to supply power to an chucking electrode of an electrostatic chuck of the semiconductor process apparatus, the electrostatic chuck power supply including:
a control voltage generation circuit for generating a control voltage according to a user setting value;
the boost circuit is used for boosting the control voltage to obtain a high-voltage;
the reference voltage introducing circuit is used for providing direct current self-bias voltage which is the voltage difference between the plasma sheath layer and the wafer on the electrostatic chuck, wherein the voltage difference is generated when the semiconductor process equipment executes the process;
the positive voltage generating circuit is used for superposing the high-voltage and the direct-current self-bias voltage to generate a positive voltage;
and the negative voltage generating circuit is used for reversing the high-voltage and superposing the high-voltage and the direct-current self-bias voltage to generate a negative voltage.
Optionally, the boost circuit includes a first transformer, a primary side of the first transformer is connected to the control voltage generating circuit, and a secondary side of the first transformer is connected to the positive voltage generating circuit and the negative voltage generating circuit.
Optionally, the control voltage generating circuit includes:
and the first square wave voltage generation circuit is used for generating a first square wave voltage signal according to the user setting value, and the first square wave voltage signal is input to the primary side of the first transformer.
Optionally, the first square wave voltage generating circuit includes:
the first pulse width modulation circuit is used for generating a first pulse width modulation signal according to a user setting value;
the control end of the first control switch is connected with the first pulse width modulation circuit, the first end of the first control switch is connected with a first tap of the primary side of the first transformer and a second tap of the primary side of the first transformer, the state of the switch is switched under the triggering of the first pulse width modulation signal, and the second end of the first control switch is grounded;
one end of the first resistor is connected with a preset power supply, a third tap of the primary side of the first transformer and a fourth tap of the primary side of the first transformer, the first tap of the primary side of the first transformer corresponds to the third tap of the primary side of the first transformer, and the second tap of the primary side of the first transformer corresponds to the fourth tap of the primary side of the first transformer;
A first capacitor connected in parallel with the first resistor;
and the cathode of the first diode is connected with the other end of the first resistor, and the anode of the second diode is connected with the first end of the first control switch.
Optionally, the positive electrode voltage generating circuit includes:
one end of the second capacitor is connected with a first tap of the secondary side of the first transformer;
the cathode of the second diode is connected with the other end of the second capacitor;
the anode of the third diode is connected with the other end of the second capacitor and the cathode of the second diode;
one end of the third capacitor is connected with the anode of the second diode, the second tap of the secondary side of the first transformer and the reference voltage introducing circuit, and the other end of the third capacitor is connected with the anode of the second diode and serves as the output end of the anode voltage generating circuit to output the anode voltage;
the second resistor is connected with the third capacitor in parallel; and/or
The negative electrode voltage generation circuit includes:
the positive electrode of the fourth capacitor is connected with the first tap of the secondary side of the first transformer;
The anode of the fourth diode is connected with the cathode of the fourth capacitor;
the cathode of the fifth diode is connected with the cathode of the fourth capacitor and the anode of the fourth diode;
one end of the fifth capacitor is connected with the cathode of the fourth diode and the reference voltage introducing circuit, and the other end of the fifth capacitor is connected with the anode of the fifth diode and is used as an output end of the cathode voltage generating circuit to output the cathode voltage;
and one end of the third resistor is connected with the positive electrode of the fifth diode and the reference voltage introducing circuit, and the other end of the third resistor is connected with the positive electrode of the fifth capacitor, the negative electrode of the fourth diode and the second tap of the secondary side of the first transformer.
Optionally, the reference voltage introducing circuit includes:
the second square wave voltage generating circuit is used for generating a second square wave voltage signal according to the detection value of the direct current self-bias voltage detection circuit;
the main side of the second transformer is connected with the second square wave voltage generating circuit;
and the reference voltage output circuit is connected with the secondary side of the second transformer to generate the direct current self-bias voltage.
Optionally, the second square wave voltage generating circuit includes:
the second pulse width modulation circuit is used for generating a second pulse width modulation signal according to the detection value;
the control end of the second control switch is connected with the second pulse width modulation circuit, the first end of the second control switch is connected with the first tap of the main side of the second transformer and the second tap of the main side of the second transformer, the state of the switch is switched under the triggering of the second square wave voltage signal, and the second end of the second control switch is grounded;
one end of the fourth resistor is connected with a preset power supply, a third tap of the main side of the second transformer and a fourth tap of the main side of the second transformer; the first tap of the main side of the second transformer corresponds to the third tap of the main side of the second transformer, and the second tap of the main side of the second transformer corresponds to the fourth tap of the main side of the second transformer;
a sixth capacitor connected in parallel with the fourth resistor;
the negative electrode of the sixth diode is connected with the other end of the fourth resistor, and the positive electrode of the sixth diode is connected with the first end of the second control switch; or;
The reference voltage output circuit includes:
one end of the seventh capacitor is connected with the first tap of the secondary side of the second transformer;
the anode of the seventh diode is connected with the other end of the seventh capacitor;
one end of the eighth capacitor is connected with the cathode of the seventh diode;
an eighth diode, wherein the anode of the eighth diode is connected with the other end of the eighth capacitor, the positive voltage generating circuit and the negative voltage generating circuit, and the cathode of the eighth diode is connected with the anode of the seventh diode and the other end of the seventh capacitor;
and one end of the fifth resistor is connected with the anode of the eighth diode, the other end of the eighth capacitor, the anode voltage generating circuit and the cathode voltage generating circuit, and the other end of the fifth resistor is connected with the cathode of the seventh diode, one end of the eighth capacitor and the secondary side second tap of the second transformer.
Optionally, the direct current self-bias voltage detection circuit is arranged in a radio frequency matcher of the semiconductor process equipment and is used for detecting a voltage value on an electrode at an output end of the radio frequency matcher to obtain a detection value of direct current self-bias voltage.
The embodiment of the invention also discloses an electrostatic chuck power supply which is applied to the semiconductor process equipment and is used for supplying power to the adsorption electrode of the electrostatic chuck of the semiconductor process equipment, and the electrostatic chuck power supply comprises:
the forward control voltage generation circuit is used for generating a forward control voltage according to the sum of a user set value and a detection value of the direct current self-bias voltage detection circuit, wherein the direct current self-bias voltage is a voltage difference between a plasma sheath layer and a wafer on the electrostatic chuck, which is generated when the semiconductor process equipment executes a process;
a reverse control voltage generation circuit for generating a reverse control voltage according to a sum of a negative value of a user setting value and a detection value of the direct current self-bias voltage detection circuit;
the first boosting circuit is used for boosting the forward control voltage to obtain positive voltage;
and the second boosting circuit is used for boosting the reverse control voltage to obtain a negative electrode voltage.
Optionally, the first boost circuit includes:
the main side of the third transformer is connected with the forward control voltage generation circuit;
the negative electrode of the ninth capacitor is connected with the first tap of the secondary side of the third transformer;
A ninth diode, wherein the cathode of the ninth diode is connected with the anode of the ninth capacitor;
a twelfth diode, wherein the positive electrode of the tenth diode is connected with the positive electrode of the ninth capacitor and the negative electrode of the ninth diode;
a tenth capacitor, one end of which is connected with the positive electrode of the ninth diode, and the other end of which is used as the output end of the first boost circuit to output the positive electrode voltage;
one end of the sixth resistor is connected with the negative electrode of the twelfth electrode tube, the other end of the ninth resistor is connected with the negative electrode of the tenth capacitor, the positive electrode of the ninth diode and the second tap of the secondary side of the third transformer, and the second tap of the secondary side of the third transformer is grounded; or;
the second booster circuit includes:
a fourth transformer, the main side of which is connected with the reverse control voltage generating circuit,
the positive electrode of the eleventh capacitor is connected with the first tap of the secondary side of the fourth transformer;
an eleventh diode, wherein the anode of the eleventh diode is connected with the cathode of the eleventh capacitor;
a twelfth diode, wherein the negative electrode of the twelfth diode is connected with the negative electrode of the eleventh capacitor and the positive electrode of the eleventh diode;
A twelfth capacitor, one end of which is connected with the cathode of the twelfth diode, and the other end of which is connected with the anode of the twelfth diode and is used as the output end of the second booster circuit generating circuit to output the cathode voltage;
and one end of the seventh resistor is connected with the anode of the twelfth diode in a preset manner, the other end of the seventh resistor is connected with the anode of the twelfth capacitor, the cathode of the eleventh diode and the second tap of the secondary side of the fourth transformer, and the second tap of the secondary side of the fourth transformer is grounded.
Optionally, the forward control voltage generating circuit includes:
the third-party-wave voltage generating circuit is used for generating a third-party-wave voltage signal with a preset duty ratio according to the sum of a user setting value and a detection value of the direct-current self-bias voltage detecting circuit, and inputting the third-party-wave voltage signal to the main side of the third transformer; or (b)
The reverse control voltage generation circuit includes:
and the fourth wave voltage generating circuit is used for generating a fourth wave voltage signal with a preset duty ratio according to the sum of the negative value of the user setting value and the detection value of the direct current self-bias voltage detection circuit, and inputting the fourth wave voltage signal to the main side of the fourth transformer.
Optionally, the third-party-wave voltage generating circuit includes:
the third pulse width modulation circuit is used for generating a third pulse width modulation signal according to the sum of the user setting value and the detection value of the direct current self-bias voltage detection circuit;
the control end of the third control switch is connected with the third pulse width modulation circuit, the first end of the third control switch is connected with the first tap of the main side of the third transformer and the second tap of the main side of the third transformer, the state of the switch is switched under the triggering of the third-party wave voltage signal, and the second end of the third control switch is grounded;
one end of the eighth resistor is connected with the preset power supply, the third tap of the main side of the third transformer and the fourth tap of the main side of the third transformer, the first tap of the main side of the third transformer corresponds to the third tap of the main side of the third transformer, and the second tap of the main side of the third transformer corresponds to the fourth tap of the main side of the third transformer;
a thirteenth capacitor connected in parallel with the eighth resistor;
a thirteenth diode, wherein the cathode of the thirteenth diode is connected with the other end of the eighth resistor, one end of the thirteenth capacitor is connected, and the anode of the thirteenth diode is connected with the first end of the third control switch; or;
The fourth-wave voltage generation circuit includes:
the fourth pulse width modulation circuit is used for generating a fourth pulse width modulation signal according to the sum of the negative value of the user setting value and the detection value of the direct current self-bias voltage detection circuit and the sum of the detection value of the direct current self-bias voltage detection circuit;
the control end of the fourth control switch is connected with the fourth pulse width modulation circuit, the output end of the fourth control switch is connected with a first tap of the main side of the fourth transformer and a second tap of the main side of the third transformer, the state of the switch is switched under the triggering of the fourth pulse width modulation signal, and the second end of the fourth control switch is grounded;
one end of the ninth resistor is connected with the preset power supply, the third tap of the main side of the fourth transformer and the fourth tap of the main side of the fourth transformer; the first tap of the main side of the fourth transformer corresponds to the third tap of the main side of the fourth transformer, and the second tap of the main side of the fourth transformer corresponds to the fourth tap of the main side of the fourth transformer;
a fourteenth capacitor connected in parallel with the ninth resistor;
and the negative electrode of the fourteenth diode is connected with the other end of the ninth resistor, one end of the fourteenth capacitor is connected, and the positive electrode of the fourteenth diode is connected with the first end of the fourth control switch.
Optionally, the direct current self-bias voltage detection circuit is arranged in a radio frequency matcher of the semiconductor process equipment and is used for detecting a voltage value on an electrode at an output end of the radio frequency matcher to obtain a detection value of direct current self-bias voltage.
The embodiment of the invention also discloses semiconductor process equipment, which is characterized by comprising a radio frequency power supply, a radio frequency matcher and a process chamber, wherein the process chamber comprises an electrostatic chuck and the electrostatic chuck power supply;
the electrostatic chuck power supply is used for generating positive voltage and negative voltage to the adsorption electrode of the electrostatic chuck so as to carry out electrostatic adsorption on the wafer on the electrostatic chuck;
the radio frequency power supply is used for loading radio frequency power to the electrostatic chuck through the radio frequency matcher so as to generate a plasma sheath layer on the upper surface of the wafer on the electrostatic chuck.
Optionally, the radio frequency matcher includes a direct current self-bias voltage detection circuit, and the direct current self-bias voltage detection circuit is used for detecting a voltage value on an electrode at an output end of the radio frequency matcher to obtain a detection value of direct current self-bias voltage;
the electrostatic chuck power supply is configured to generate a positive voltage and a negative voltage to a chucking electrode of the electrostatic chuck based on the detection value and a user setting value.
The embodiment of the invention has the following advantages:
according to the embodiment of the invention, the positive electrode voltage and the negative electrode voltage are generated based on the direct-current self-bias voltage, so that the influence of the voltage bias on the adsorption force of the electrostatic chuck is automatically compensated, the aim of balancing the adsorption force of the positive electrode and the negative electrode is achieved, and the adsorption failure phenomenon is prevented.
Drawings
FIG. 1 is a schematic diagram of a prior art electrostatic chuck power supply;
FIG. 2 is a schematic block diagram of one embodiment of an electrostatic chuck power supply of the present invention;
FIG. 3 is a schematic diagram of an electrostatic chuck power supply embodiment application of the present invention;
FIG. 4 is a circuit diagram of an embodiment of an electrostatic chuck power supply of the present invention;
FIG. 5 is a schematic block diagram of another embodiment of an electrostatic chuck power supply of the present invention;
FIG. 6 is a circuit diagram of another embodiment of an electrostatic chuck power supply of the present invention;
fig. 7 is a schematic view of an embodiment of a semiconductor processing apparatus of the present invention.
Detailed Description
In order that the above-recited objects, features and advantages of the present invention will become more readily apparent, a more particular description of the invention will be rendered by reference to the appended drawings and appended detailed description.
Referring to fig. 1, a schematic diagram of a conventional electrostatic chuck power supply is shown. The figure also includes the state of the reaction chamber with the double-electrode electrostatic chuck.
The electrostatic chuck comprises a chuck base 5 and a ceramic layer 7, the chuck base 5 and the ceramic layer 7 are arranged in a reaction cavity 9, two electrodes are buried in the ceramic layer 7, the first electrode 4 and the second electrode 8 are made of metal, and the first electrode 4 and the second electrode 8 are electrically insulated from each other because four sides of the electrode are wrapped by the ceramic layer 7. The two high voltage output ports, positive high voltage output port (hv+) 11 and negative high voltage output port (HV-) 13, of the electrostatic chuck power supply 6 are connected to the first electrode 4 and the second electrode 8, respectively, through a filter circuit 10.
The inside of the electrostatic chuck is usually provided with a coolant liquid channel (not shown in the figure), and constant temperature liquid circularly flows in the channel to realize temperature control of the chuck and the wafer. The inside of the electrostatic chuck is also provided with a coolant gas channel (not shown in the figure), a back blowing gas channel is used for controlling coolant gas with certain pressure or flow to blow the lower surface of the wafer, so that the temperature control of the wafer 3 in the process is further realized, when the first electrode 4 of the electrostatic chuck is charged with positive electricity, the second electrode 8 is charged with negative electricity, and the electrostatic chuck generates electrostatic force attraction to fix the wafer 3, thereby preventing the coolant gas from leaking from the lower surface of the wafer 3. 1 is a plasma generating system, generally comprising a radio frequency coil, an upper matcher, an upper radio frequency power supply, which generates a high frequency magnetic field to excite a process gas entering a reaction chamber 9 into a plasma 2.
Reference numeral 14 denotes a lower matching unit, and 15 denotes a lower rf power supply, which generates a high-frequency magnetic field to generate a plasma sheath 18 on the upper surface of the wafer 3, and generates an electric field by a voltage difference (dc self-bias) between the sheath 18 and the wafer 3 to attract various charged particles in the plasma to process the surface of the wafer 3.
The positive charge applied to the first electrode 4 is denoted HV and the negative charge applied to the second electrode 8 is denoted-HV. Under the influence of the electric fields of the positive electrode and the negative electrode, induced charges 16 and 17 appear in corresponding areas on the wafer, and the absolute values of voltages of the induced charges 16 and 17 are theoretically equal because the absolute values of voltages applied to the positive electrode and the negative electrode are equal. When the voltage value of the induced charge 16 is- Δv1, the voltage value of the induced charge 17 is Δv1. The voltage difference +u=hv+Δv1 between the first electrode 4 and the wafer 3, and the voltage difference-u= -HV- Δv1 between the first electrode 8 and the wafer 3.
The larger the electrostatic force F.alpha.U between the electrode and the wafer, the larger the U is. The absolute value of the voltage difference between the positive electrode and the negative electrode is (HV+DeltaV1), and the suction force of the positive electrode and the negative electrode to the wafer is theoretically the same as the suction force of the electrostatic chuck to the wafer, and the suction force of the electrostatic chuck to the wafer is uniformly distributed on the lower surface of the wafer.
When the lower RF system generates a high-frequency magnetic field, the DC self-bias voltage 18 on the wafer 3 is set to-DeltaV (the reference point is ground, the same applies below), and the voltage of the wafer region 16 corresponding to the first electrode 4 is changed from (-DeltaV 1) to (-DeltaV 1-DeltaV); the voltage of the wafer region 17 corresponding to the second electrode 8 is changed from (Δv1) to (Δv1- Δv). The voltage difference +u=hv- (- Δv1- Δv) =hv+Δv1+Δv between the positive electrode and the wafer 3, i.e., +u changes from (hv+Δv1) to (hv+Δv1+Δv), the voltage difference becomes large, and the electrostatic force between the positive electrode and the wafer 3 increases; the voltage difference between the negative electrode and the wafer 3-U '= -HV- (Δv1- Δv) = -HV- Δv1+Δv, i.e. -U' is changed from (-HV- Δv1) to (-HV- Δv1+Δv), the absolute value of the voltage between the negative electrode and the wafer is changed from (hv+Δv1) to (hv+Δv1- Δv), the absolute value becomes smaller, i.e., the voltage difference becomes smaller, and the electrostatic force between the negative electrode and the wafer 3 is weakened.
The absolute values of the voltage differences between the positive electrode and the negative electrode are different, and the adsorption force to the wafer is different, so that the adsorption force of the positive electrode and the negative electrode to the wafer is unbalanced. Along with the development of technology and the requirement of the improvement of etching rate, the power loaded by the lower radio frequency system is larger and larger, the power is larger, the delta V is larger, when the influence of the lower radio frequency system on electrostatic force reaches a non-negligible level, the adsorption force of the positive electrode and the negative electrode on the wafer is unbalanced, and even the situation that the negative electrode is not adsorbed is caused. The electrode adsorption force is unbalanced, the adsorption force is weak, the negative electrode side area with weak adsorption is not firm, back-blowing gas can leak, the leak rate is unqualified, and the process flow fails.
Referring to fig. 2, a schematic block diagram of an embodiment of an electrostatic chuck power supply for powering a chucking electrode of an electrostatic chuck of the semiconductor processing apparatus is shown.
In the embodiment of the invention, an electrostatic chuck power supply is connected with an electrostatic chuck of semiconductor process equipment to supply power for an electrostatic chuck adsorption electrode. For the electrostatic chuck power supply to be applied in the electrostatic chuck system, referring to fig. 3, a direct current self-bias voltage detection circuit is arranged in the matcher 14 in the lower radio frequency system, the voltage on the output terminal electrode of the matcher 14 is coupled to a circuit board through a high-voltage resistor, a bias voltage value- Δv is obtained after data processing, and the bias voltage value- Δv is converted into a 0-10V analog quantity signal V (≡Δv) and is transmitted to the user control system 30. The electrostatic chuck power supply 6 controls the port 31, receives instructions from the user control system 30, and performs corresponding bias voltage adjustment. The electrostatic chuck power supply 6 outputs direct current to the electrostatic chuck 7. The direct current self-bias voltage detection circuit is arranged in the radio frequency matcher of the semiconductor process equipment and is used for detecting the voltage value on the electrode at the output end of the radio frequency matcher to obtain a detection value of direct current self-bias voltage
The electrostatic chuck power supply may specifically include:
a control voltage generation circuit 100 for generating a control voltage according to a user setting value;
a boost circuit 200 for boosting the control voltage to obtain a high voltage;
a reference voltage introducing circuit 300 for providing a dc self-bias voltage, which is a voltage difference between a plasma sheath layer generated when the semiconductor processing apparatus performs a process and a wafer on the electrostatic chuck;
a positive voltage generating circuit 400, configured to superimpose the high voltage and the dc self-bias voltage to generate a positive voltage;
the negative voltage generating circuit 500 is configured to invert the high voltage and superimpose the high voltage with the dc self-bias voltage to generate a negative voltage.
In the embodiment of the invention, when the semiconductor process equipment executes the process, a voltage difference is generated between the plasma sheath layer of the semiconductor process equipment and the electrostatic chuck due to the influence of the high-frequency magnetic field, and the voltage difference is the direct-current self-bias voltage. The reference voltage introduction circuit 300 is used to supply a direct-current self-bias voltage to the positive voltage generation circuit 400 and the negative voltage generation circuit 500.
The control voltage generating circuit 100 may receive a control instruction sent by a user through a control system, where the control instruction includes a user setting value; generating a control voltage according to the user setting value; the booster circuit 200 is connected to an output terminal of the control voltage generation circuit 100, and boosts the control voltage to obtain a high voltage.
The positive electrode voltage generating circuit 400 is connected with the booster circuit 200 and the reference voltage introducing circuit 300, and superimposes the high-voltage and the direct-current self-bias voltage to generate a positive electrode voltage; and outputs a positive voltage to the electrostatic chuck.
The negative electrode voltage generating circuit 500 is connected to the voltage boosting circuit 200 and the reference voltage introducing circuit 300, and is configured to invert the high voltage and superimpose the high voltage on the dc self-bias voltage to generate a negative electrode voltage, and output the negative electrode voltage to the electrostatic chuck.
The absolute value of the positive electrode voltage relative to the direct current self-bias voltage is equal to the absolute value of the negative electrode voltage relative to the direct current self-bias voltage.
I.e. positive voltage output port HV of electrostatic chuck power supply + And negative voltage output port HV of electrostatic chuck power supply - Is set to be a DC self-bias voltage, regardless of DC self-biasThe voltage value of the bias voltage is HV + And HV (high voltage) - The absolute values of the voltages relative to the direct current self-bias voltage are always equal. The electrostatic chuck power supply carries out bias voltage adjustment in real time according to the direct current self-bias voltage, when the direct current self-bias voltage is minus delta V, the CT voltage value is minus delta V, the positive electrode loading voltage is changed from HV to (HV-delta V), the negative electrode loading voltage is changed from minus HV to minus HV-delta V, +U= (HV-delta V) +delta V1+delta V, -U '= (-HV-delta V) -delta V1+delta V, and thus the absolute value of the voltage difference between the positive electrode and the wafer is still (HV+delta V1), and U=U' is realized.
For example, set electrostatic chuck supply voltage output hv=2 kV (kilovolts), then HV + And HV (high voltage) - The pressure difference is 2kV, namely HV + -HV - =2 kV, at the same time |hv + -CT|＝|HV - -ct|=1 kV. When no DC self-bias exists, the CT voltage value is 0, HV + ＝1kV，HV - -1kV; the DC self-bias voltage is-0.5 kV, the voltage value of CT is-0.5 kV, HV + ＝0.5kV，HV - ＝-1.5kV。
According to the embodiment of the invention, the control voltage is generated by the control voltage generation circuit according to the user setting value; the boosting circuit boosts the control voltage to obtain a high-voltage; the reference voltage introducing circuit provides a direct current self-bias voltage, wherein the direct current self-bias voltage is a voltage difference between a plasma sheath layer and a wafer on the electrostatic chuck, which is generated when the semiconductor process equipment executes a process; the positive electrode voltage generating circuit is used for superposing the high-voltage and the direct-current self-bias voltage to generate a positive electrode voltage; the negative voltage generating circuit inverts the high voltage and superimposes the high voltage with the direct current self-bias voltage to generate a negative voltage. The positive electrode voltage and the negative electrode voltage are generated based on the direct current self-bias voltage, so that the influence of the voltage bias on the adsorption force of the electrostatic chuck is automatically compensated, the aim of balancing the adsorption force of the positive electrode and the negative electrode is achieved, and the adsorption failure phenomenon is prevented.
Referring to fig. 4, a circuit diagram of one embodiment of an electrostatic chuck power supply of the present invention is shown. The electrostatic chuck power supply includes: the control voltage generation circuit 100, the booster circuit 200, the reference voltage introduction circuit 300, the positive electrode voltage generation circuit 400, and the negative electrode voltage generation circuit 500.
Wherein the high voltage generation circuit 200 includes: the booster circuit includes a first transformer 210, a primary side of the first transformer 210 is connected to the control voltage generating circuit 100, and a secondary side of the first transformer 210 is connected to the positive voltage generating circuit 400 and the negative voltage 500 generating circuit.
In the embodiment of the present invention, the booster circuit includes a first voltage transformer 210, and the first transformer 210 may be a multi-turn coil forming a primary side of the first transformer 210 or a secondary side of the first transformer 210. The primary side of the first transformer 210 is connected with the control voltage generation circuit 100 and is connected with a control voltage; the secondary side of the first transformer 210 is connected to the positive electrode voltage generating circuit 400 and the negative electrode voltage 500 generating circuit, and outputs a high voltage to the positive electrode voltage generating circuit 400 and the negative electrode voltage 500. The first tap 4 of the first transformer main side 210 corresponds to the third tap 5 of the first transformer main side 210, and the second tap 1 of the main side 210 corresponds to the fourth tap 3 of the first transformer main side 210.
The control voltage generation circuit 100 includes a first square wave voltage generation circuit 110, and the first square wave voltage generation circuit 110 generates a first square wave voltage signal according to a user setting value, and the first square wave voltage signal is input to the primary side of the first transformer 210.
Specifically, the first square-wave voltage generation circuit 110 includes:
a first pulse width modulation circuit 111 that can generate a first pulse width modulation signal according to a user setting value;
the first PWM circuit 111 may use a dedicated PWM (Pulse width modulation ) generating chip, and according to a user setting value (HV), a first starting voltage value of the first PWM circuit 111 is given to control the first PWM circuit 24 to output PWM square waves 24 with different duty ratios, the PWM square waves 24 control the first control switch 112 to be turned on and off, the 24V dc is converted into a square wave, and then the square wave is boosted by the first transformer 210 in a certain proportion, and finally the secondary side of the transformer is the square wave 23 with the amplitude u. The positive electrode voltage generating circuit 400 converts the square wave 23 into positive electricity HV, and the negative electrode voltage generating circuit 500 converts the square wave 23 into negative electricity HV, i.e., the positive electrode voltage generating circuit 400 and the negative electrode voltage generating circuit 500 can output two paths simultaneously, positive electricity and negative electricity, to the electrostatic chuck.
The first control switch 112 is connected to the first pwm circuit 111, and the first control switch 112 may be a field effect transistor, a triode, etc., as shown in fig. 2. The control terminal (for example, the gate of the field effect transistor) of the first control switch 112 is connected to the first pulse width modulation circuit 111, the first terminal (for example, the drain of the field effect transistor) of the first control switch 112 is connected to the first tap 4 of the primary side of the first transformer 210 and the second tap 5 of the primary side 210 of the first transformer, the second terminal of the first control switch is grounded, and the switch state is switched under the triggering of the first pulse width modulation signal, so that the voltage of the primary side 210 of the first transformer can be controlled, and the second terminal (for example, the source of the field effect transistor) of the first control switch 112 is grounded.
One end of the first resistor R1 is connected with a preset power supply, a third tap 1 on the main side of the first transformer 210 and a fourth tap 2 on the main side of the first transformer 210. The first capacitor C1 is connected with the first resistor R1 in parallel; the cathode of the first diode D1 is connected with the other end of the first resistor R1, one end of the first capacitor C1 is connected, and the anode of the second diode D2 is connected with the output end of the first control switch 112.
The positive electrode voltage generating circuit 400 is connected to the high voltage circuit 200 and the reference voltage introducing circuit 300, and is configured to superimpose the high voltage and the dc self-bias voltage to generate a positive electrode voltage. Specifically, the positive electrode voltage generation circuit 400 includes: the second capacitor C2, the second diode D2, the third diode D3, the third capacitor C3 and the second resistor R2.
The second capacitor C2 is connected with the first tap 21 on the secondary side of the first transformer 210; the cathode of the second diode D2 is connected with the anode of the second capacitor C2; the anode of the third diode D3 is connected with the anode of the second capacitor C2 and the cathode of the second diode D2; the cathode of the third capacitor C3 is connected with the anode of the second diode D2, and the anode of the third capacitor C3 is connected with the reference voltage introducing circuit 300; one end of the second resistor R2 is connected with the cathode of the third diode D3, and the other end of the second resistor R2 is connected with the cathode of the third capacitor C3, the anode of the second diode D2 and the second tap 22 of the secondary side of the first transformer 210.
The negative electrode voltage generating circuit 500 is connected to the high voltage circuit 200 and the reference voltage introducing circuit 300, and is configured to invert the high voltage and superimpose the high voltage on the dc self-bias voltage to generate a negative electrode voltage. Specifically, the negative electrode voltage generation circuit includes: a fourth capacitor C4, a fourth diode D4, a fifth diode D5, a fifth capacitor C5, and a third resistor R3.
The anode of the fourth capacitor C4 is connected with the first tap 21 on the secondary side of the first transformer 210; the anode of the fourth diode D4 is connected with the cathode of the fourth capacitor C4; the cathode of the fifth diode D5 is connected with the cathode of the fourth capacitor C4 and the anode of the fourth diode D4; the positive electrode of the fifth capacitor C5 is connected with the negative electrode of the fourth diode D4, and the negative electrode of the fifth capacitor C5 is connected with the reference voltage introducing circuit 300 and the positive electrode of the fifth diode D5; one end of the third resistor R3 is connected with the positive electrode of the fifth diode D5 and the reference voltage introducing circuit 300, and the other end of the third resistor R3 is connected with the positive electrode of the fifth capacitor C5, the negative electrode of the fourth diode D4 and the second tap 22 of the secondary side of the first transformer 210.
The reference voltage introducing circuit 300 transmits the detected direct current self-bias voltage-DeltaV to the user control system when the current radio frequency system detects the direct current self-bias voltage-DeltaV, and generates corresponding user instructions, wherein the user instructions comprise monitoring values; the second square wave voltage generating circuit 310 determines a starting voltage value according to a user setting value to control the starting voltage value to output PWM square waves with different duty ratios, the PWM square waves control the second control switch 322 to be turned on and off, 24V direct current is converted into square waves, the square waves pass through the second transformer 320 to be boosted in a certain proportion, and finally the secondary side of the second transformer 320 is the square wave with the amplitude of u. The reference voltage output circuit shapes the square wave to generate a direct current self-bias voltage.
Specifically, the reference voltage introduction circuit 300 includes: a second square wave voltage generating circuit 310, a second transformer 320, and a reference voltage output circuit 330.
The second square wave voltage generating circuit 310 generates a second square wave voltage signal according to the detection value of the direct current self-bias voltage detecting circuit; the second square voltage generating circuit 310 on the main side of the second transformer 320 is connected to receive the second pulse width modulation signal to generate a direct current to be converted into a square wave; the reference voltage output circuit 330 is connected to the secondary side of the second transformer 320, and generates a dc self-bias voltage.
Further, referring to fig. 4, the second square wave voltage generating circuit 310 includes: the second pulse width modulation circuit 311, the second control switch 312, the fourth resistor R4, the sixth capacitor C6, and the sixth diode D6.
The second pulse width modulation circuit 311 generates a second pulse width modulation signal according to the detection value; the control end of the second control switch 312 is connected with the second pulse width modulation circuit 311, the first end of the second control switch 312 is connected with the first tap 4 on the main side of the second transformer 320 and the second tap 5 on the main side of the second transformer 320, the switch state is switched under the triggering of the second pulse width modulation signal, and the second end of the second control switch 312 is grounded; one end of the fourth resistor R4 is connected with a preset power supply, a third tap 1 on the main side of the second transformer 320 and a fourth tap 2 on the main side of the second transformer 320; the sixth capacitor C6 and the fourth resistor R4 are connected in parallel; the cathode of the sixth diode D6 is connected to the other end of the fourth resistor R4, one end of the sixth capacitor C6 is connected, and the anode of the sixth diode D6 is connected to the output end of the second control switch 310.
Further, the reference voltage output circuit includes: a seventh capacitor C7, a seventh diode D7, an eighth capacitor C8, an eighth diode D8, and a fifth resistor R5.
One end of the seventh capacitor C7 is connected with the first tap 10 of the secondary side of the second transformer 312; the positive electrode of the seventh diode D7 is connected with the other end of the seventh capacitor C7; one end of the eighth capacitor C8 is connected with the cathode of the seventh diode D7; the positive electrode of the eighth diode D8 is connected with the other end of the eighth capacitor C8, the positive electrode voltage generating circuit 400 and the negative electrode voltage generating circuit 500, and the negative electrode of the eighth diode D8 is connected with the positive electrode of the seventh diode D7 and one end of the seventh capacitor C7; one end of the fifth resistor R5 is connected to the anode of the eighth diode D8, the other end of the eighth capacitor C8, the anode voltage generating circuit 400, and the cathode voltage generating circuit 500, and the other end of the fifth resistor R5 is connected to the cathode of the seventh diode D7, one end of the eighth capacitor C8, and the second tap 6 of the secondary side of the second transformer 312.
According to the embodiment of the invention, the direct-current self-bias voltage is generated, the positive electrode voltage and the negative electrode voltage are generated based on the direct-current self-bias voltage, the influence of the voltage bias on the adsorption force of the electrostatic chuck is automatically compensated, the purpose of balancing the adsorption force of the positive electrode and the negative electrode is achieved, and the adsorption failure phenomenon is prevented.
Referring to fig. 5, the embodiment of the invention further discloses an electrostatic chuck power supply, which is applied to semiconductor process equipment, and is used for supplying power to an adsorption electrode of an electrostatic chuck of the semiconductor process equipment, and the electrostatic chuck power supply comprises:
a forward control voltage generating circuit 600, configured to generate a forward control voltage according to a sum of a user setting value and a detection value of a dc self-bias voltage detecting circuit, where the dc self-bias voltage is a voltage difference between a plasma sheath layer generated when the semiconductor processing apparatus performs a process and a wafer on the electrostatic chuck;
a reverse control voltage generation circuit 700 for generating a reverse control voltage according to a sum of a negative value of a user setting value and a detection value of the direct current self-bias voltage detection circuit;
a first boost circuit 800 for boosting the forward control voltage to obtain a positive voltage;
and the second boost circuit 900 is configured to boost the reverse control voltage to obtain a negative voltage.
In the embodiment of the invention, the direct current self-bias voltage is the voltage difference between the plasma sheath layer and the wafer on the electrostatic chuck, which is generated when the semiconductor process equipment executes the process; the dc self-bias voltage may be a predetermined value, such as zero when grounded. The positive electrode voltage and the negative electrode voltage may be generated in the electrostatic chuck power supply based on a detection value set by a user and a direct current self-bias detection circuit. The forward control voltage generating circuit 600 generates a forward control voltage according to a sum of a user setting value and a detection value of the direct current self-bias voltage detecting circuit, the first voltage boosting circuit 800 is connected with the forward control voltage generating circuit 600, the first voltage boosting circuit 800 boosts the forward control voltage to obtain a positive electrode voltage, and the positive electrode voltage is supplied to a positive electrode in the adsorption electrode of the electrostatic chuck. The reverse control voltage generating circuit 700 generates a reverse control voltage according to the sum of the negative value of the user setting value and the detection value of the direct current self-bias voltage detecting circuit, the second voltage boosting circuit 900 is connected with the reverse control voltage generating circuit 700, and the second voltage boosting circuit 900 boosts the reverse control voltage to obtain a negative voltage. The negative electrode voltage is delivered to a negative electrode in the chucking electrode of the electrostatic chuck.
In particular, reference may be made to fig. 6. The first booster circuit 800 includes: the third transformer 810, the ninth capacitor C9, the ninth diode D9, the tenth diode D10, the tenth capacitor C10, and the sixth resistor R6.
The main side of the third transformer 810 is connected with the forward control voltage generation circuit 600; the negative electrode of the ninth capacitor C9 is connected with the first tap 21 on the secondary side of the third transformer 810; the cathode of the ninth diode D9 is connected with the anode of the ninth capacitor C9; the positive electrode of the twelfth electrode tube D10 is connected with the positive electrode of the ninth capacitor C9 and the negative electrode of the ninth diode D9; one end of a tenth capacitor C10 is connected with the positive electrode of a ninth diode D9, and the positive electrode of the tenth capacitor C10 is grounded to GND; one end of a sixth resistor R6 is connected with the negative electrode of the twelfth electrode tube D10, the other end of the ninth resistor R9 is connected with the other end of the tenth capacitor C10, the positive electrode of the ninth diode D9 and the second tap 22 of the secondary side of the third transformer 810, and the second tap of the secondary side of the third transformer 810 is grounded.
The second booster circuit 900 includes: a fourth transformer 910, an eleventh capacitor C11, an eleventh diode D11, a twelfth diode D12, a twelfth capacitor C12, and a seventh resistor R7.
The main side of the fourth transformer 910 is connected to the reverse control voltage generating circuit 700; the anode of the eleventh capacitor C11 is connected with the first tap 21 on the secondary side of the fourth transformer 910; the anode of the eleventh diode D11 is connected with the cathode of the eleventh capacitor C11; the cathode of the twelfth diode D12 is connected with the cathode of the eleventh capacitor C11 and the anode of the eleventh diode D11; the positive electrode of the twelfth capacitor C12 is connected with the negative electrode of the twelfth diode D12, and one end of the twelfth capacitor C12 is connected with the positive electrode of the twelfth diode D12 and the preset ground GND; one end of a seventh resistor R7 is connected with the positive electrode of a twelfth diode D12 and a preset ground GND, the other end of the seventh resistor R7 is connected with the other end of a twelfth capacitor C12, the negative electrode of an eleventh diode D11 and a second tap 22 on the secondary side of the fourth transformer 910, and the second tap on the secondary side of the fourth transformer 910 is grounded.
The forward control voltage generation circuit 600 specifically includes: and a third-party-wave voltage generating circuit 610, wherein the third-party-wave voltage generating circuit 610 generates a third-party-wave voltage signal with a preset duty ratio according to the sum of the user setting value and the detection value of the direct current self-bias voltage detecting circuit, and inputs the third-party-wave voltage signal to the main side of the third transformer 810.
The third-party-voltage generating circuit 610 specifically includes: a third pulse width modulation circuit 611, a third control switch 612, an eighth resistor R8, a thirteenth capacitor C13, and a thirteenth diode D13.
The third pulse width modulation circuit 611 generates a third pulse width modulation signal according to the sum of the user setting value and the detection value of the direct current self-bias detection circuit; the control end of the third control switch 612 is connected with the third pulse width modulation circuit 311, the first end of the third control switch 312 is connected with the first tap 5 on the main side of the third transformer 810 and the second tap 4 on the main side of the third transformer 810, the switch state is switched under the triggering of the third pulse width modulation signal, and the second end of the third control switch 312 is grounded; the third control switch 611 may be a field effect transistor, a triode, or the like. The field effect transistor is used in the example of the invention. One end of the eighth resistor R8 is connected with a preset power supply, a third tap 1 on the main side of the third transformer 810 and a fourth tap 2 on the main side of the third transformer 810; the thirteenth capacitor C13 is connected with the eighth resistor R8 in parallel; the negative electrode of the thirteenth diode D13 is connected with the other end of the eighth resistor R8, one end of the thirteenth capacitor D13 is connected, the positive electrode of the thirteenth diode D13 is connected with the output end of the third control switch 611, the first tap of the main side of the third transformer 810 corresponds to the third tap of the main side of the third transformer 810, and the second tap of the main side of the third transformer 810 corresponds to the fourth tap of the main side of the third transformer 810.
The reverse control voltage generation circuit 700 specifically includes: and a fourth square wave voltage generating circuit 710, the fourth square wave voltage generating circuit 710 generating a fourth square wave voltage signal of a preset duty ratio according to a sum of a negative value of a user setting value and a detection value of the direct current self-bias voltage detecting circuit, and inputting the fourth square wave voltage signal to a main side of the fourth transformer 910.
Specifically, the fourth-wave voltage generation circuit 710 includes: a fourth pulse width modulation circuit 711, a fourth control switch 712, a ninth resistor R9, a fourteenth capacitor C14, and a fourteenth diode D14.
The fourth pulse width modulation circuit 711 generates a fourth pulse width modulation signal according to a sum of a negative value of the user setting value and a detection value of the direct current self-bias detection circuit and a sum of a detection value of the direct current self-bias detection circuit; the control end of the fourth control switch 712 is connected to the fourth pulse width modulation circuit 711, the first end of the fourth control switch 712 is connected to the first tap 5 on the main side of the fourth transformer 910 and the second tap 4 on the main side of the third transformer 910, the switch state is switched under the triggering of the fourth pulse width modulation signal, and the second end of the fourth control switch 712 is grounded; one end of the ninth resistor R9 is connected with a preset power supply, a third tap 1 on the main side of the fourth transformer 910 and a fourth tap 2 on the main side of the fourth transformer 910; the fourteenth capacitor C14 is connected with the ninth resistor R9 in parallel; the negative electrode of the fourteenth diode D14 is connected to the other end of the ninth resistor R9, one end of the fourteenth capacitor C14 is connected, and the positive electrode of the fourteenth diode D14 is connected to the output end of the fourth control switch 712.
Referring to fig. 7, the embodiment of the present invention further discloses a semiconductor process apparatus, which includes a radio frequency power supply 710, a radio frequency matcher 720, and a process chamber 730, wherein the process chamber 730 includes an electrostatic chuck and the electrostatic chuck power supply described above;
the electrostatic chuck power supply is used for generating positive voltage and negative voltage to the adsorption electrode of the electrostatic chuck so as to carry out electrostatic adsorption on the wafer on the electrostatic chuck;
the rf power supply 710 is configured to load rf power to the electrostatic chuck through the rf matcher 720 to generate a plasma sheath on the upper surface of the wafer on the electrostatic chuck.
In an optional embodiment of the present invention, the rf matcher includes a dc self-bias voltage detection circuit, where the dc self-bias voltage detection circuit is configured to detect a voltage value on an output electrode of the rf matcher to obtain a detected value of a dc self-bias voltage;
the electrostatic chuck power supply is configured to generate a positive voltage and a negative voltage to a chucking electrode of the electrostatic chuck based on the detection value and a user setting value.
In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described by differences from other embodiments, and identical and similar parts between the embodiments are all enough to be referred to each other.
It will be apparent to those skilled in the art that embodiments of the present invention may be provided as a method, apparatus, or computer program product. Accordingly, embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, embodiments of the invention may take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) having computer-usable program code embodied therein.
Embodiments of the present invention are described with reference to flowchart illustrations and/or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
While preferred embodiments of the present invention have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiment and all such alterations and modifications as fall within the scope of the embodiments of the invention.
Finally, it is further noted that relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or terminal device comprising the element.
The foregoing has described in detail an electrostatic chuck power supply, a process chamber and semiconductor processing equipment provided by the present invention, and specific examples have been provided herein to illustrate the principles and embodiments of the present invention, the above examples being provided only to assist in understanding the method of the present invention and its core ideas; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in accordance with the ideas of the present invention, the present description should not be construed as limiting the present invention in view of the above.

Claims (15)

1. An electrostatic chuck power supply for use with semiconductor processing equipment, the electrostatic chuck power supply for powering a chucking electrode of an electrostatic chuck of the semiconductor processing equipment, the electrostatic chuck power supply comprising:
a control voltage generation circuit for generating a control voltage according to a user setting value;
the boost circuit is used for boosting the control voltage to obtain a high-voltage;
the reference voltage introducing circuit is used for providing direct current self-bias voltage which is the voltage difference between the plasma sheath layer and the wafer on the electrostatic chuck, wherein the voltage difference is generated when the semiconductor process equipment executes the process;
the positive voltage generating circuit is used for superposing the high-voltage and the direct-current self-bias voltage to generate a positive voltage;
and the negative voltage generating circuit is used for reversing the high-voltage and superposing the high-voltage and the direct-current self-bias voltage to generate a negative voltage.
2. The electrostatic chuck power supply of claim 1, wherein the boost circuit comprises a first transformer, the primary side of the first transformer being connected to the control voltage generation circuit, the secondary side of the first transformer being connected to the positive voltage generation circuit and the negative voltage generation circuit.
3. The electrostatic chuck power supply of claim 2, wherein the control voltage generation circuit comprises:
and the first square wave voltage generation circuit is used for generating a first square wave voltage signal according to the user setting value, and the first square wave voltage signal is input to the primary side of the first transformer.
4. The electrostatic chuck power supply of claim 3, wherein the first square wave voltage generation circuit comprises:
the first pulse width modulation circuit is used for generating a first pulse width modulation signal according to a user setting value;
the control end of the first control switch is connected with the first pulse width modulation circuit, the first end of the first control switch is connected with a first tap of the primary side of the first transformer and a second tap of the primary side of the first transformer, the state of the switch is switched under the triggering of the first pulse width modulation signal, and the second end of the first control switch is grounded;
one end of the first resistor is connected with a preset power supply, a third tap of the primary side of the first transformer and a fourth tap of the primary side of the first transformer, the first tap of the primary side of the first transformer corresponds to the third tap of the primary side of the first transformer, and the second tap of the primary side of the first transformer corresponds to the fourth tap of the primary side of the first transformer;
A first capacitor connected in parallel with the first resistor;
and the cathode of the first diode is connected with the other end of the first resistor, and the anode of the second diode is connected with the first end of the first control switch.
5. The electrostatic chuck power supply of claim 2, wherein the positive voltage generation circuit comprises:
one end of the second capacitor is connected with a first tap of the secondary side of the first transformer;
the cathode of the second diode is connected with the other end of the second capacitor;
the anode of the third diode is connected with the other end of the second capacitor and the cathode of the second diode;
one end of the third capacitor is connected with the anode of the second diode, the second tap of the secondary side of the first transformer and the reference voltage introducing circuit, and the other end of the third capacitor is connected with the anode of the second diode and serves as the output end of the anode voltage generating circuit to output the anode voltage;
the second resistor is connected with the third capacitor in parallel; and/or
The negative electrode voltage generation circuit includes:
the positive electrode of the fourth capacitor is connected with the first tap of the secondary side of the first transformer;
The anode of the fourth diode is connected with the cathode of the fourth capacitor;
the cathode of the fifth diode is connected with the cathode of the fourth capacitor and the anode of the fourth diode;
one end of the fifth capacitor is connected with the cathode of the fourth diode and the reference voltage introducing circuit, and the other end of the fifth capacitor is connected with the anode of the fifth diode and is used as an output end of the cathode voltage generating circuit to output the cathode voltage;
and one end of the third resistor is connected with the positive electrode of the fifth diode and the reference voltage introducing circuit, and the other end of the third resistor is connected with the positive electrode of the fifth capacitor, the negative electrode of the fourth diode and the second tap of the secondary side of the first transformer.
6. The electrostatic chuck power supply of any one of claims 1-5, wherein the reference voltage introduction circuit comprises:
the second square wave voltage generating circuit is used for generating a second square wave voltage signal according to the detection value of the direct current self-bias voltage detection circuit;
the main side of the second transformer is connected with the second square wave voltage generating circuit;
and the reference voltage output circuit is connected with the secondary side of the second transformer to generate the direct current self-bias voltage.
7. The electrostatic chuck power supply of claim 6, wherein the second square wave voltage generation circuit comprises:
the second pulse width modulation circuit is used for generating a second pulse width modulation signal according to the detection value;
the control end of the second control switch is connected with the second pulse width modulation circuit, the first end of the second control switch is connected with the first tap of the main side of the second transformer and the second tap of the main side of the second transformer, the state of the switch is switched under the triggering of the second pulse width modulation signal, and the second end of the second control switch is grounded;
one end of the fourth resistor is connected with a preset power supply, a third tap of the main side of the second transformer and a fourth tap of the main side of the second transformer; the first tap of the main side of the second transformer corresponds to the third tap of the main side of the second transformer, and the second tap of the main side of the second transformer corresponds to the fourth tap of the main side of the second transformer;
a sixth capacitor connected in parallel with the fourth resistor;
the negative electrode of the sixth diode is connected with the other end of the fourth resistor, and the positive electrode of the sixth diode is connected with the first end of the second control switch; or;
The reference voltage output circuit includes:
one end of the seventh capacitor is connected with the first tap of the secondary side of the second transformer;
the anode of the seventh diode is connected with the other end of the seventh capacitor;
one end of the eighth capacitor is connected with the cathode of the seventh diode;
an eighth diode, wherein the anode of the eighth diode is connected with the other end of the eighth capacitor, the positive voltage generating circuit and the negative voltage generating circuit, and the cathode of the eighth diode is connected with the anode of the seventh diode and the other end of the seventh capacitor;
and one end of the fifth resistor is connected with the anode of the eighth diode, the other end of the eighth capacitor, the anode voltage generating circuit and the cathode voltage generating circuit, and the other end of the fifth resistor is connected with the cathode of the seventh diode, one end of the eighth capacitor and the secondary side second tap of the second transformer.
8. The electrostatic chuck power supply of claim 6, wherein the dc self-bias voltage detection circuit is disposed in a radio frequency matcher of the semiconductor processing apparatus, and is configured to detect a voltage value on an output electrode of the radio frequency matcher to obtain a detected value of the dc self-bias voltage.
9. An electrostatic chuck power supply for use with semiconductor processing equipment, the electrostatic chuck power supply for powering a chucking electrode of an electrostatic chuck of the semiconductor processing equipment, the electrostatic chuck power supply comprising:
the forward control voltage generation circuit is used for generating a forward control voltage according to the sum of a user set value and a detection value of the direct current self-bias voltage detection circuit, wherein the direct current self-bias voltage is a voltage difference between a plasma sheath layer and a wafer on the electrostatic chuck, which is generated when the semiconductor process equipment executes a process;
a reverse control voltage generation circuit for generating a reverse control voltage according to a sum of a negative value of a user setting value and a detection value of the direct current self-bias voltage detection circuit;
the first boosting circuit is used for boosting the forward control voltage to obtain positive voltage;
and the second boosting circuit is used for boosting the reverse control voltage to obtain a negative electrode voltage.
10. The electrostatic chuck power supply of claim 9, wherein the first boost circuit comprises:
the main side of the third transformer is connected with the forward control voltage generation circuit;
The negative electrode of the ninth capacitor is connected with the first tap of the secondary side of the third transformer;
a ninth diode, wherein the cathode of the ninth diode is connected with the anode of the ninth capacitor;
a twelfth diode, wherein the positive electrode of the tenth diode is connected with the positive electrode of the ninth capacitor and the negative electrode of the ninth diode;
a tenth capacitor, one end of which is connected with the positive electrode of the ninth diode, and the other end of which is used as the output end of the first boost circuit to output the positive electrode voltage;
one end of the sixth resistor is connected with the negative electrode of the twelfth electrode tube, the other end of the ninth resistor is connected with the negative electrode of the tenth capacitor, the positive electrode of the ninth diode and the second tap of the secondary side of the third transformer, and the second tap of the secondary side of the third transformer is grounded; or;
the second booster circuit includes:
a fourth transformer, the main side of which is connected with the reverse control voltage generating circuit,
the positive electrode of the eleventh capacitor is connected with the first tap of the secondary side of the fourth transformer;
an eleventh diode, wherein the anode of the eleventh diode is connected with the cathode of the eleventh capacitor;
A twelfth diode, wherein the negative electrode of the twelfth diode is connected with the negative electrode of the eleventh capacitor and the positive electrode of the eleventh diode;
a twelfth capacitor, one end of which is connected with the cathode of the twelfth diode, and the other end of which is connected with the anode of the twelfth diode and is used as the output end of the second booster circuit generating circuit to output the cathode voltage;
and one end of the seventh resistor is connected with the anode of the twelfth diode in a preset manner, the other end of the seventh resistor is connected with the anode of the twelfth capacitor, the cathode of the eleventh diode and the second tap of the secondary side of the fourth transformer, and the second tap of the secondary side of the fourth transformer is grounded.
11. The electrostatic chuck power supply of claim 9, wherein the forward control voltage generation circuit comprises:
the third-party-wave voltage generating circuit is used for generating a third-party-wave voltage signal with a preset duty ratio according to the sum of a user setting value and a detection value of the direct-current self-bias voltage detecting circuit, and inputting the third-party-wave voltage signal to the main side of the third transformer; or (b)
The reverse control voltage generation circuit includes:
And the fourth wave voltage generating circuit is used for generating a fourth wave voltage signal with a preset duty ratio according to the sum of the negative value of the user setting value and the detection value of the direct current self-bias voltage detection circuit, and inputting the fourth wave voltage signal to the main side of the fourth transformer.
12. The electrostatic chuck power supply of claim 11, wherein the third ripple voltage generation circuit comprises:
the third pulse width modulation circuit is used for generating a third pulse width modulation signal according to the sum of the user setting value and the detection value of the direct current self-bias voltage detection circuit;
the control end of the third control switch is connected with the third pulse width modulation circuit, the first end of the third control switch is connected with the first tap of the main side of the third transformer and the second tap of the main side of the third transformer, the state of the switch is switched under the triggering of the third pulse width modulation signal, and the second end of the third control switch is grounded;
one end of the eighth resistor is connected with the preset power supply, the third tap of the main side of the third transformer and the fourth tap of the main side of the third transformer, the first tap of the main side of the third transformer corresponds to the third tap of the main side of the third transformer, and the second tap of the main side of the third transformer corresponds to the fourth tap of the main side of the third transformer;
A thirteenth capacitor connected in parallel with the eighth resistor;
a thirteenth diode, wherein the cathode of the thirteenth diode is connected with the other end of the eighth resistor, one end of the thirteenth capacitor is connected, and the anode of the thirteenth diode is connected with the first end of the third control switch; or;
the fourth-wave voltage generation circuit includes:
the fourth pulse width modulation circuit is used for generating a fourth pulse width modulation signal according to the sum of the negative value of the user setting value and the detection value of the direct current self-bias voltage detection circuit and the sum of the detection value of the direct current self-bias voltage detection circuit;
the control end of the fourth control switch is connected with the fourth pulse width modulation circuit, the output end of the fourth control switch is connected with a first tap of the main side of the fourth transformer and a second tap of the main side of the third transformer, the state of the switch is switched under the triggering of the fourth pulse width modulation signal, and the second end of the fourth control switch is grounded;
one end of the ninth resistor is connected with the preset power supply, the third tap of the main side of the fourth transformer and the fourth tap of the main side of the fourth transformer; the first tap of the main side of the fourth transformer corresponds to the third tap of the main side of the fourth transformer, and the second tap of the main side of the fourth transformer corresponds to the fourth tap of the main side of the fourth transformer;
A fourteenth capacitor connected in parallel with the ninth resistor;
and the negative electrode of the fourteenth diode is connected with the other end of the ninth resistor, one end of the fourteenth capacitor is connected, and the positive electrode of the fourteenth diode is connected with the first end of the fourth control switch.
13. The electrostatic chuck power supply of any one of claims 9-12, wherein the dc self-bias voltage detection circuit is disposed in a rf matcher of the semiconductor processing apparatus, and is configured to detect a voltage value on an output electrode of the rf matcher to obtain a detected value of the dc self-bias voltage.
14. A semiconductor process apparatus comprising a radio frequency power supply, a radio frequency matcher, and a process chamber comprising an electrostatic chuck and the electrostatic chuck power supply of any one of claims 1 to 8 or any one of claims 9 to 13;
the electrostatic chuck power supply is used for generating positive voltage and negative voltage to the adsorption electrode of the electrostatic chuck so as to carry out electrostatic adsorption on the wafer on the electrostatic chuck;
the radio frequency power supply is used for loading radio frequency power to the electrostatic chuck through the radio frequency matcher so as to generate a plasma sheath layer on the upper surface of the wafer on the electrostatic chuck.
15. The semiconductor processing apparatus of claim 14, wherein the rf matcher includes a dc self-bias voltage detection circuit configured to detect a voltage value on an output electrode of the rf matcher to obtain a detected value of the dc self-bias voltage;
the electrostatic chuck power supply is configured to generate a positive voltage and a negative voltage to a chucking electrode of the electrostatic chuck based on the detection value and a user setting value.
CN202310298060.5A 2023-03-24 2023-03-24 Electrostatic chuck power supply and semiconductor processing apparatus Pending CN116436286A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310298060.5A CN116436286A (en) 2023-03-24 2023-03-24 Electrostatic chuck power supply and semiconductor processing apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310298060.5A CN116436286A (en) 2023-03-24 2023-03-24 Electrostatic chuck power supply and semiconductor processing apparatus

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CN116436286A true CN116436286A (en) 2023-07-14

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