Interlock circuit and semiconductor process equipment

Abstract

The invention provides an interlocking circuit and semiconductor process equipment, the interlocking circuit comprises a first control switch and a second control switch, the first control switch is used for cutting off a pressure release valve control signal output by an industrial personal computer when the electrostatic adsorption voltage of an electrostatic chuck is smaller than a preset voltage threshold, and the second control switch is used for cutting off a pressure release valve control signal output by an industrial personal computer when the electrostatic adsorption voltage of the electrostatic chuck is smaller than the preset voltage threshold; an air inlet valve control signal output by the industrial personal computer is communicated to the control end of the second control switch; the second control switch is used for outputting a closing signal to an air inlet valve of the back blowing pipeline and outputting an opening signal to a pressure release valve of the back blowing pipeline when the control end of the second control switch is communicated with the air inlet valve control signal. Local hardware interlocking is achieved through the interlocking circuit, damage caused by drifting or flying piece collision of the wafer can be avoided, and the safety of the semiconductor technology is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor process equipment, and specifically, to an interlock circuit for an electrostatic chuck back-blow pipeline and a semiconductor process equipment. Background Art

[0002] In semiconductor process equipment such as etching machines, an electrostatic chuck (ESC) is usually used to provide a supporting effect for the back surface of a wafer. Specifically, a DC electrode is embedded in the dielectric layer of the electrostatic chuck, and the DC electrode is connected to a high-voltage DC power supply to polarize the surface charges of the dielectric, thereby fixing the wafer by electrostatic adsorption. At the same time, helium gas at a certain pressure is introduced between the wafer and the electrostatic chuck to make the wafer obtain a more uniform dynamic constant temperature. At this time, it is necessary to ensure that the Coulomb force of electrostatic adsorption is greater than the helium gas pressure on the back surface of the wafer, otherwise the wafer will drift or fly off, causing damage.

[0003] However, existing semiconductor process equipment often cannot detect the abnormal electrostatic adsorption voltage in time. When the electrostatic chuck cannot effectively fix the wafer, helium gas is continuously introduced into the back surface of the wafer, resulting in the wafer drifting or flying off under the action of the helium gas pressure, and then causing wafer damage, with poor safety.

[0004] Therefore, how to provide a semiconductor process equipment that can detect the abnormal adsorption voltage of the wafer in time and ensure the safety of the semiconductor process has become an urgent technical problem in this field. Summary of the Invention

[0005] The present invention aims to provide an interlock circuit for an electrostatic chuck back-blow pipeline and a semiconductor process equipment, which can detect the abnormal adsorption voltage of the wafer in time and ensure the safety of the semiconductor process.

[0006] To achieve the above object, as one aspect of the present invention, an interlock circuit for an electrostatic chuck back-blow pipeline is provided, including a first control switch and a second control switch, wherein

[0007] The first control switch is configured to disconnect the pressure relief valve control signal output by the industrial control computer when the electrostatic adsorption voltage of the electrostatic chuck is less than a preset voltage threshold, and connect the intake valve control signal output by the industrial control computer to the control end of the second control switch;

[0008] The second control switch is configured to output a closing signal to the intake valve of the back-blow pipeline and an opening signal to the pressure relief valve of the back-blow pipeline when its control end is connected to the intake valve control signal.

[0009] Optionally, when the control terminal of the second control switch is connected to the intake valve control signal, if the intake valve control signal is open, the second control switch is triggered to output a high-impedance state signal to the intake valve and a high-level signal to the pressure relief valve; or

[0010] if the intake valve control signal is closed, the second control switch is not triggered, and high-impedance state signals are output to the intake valve and the pressure relief valve respectively.

[0011] Optionally, the first control switch is further configured to connect the intake valve control signal and the pressure relief valve control signal to the intake valve and the pressure relief valve respectively when the static adsorption voltage detected by the voltage sensor is greater than or equal to the preset voltage threshold.

[0012] Optionally, the intake valve control signal and the pressure relief valve control signal are connected to the intake valve and the pressure relief valve respectively via the second control switch.

[0013] Optionally, the first control switch is a double-pole double-throw relay. The first stationary terminal of the first control switch is electrically connected to the intake valve control signal output port of the industrial control computer, and the second stationary terminal of the first control switch is electrically connected to the pressure relief valve control signal output port of the industrial control computer;

[0014] The first normally open contact corresponding to the first stationary terminal is electrically connected to the control terminal of the second control switch, and the second normally open contact corresponding to the second stationary terminal is left floating;

[0015] The first normally closed contact corresponding to the first stationary terminal and the second normally closed contact corresponding to the second stationary terminal are respectively connected to the signal input terminals of the second control switch.

[0016] Optionally, the second control switch is a double-pole double-throw relay. The third stationary terminal of the second control switch is electrically connected to the intake valve, and the fourth stationary terminal of the second control switch is electrically connected to the pressure relief valve;

[0017] The third normally open contact corresponding to the third stationary terminal is left floating, and the fourth normally open contact corresponding to the fourth stationary terminal is connected to a high level;

[0018] The third normally closed contact corresponding to the third stationary terminal and the fourth normally closed contact corresponding to the fourth stationary terminal serve as the signal input terminals of the second control switch and are respectively electrically connected to the first normally closed contact and the second normally closed contact.

[0019] Optionally, the first end of the electromagnetic winding of the first control switch is connected to a high level, and the second end of the electromagnetic winding of the first control switch is grounded; the first end of the electromagnetic winding of the second control switch is connected to the first normally open contact corresponding to the first fixed end, and the second end of the electromagnetic winding of the second control switch is grounded.

[0020] Optionally, the interlock circuit further includes an input connector, an output connector, and a reference voltage connector. The first fixed end and the second fixed end are both connected to the input connector, and the third fixed end and the fourth fixed end are both connected to the output connector;

[0021] The second ends of the electromagnetic windings of the first control switch and the second control switch are both grounded through the reference voltage connector, and the first ends of the electromagnetic windings of the first control switch and the fourth normally open contact are both connected to a high level through the reference voltage connector.

[0022] As a second aspect of the present invention, there is provided a semiconductor processing apparatus, including a chamber, an electrostatic chuck, a back-blowing pipeline, a controller, a voltage sensor, and the interlock circuit described above. The electrostatic chuck is disposed in the chamber and is used to adsorb a wafer by electrostatic adsorption. The voltage sensor is used to detect the electrostatic adsorption voltage of the electrostatic chuck. An intake valve and a pressure relief valve are disposed on the back-blowing pipeline. The interlock circuit is used to output a switching signal to the intake valve and the pressure relief valve according to the electrostatic adsorption voltage of the electrostatic chuck detected by the voltage sensor.

[0023] In the semiconductor processing apparatus provided by the present invention, when the electrostatic adsorption force of the electrostatic chuck is sufficient to fix the wafer (i.e., when the electrostatic adsorption voltage is greater than or equal to a preset voltage threshold), the interlock circuit can normally transmit the control signal of the industrial control computer to the intake valve and the pressure relief valve to open or close the pressure relief valve. When the electrostatic adsorption force of the electrostatic chuck is too small (i.e., when the electrostatic adsorption voltage is less than the preset voltage threshold), the intake valve is controlled to close and the pressure relief valve is controlled to open, so as to realize local hardware interlock through the voltage sensor and the interlock circuit of the semiconductor processing apparatus. Even if the industrial control computer makes a misjudgment due to reasons such as a failure of the power supply component and issues an incorrect control signal, the back-blowing pipeline will not supply gas when the electrostatic adsorption force of the electrostatic chuck is too small, thereby avoiding damage to the wafer caused by drift or flying chip collision, and ensuring the safety of the semiconductor process and the product yield of the wafer.

[0024] Moreover, in the present invention, the interlock cut-off control is directly implemented by using the hardware of the interlock circuit, and the original control signal of the industrial control computer can be reused to achieve the necessary processes of stopping gas supply and pressure relief, avoiding the development cost of redesigning the relevant software process of the industrial control computer, and directly adding a device can realize the corresponding function, improving the adaptability of the semiconductor processing apparatus to different machines. Description of the Drawings

[0025] The accompanying drawings are used to provide a further understanding of the present invention and form a part of the specification. Together with the following detailed description, they are used to explain the present invention, but do not constitute a limitation to the present invention. In the accompanying drawings:

[0026] Figure 1 is a schematic structural diagram of a semiconductor process equipment provided by an embodiment of the present invention;

[0027] Figure 2 is a schematic structural diagram of an interlock circuit provided by an embodiment of the present invention;

[0028] Figure 3 is a schematic functional logic diagram of the interlock circuit provided by an embodiment of the present invention.

[0029] Description of reference numerals:

[0030] Chamber 110;

[0031] Electrostatic chuck 120;

[0032] Adsorption electrode 121;

[0033] Back-blow pipeline 210;

[0034] Intake valve 220;

[0035] Pressure relief valve 230;

[0036] Voltage sensor 300;

[0037] Interlock circuit 400;

[0038] First control switch 410;

[0039] Second control switch 420;

[0040] Controller 500;

[0041] Power supply assembly 600;

[0042] High-voltage DC power supply 610;

[0043] DC filter box 620;

[0044] Solenoid valve group 700;

[0045] Wafer 10. Detailed description of the specific implementation mode

[0046] The following provides a detailed description of the specific implementation mode of the present invention with reference to the accompanying drawings. It should be understood that the specific implementation mode described herein is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0047] To solve the above technical problems, the present invention provides an interlock circuit for the back-blow pipeline of an electrostatic chuck, which is applied to the back-blow pipeline of the electrostatic chuck of semiconductor process equipment, such as Figure 1 As shown, the semiconductor process equipment includes a cavity 110, an electrostatic chuck 120, and a back-blow pipeline. The electrostatic chuck 120 is disposed in the cavity 110 and is used to adsorb a wafer 10 through electrostatic adsorption based on the received electrostatic adsorption voltage. An intake valve 220 and a pressure relief valve 230 are provided on the back-blow pipeline 210. As Figure 2 As shown, the interlock circuit 400 includes a first control switch 410 and a second control switch 420, wherein

[0048] The first control switch 410 is configured to disconnect the pressure relief valve control signal output by the industrial control machine (controller 500) when the electrostatic adsorption voltage of the electrostatic chuck 120 is less than a preset voltage threshold, and connect the intake valve control signal output by the industrial control machine to the control end of the second control switch 420; wherein, the electrostatic adsorption voltage can be detected, for example, by a voltage sensor 300 electrically connected to the adsorption electrode 121 of the electrostatic chuck 120.

[0049] The second control switch 420 is configured to output a closing signal to the intake valve 220 of the back-blow pipeline and an opening signal to the pressure relief valve 230 of the back-blow pipeline when its control end is connected to the intake valve control signal.

[0050] In the interlock circuit provided by the present invention, the first control switch 410 can disconnect the pressure relief valve control signal output by the industrial control machine according to the pressure relief control signal issued by the industrial control machine when the electrostatic adsorption voltage is less than the preset voltage threshold, and connect the intake valve control signal output by the industrial control machine to the control end of the second control switch 420, and connect the intake valve control signal output by the industrial control machine to the control end of the second control switch 420; the second control switch 420 can output a closing signal to the intake valve 220 of the back-blow pipeline and an opening signal to the pressure relief valve 230 of the back-blow pipeline when its control end is connected to the intake valve control signal, so as to control the intake valve 220 to close and the pressure relief valve 230 to open when the electrostatic adsorption voltage is lower than the preset voltage threshold.

[0051] That is, when the electrostatic adsorption force of the electrostatic chuck 120 is sufficient to fix the wafer 10 (i.e., when the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold), the control signal of the industrial control computer will be normally transmitted to the intake valve 220 and the pressure relief valve 230 to open or close the pressure relief valve. When the electrostatic adsorption force of the electrostatic chuck 120 is too small (i.e., when the electrostatic adsorption voltage is less than the preset voltage threshold), the intake valve 220 is controlled to close and the pressure relief valve 230 is controlled to open, so as to realize local hardware interlock through the voltage sensor 300 and the interlock circuit 400 of the semiconductor process equipment. Even if the industrial control computer makes a misjudgment due to a failure of the power supply component 600 and issues an incorrect control signal, the backflush pipeline 210 will not supply gas when the electrostatic adsorption force of the electrostatic chuck 120 is too small, thus avoiding damage to the wafer 10 caused by drift or flying chip collision, and ensuring the safety of the semiconductor process and the product yield of the wafer 10.

[0052] Moreover, in the present invention, the interlock cut-off control is directly implemented by using the hardware of the interlock circuit 400, and the original control signal of the industrial control computer can be reused to achieve the necessary processes of stopping gas supply and relieving pressure, avoiding the development cost of redesigning the relevant software process of the industrial control computer. The corresponding function can be realized by directly adding the device, improving the adaptability of the semiconductor process equipment to different machines.

[0053] As an optional implementation manner of the present invention, as Figure 1 shown, a pair of adsorption electrodes 121 are arranged in the electrostatic chuck 120, and the power supply component 600 is used to provide electrostatic adsorption voltages with opposite polarities to the two adsorption electrodes 121.

[0054] For a 12-inch wafer (radius r is 0.15 m), the helium pressure P on the back is 20 Torr, the vacuum permittivity ε0 is 8.85e -12 F / m, the relative permittivity ε of alumina is about 10, the thickness d of the electrostatic chuck is 0.2 mm, and the helium flow pressure received by the wafer is:

[0055] F1 = πr 2 P = 187 N;

[0056] If it is necessary to ensure that the electrostatic adsorption force is greater than the helium flow pressure, the electrostatic adsorption voltage v needs to satisfy:

[0057]

[0058] It can be calculated that the electrostatic adsorption voltage v needs to satisfy v < 1600 V, that is, the preset voltage threshold can be 1600 V.

[0059] As an optional implementation manner of the present invention, as Figure 1As shown, the pressure relief valve 230 is used to selectively connect the backflush pipeline 210 to the vacuum pump 240 (Pump) to discharge the temperature-controlled gas in the backflush pipeline 210.

[0060] As an alternative embodiment of the present invention, when the control terminal of the second control switch 420 is connected to the intake valve control signal, if the intake valve control signal is open, the second control switch 420 is triggered to output a high-impedance state signal to the intake valve 220 and a high-level signal to the pressure relief valve 230 (i.e., controlling the intake valve 220 to close and the pressure relief valve 230 to open to discharge the temperature-controlled gas in the backflush pipeline 210); or

[0061] if the intake valve control signal is closed, the second control switch 420 is not triggered, and high-impedance state signals are respectively output to the intake valve 220 and the pressure relief valve 230 (i.e., controlling the intake valve 220 and the pressure relief valve 230 to close together to stop inputting the temperature-controlled gas into the chamber).

[0062] As an alternative embodiment of the present invention, as Figure 2 shown, the intake valve control signal and the pressure relief valve control signal are respectively connected to the intake valve 220 and the pressure relief valve 230 via the second control switch 420.

[0063] Specifically, as Figure 2 shown, the first control switch 410 is a double-pole double-throw relay. The first fixed terminal 411 of the first control switch 410 (i.e., the Pin3 pin of the first control switch 410) is electrically connected to the intake valve control signal output port of the industrial control computer, and the second fixed terminal 412 of the first control switch 410 (i.e., the Pin6 pin of the first control switch 410) is electrically connected to the pressure relief valve control signal output port of the industrial control computer;

[0064] The first normally open contact 413 corresponding to the first fixed terminal 411 (i.e., the Pin4 pin of the first control switch 410) is electrically connected to the control terminal of the second control switch 420, and the second normally open contact 414 corresponding to the second fixed terminal 412 (i.e., the Pin5 pin of the first control switch 410) is left floating;

[0065] The first normally closed contact 415 corresponding to the first fixed terminal 411 (i.e., the Pin2 pin of the first control switch 410) and the second normally closed contact 416 corresponding to the second fixed terminal 412 (i.e., the Pin7 pin of the first control switch 410) are respectively connected to the signal input terminal of the second control switch 420 (i.e., the Pin1 pin of the second control switch 420).

[0066] The second control switch 420 is a double-pole double-throw relay. The third stationary terminal 421 of the second control switch 420 (i.e., the Pin3 pin of the second control switch 420) is electrically connected to the intake valve 220, and the fourth stationary terminal 422 of the second control switch 420 (i.e., the Pin6 pin of the second control switch 420) is electrically connected to the pressure relief valve;

[0067] The third normally open contact 423 corresponding to the third stationary terminal 421 (i.e., the Pin4 pin of the second control switch 420) is left floating, and the fourth normally open contact 424 corresponding to the fourth stationary terminal 422 (i.e., the Pin5 pin of the second control switch 420) is connected to a high level;

[0068] The third normally closed contact 425 corresponding to the third stationary terminal 421 (i.e., the Pin2 pin of the second control switch 420) and the fourth normally closed contact 426 corresponding to the fourth stationary terminal 422 (i.e., the Pin7 pin of the second control switch 420) serve as the signal input terminals of the second control switch 420 and are respectively electrically connected to the first normally closed contact 415 and the second normally closed contact 416.

[0069] As an alternative embodiment of the present invention, as Figure 2 shown, the first end of the electromagnetic winding of the first control switch 410 (i.e., the Pin1 pin of the first control switch 410) is connected to a high level through the third control switch S1, the second end of the electromagnetic winding of the first control switch 410 (i.e., the Pin8 pin of the first control switch 410) is grounded, and the third control switch S1 conducts when the electrostatic adsorption voltage is less than the preset voltage threshold and disconnects when the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold; the first end of the electromagnetic winding of the second control switch 420 (i.e., the Pin1 pin of the second control switch 420) is connected to the first normally open contact 413 corresponding to the first stationary terminal 411, and the second end of the electromagnetic winding of the second control switch 420 (i.e., the Pin8 pin of the second control switch 420) is grounded.

[0070] As an alternative embodiment of the present invention, the interlock circuit 400 further includes a voltage comparator (not shown in the figure). The voltage sensor is used to control the third control switch S1 to disconnect when the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold and control the third control switch S1 to conduct when the electrostatic adsorption voltage is less than the preset voltage threshold.

[0071] As an alternative embodiment of the present invention, the voltage sensor 300 of the semiconductor process equipment can send an electrical signal representing the magnitude of the electrostatic adsorption voltage to the interlock circuit 400, for example, an analog signal. The interlock circuit 400 determines whether the electrostatic adsorption voltage is greater than the preset voltage threshold through its own voltage comparator. Specifically:

[0072] The voltage sensor 300 is used to generate a voltage characterization signal based on the detected electrostatic adsorption voltage. The voltage comparator is used to compare the voltage characterization signal with a threshold level signal corresponding to a preset voltage threshold, and control the third control switch S1 to disconnect when the voltage characterization signal is greater than or equal to the threshold level signal, so that the electromagnetic winding of the first control switch 410 is de-energized, and control the third control switch S1 to conduct when the voltage characterization signal is less than the threshold level signal, so that the electromagnetic winding of the first control switch 410 is energized.

[0073] As an alternative embodiment of the present invention, the interlock circuit 400 further includes a voltage division and regulation circuit, and the voltage division and regulation circuit is used to provide the threshold level signal to the voltage comparator.

[0074] As an alternative embodiment of the present invention, as Figure 2 shown, the interlock circuit 400 further includes an input connector P1, an output connector P2, and a reference voltage connector P3. The input connector P1 is used to receive the control signals of the industrial control computer for the intake valve and the pressure relief valve respectively. The output connector P2 is used to output the switch signals for the intake valve and the pressure relief valve respectively. The reference voltage connector P3 is used to provide a high level Vcc and ground respectively;

[0075] Both the first fixed terminal 411 and the second fixed terminal 412 are connected to the input connector P1 (specifically, the first fixed terminal 411 is connected to the first pin of the input connector P1 through a wiring 401, and the second fixed terminal 412 is connected to the second pin of the input connector P1 through a wiring 402). Both the third fixed terminal 421 and the fourth fixed terminal 422 are connected to the output connector P2 (specifically, the third fixed terminal 421 is connected to the first pin of the output connector P2 through a wiring 403, and the fourth fixed terminal 422 is connected to the second pin of the output connector P2 through a wiring 404);

[0076] The second ends of the electromagnetic windings of the first control switch 410 and the second control switch 420 are both grounded through the reference voltage connector P3. The first ends of the electromagnetic windings of the first control switch 410 and the fourth normally open contacts 424 are both connected to the high level Vcc through the reference voltage connector P3.

[0077] For ease of understanding, as Figure 3 shown is the functional logic schematic diagram of the interlock circuit provided by the embodiment of the present invention. When the industrial control computer does not issue an intake valve opening signal (i.e., the intake valve DO signal) and does not issue a pressure relief valve opening signal (i.e., the pressure relief valve DO signal), no signal is transmitted through the first control switch 410 and the second control switch 420 of the interlock circuit 400 to the intake valve 220 and the pressure relief valve 230, and neither the intake valve 220 nor the pressure relief valve 230 makes any action;

[0078] When the industrial control computer does not send an intake valve opening signal but sends a pressure relief valve opening signal, the interlock circuit 400 first determines whether the electrostatic adsorption voltage is less than a preset voltage threshold. If the electrostatic adsorption voltage is less than the preset voltage threshold, the first control switch 410 conducts, cutting off both the intake valve opening signal and the pressure relief valve opening signal, and the pressure relief valve 230 does not perform any action. If the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold, the pressure relief valve opening signal is normally transmitted to the pressure relief valve 230 through the first control switch 410 and the second control switch 420, causing the pressure relief valve 230 to open.

[0079] When the industrial control computer sends an intake valve opening signal, the interlock circuit 400 first determines whether the electrostatic adsorption voltage is less than a preset voltage threshold. If the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold, neither the first control switch 410 nor the second control switch 420 performs any action, and the intake valve opening signal is normally transmitted to the intake valve 220, causing the intake valve 220 to open. If the electrostatic adsorption voltage is less than the preset voltage threshold, the third control switch S1 conducts, causing the first control switch 410 to be powered on and closed, and then causing the second control switch 420 to close. The control end of the pressure relief valve 230 is connected to the high-level Vcc, and the pressure relief valve 230 opens and discharges the gas in the backflush pipeline to ensure the safety of the cavity 110.

[0080] As a second aspect of the present invention, a semiconductor process equipment is provided, as Figure 1 shown, including a cavity 110, an electrostatic chuck 120, a backflush pipeline, a controller 500 (industrial control computer), a voltage sensor 300, and the interlock circuit 400 provided by the embodiment of the present invention. The electrostatic chuck 120 is disposed in the cavity 110 and is used to adsorb the wafer 10 through electrostatic adsorption. An intake valve 220 and a pressure relief valve 230 are provided on the backflush pipeline 210. The interlock circuit 400 is used to output switch signals to the intake valve 220 and the pressure relief valve 230 according to the electrostatic adsorption voltage of the electrostatic chuck 120 detected by the voltage sensor 300.

[0081] In the semiconductor process equipment provided by the present invention, when the electrostatic adsorption force of the electrostatic chuck 120 is sufficient to fix the wafer 10 (i.e., when the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold), the interlock circuit 400 can normally transmit the control signal according to the industrial control computer to the intake valve 220 and the pressure relief valve 230 to open or close the pressure relief valve. When the electrostatic adsorption force of the electrostatic chuck 120 is too small (i.e., when the electrostatic adsorption voltage is less than the preset voltage threshold), the intake valve 220 is controlled to close and the pressure relief valve 230 is controlled to open, so as to realize local hardware interlock through the voltage sensor 300 and the interlock circuit 400 of the semiconductor process equipment. Even if the industrial control computer makes a misjudgment due to a failure of the power supply component 600 or other reasons and issues an incorrect control signal, the backflush pipeline 210 will not supply gas when the electrostatic adsorption force of the electrostatic chuck 120 is too small, thereby avoiding damage to the wafer 10 caused by drift or flying chip collision, and ensuring the safety of the semiconductor process and the product yield of the wafer 10.

[0082] Moreover, in the present invention, the interlock cut-off control is directly implemented by using the hardware of the interlock circuit 400, and the original control signal of the industrial control computer can be reused to achieve the necessary processes of stopping gas supply + pressure relief, avoiding the development cost of redesigning the relevant software process of the industrial control computer. The corresponding function can be realized by directly adding the device, improving the adaptability of the semiconductor process equipment to different machines.

[0083] As an optional implementation manner of the present invention, as Figure 1 shown, the semiconductor process equipment further includes a solenoid valve group 700. The solenoid valve group 700 includes an intake solenoid valve and a pressure reducing solenoid valve. The intake valve 220 and the pressure relief valve 230 are both pneumatic valves. The intake solenoid valve and the pressure reducing solenoid valve are respectively used to control the on-off of the intake valve 220 and the pressure relief valve 230. The control end of the intake solenoid valve is connected to the intake signal output end 403, and the control end of the pressure reducing solenoid valve is connected to the pressure relief signal output end 404.

[0084] As an optional implementation manner of the present invention, as Figure 1 shown, the semiconductor process equipment further includes a power supply component 600. The power supply component 600 is used to provide an electrostatic adsorption voltage to the electrostatic chuck 120.

[0085] As an optional implementation manner of the present invention, the power supply component 600 includes a high-voltage DC power supply 610 and a DC filter box 620. The DC filter box 620 is connected between the high-voltage DC power supply 610 and the electrostatic chuck 120. The high-voltage DC power supply 610 is used to provide an electrostatic adsorption voltage to the electrostatic chuck 120 through the DC filter box 620.

[0086] As an optional implementation manner of the present invention, the temperature control gas is helium, and the semiconductor process equipment further includes a helium gas source. The helium gas source is used to provide the temperature control gas to the backflush pipeline 210.

[0087] It is understood that the above embodiments are merely exemplary embodiments adopted to illustrate the principles of the present invention. However, the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also regarded as the protection scope of the present invention.

Claims

1. An interlock circuit for a back-blow pipeline of an electrostatic chuck, characterized in that It includes a first control switch and a second control switch, where the first control switch is used to disconnect the pressure relief valve control signal output by the industrial control computer when the electrostatic adsorption voltage of the electrostatic chuck is less than the preset voltage threshold, and connect the intake valve control signal output by the industrial control computer to the control end of the second control switch; the second control switch is used to output a closing signal to the intake valve of the back-blowing pipeline and an opening signal to the pressure relief valve of the back-blowing pipeline when its control end is connected to the intake valve control signal.

2. The interlock circuit according to claim 1, characterized in that When the control end of the second control switch is connected to the intake valve control signal, if the intake valve control signal is open, the second control switch is triggered to output a high-impedance state signal to the intake valve and a high-level signal to the pressure relief valve; or if the intake valve control signal is closed, the second control switch is not triggered, and high-impedance state signals are output to the intake valve and the pressure relief valve respectively.

3. The interlock circuit according to claim 1, characterized in that The first control switch is further used to connect the intake valve control signal and the pressure relief valve control signal to the intake valve and the pressure relief valve respectively when the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold.

4. The interlock circuit according to claim 3, characterized in that The intake valve control signal and the pressure relief valve control signal are connected to the intake valve and the pressure relief valve respectively via the second control switch.

5. The interlock circuit according to claim 1, characterized in that The first control switch is a double-pole double-throw relay. The first stationary terminal of the first control switch is electrically connected to the intake valve control signal output port of the industrial control computer, and the second stationary terminal of the first control switch is electrically connected to the pressure relief valve control signal output port of the industrial control computer; The first normally open contact corresponding to the first stationary terminal is electrically connected to the control end of the second control switch, and the second normally open contact corresponding to the second stationary terminal is left floating; The first normally closed contact corresponding to the first stationary terminal and the second normally closed contact corresponding to the second stationary terminal are respectively connected to the signal input end of the second control switch.

6. The interlock circuit according to claim 5, characterized in that The second control switch is a double-pole double-throw relay. The third stationary terminal of the second control switch is electrically connected to the intake valve, and the fourth stationary terminal of the second control switch is electrically connected to the pressure relief valve; The third normally open contact corresponding to the third stationary terminal is left floating, and the fourth normally open contact corresponding to the fourth stationary terminal is connected to a high level; The third normally closed contact corresponding to the third stationary terminal and the fourth normally closed contact corresponding to the fourth stationary terminal serve as the signal input ends of the second control switch and are respectively electrically connected to the first normally closed contact and the second normally closed contact.

7. The interlock circuit according to claim 6, characterized in that The first end of the electromagnetic winding of the first control switch is connected to a high level through a third control switch, and the second end of the electromagnetic winding of the first control switch is grounded. The third control switch conducts when the electrostatic adsorption voltage is less than the preset voltage threshold and disconnects when the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold; The first end of the electromagnetic winding of the second control switch is connected to the first normally open contact corresponding to the first stationary terminal, and the second end of the electromagnetic winding of the second control switch is grounded.

8. The interlock circuit according to claim 7, characterized in that The interlock circuit further includes a voltage comparator. The voltage sensor is configured to control the third control switch to turn off when the electrostatic adsorption voltage is greater than or equal to the preset voltage threshold, and control the third control switch to turn on when the electrostatic adsorption voltage is less than the preset voltage threshold.

9. The interlock circuit according to claim 7, characterized in that The interlock circuit further includes an input connector, an output connector, and a reference voltage connector. The input connector is configured to receive the control signals of the industrial computer for the intake valve and the pressure relief valve respectively. The output connector is configured to output the switching signals for the intake valve and the pressure relief valve respectively. The reference voltage connector is configured to provide a high level and ground respectively. The first fixed end and the second fixed end are both connected to the input connector. The third fixed end and the fourth fixed end are both connected to the output connector. The second ends of the electromagnetic windings of the first control switch and the second control switch are both grounded through the reference voltage connector. The first ends of the electromagnetic windings of the first control switch and the fourth normally open contacts are both connected to the high level through the reference voltage connector.

10. A semiconductor process equipment, comprising a cavity, an electrostatic chuck, a back-blow pipeline, a controller, a voltage sensor and the interlock circuit according to any one of claims 1 to 9, wherein the electrostatic chuck is disposed in the cavity and is used for adsorbing a wafer by electrostatic adsorption, the voltage sensor is used for detecting the electrostatic adsorption voltage of the electrostatic chuck, an intake valve and a pressure relief valve are disposed on the back-blow pipeline, and the interlock circuit is used for outputting a switch signal to the intake valve and the pressure relief valve according to the electrostatic adsorption voltage of the electrostatic chuck detected by the voltage sensor.

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