Electron beam electrostatic deflection drive power supply

Abstract

The present invention discloses an electron beam electrostatic deflection drive power supply, comprising a data processing unit, a reference power supply unit, a data conversion unit, a power amplifier unit, an output feedback unit, and a power supply unit. The data processing unit, the data conversion unit, the power amplifier unit, and the output feedback unit are sequentially connected. The reference power supply unit is connected to the data conversion unit and is used to provide a reference voltage signal to the data conversion unit. The power supply unit is respectively connected to each unit. The data processing unit is used to receive a scanning position coordinate signal from a host computer. The data conversion unit is used to receive the digital coordinate signal and convert it into a corresponding analog voltage signal. The power amplifier unit is used to linearly amplify the analog voltage signal to drive an electrostatic deflector. The output feedback unit is used to collect the voltage at the output end of the power amplifier unit and feed it back to the host computer to generate correction data for closed-loop control. The present invention has the advantages of high speed and high precision.

Description

Technical Field

[0001] The present invention mainly relates to the technical field of electron beam deflection, and in particular to an electron beam electrostatic deflection driving power supply. Background Art

[0002] Electron beam lithography (EBLI) technology is a key tool in contemporary micro- and nano-manufacturing. Its high resolution allows it to replace photolithography machines for the development of new integrated circuits and the manufacture of small-batch devices. It can also be used to create masks for advanced lithography processes. As a core component of EBLI, the deflector has a decisive influence on the resolution, patterning accuracy, and efficiency of EBLI. The quality of the driver power supply directly impacts the deflector's scanning accuracy and speed.

[0003] Deflectors are categorized by their operating principle into electrostatic and magnetic deflectors. Electrostatic deflectors utilize a constant voltage drive, while magnetic deflectors utilize a constant current drive. Existing electrostatic deflection drive power supply technology suffers from high ripple, low stability, and a narrow dynamic response bandwidth. Consequently, electron beam deflectors are often limited to low-frequency operation, with scanning frequencies typically in the tens or hundreds of kHz. This poor stability makes it difficult to achieve nanometer-scale positioning for electron beam scanning. Consequently, electron beams are currently primarily used in conventional applications such as welding and metal 3D printing, and are unable to meet the process requirements of direct electron beam exposure and mask production. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the present invention provides a high-speed and high-precision electron beam electrostatic deflection driving power supply.

[0005] In order to solve the above technical problems, the technical solution proposed by the present invention is:

[0006] An electron beam electrostatic deflection driving power supply comprises a data processing unit, a reference power supply unit, a data conversion unit, a power amplification unit, an output feedback unit and a power supply unit;

[0007] The data processing unit, the data conversion unit, the power amplification unit and the output feedback unit are connected in sequence; the reference power supply unit is connected to the data conversion unit and is used to provide a reference voltage signal to the data conversion unit; the power supply unit is respectively connected to each unit and is used to provide the required power;

[0008] The data processing unit is used to receive the scanning position coordinate signal from the host computer and send it to the data conversion unit;

[0009] The data conversion unit is used to receive the digital coordinate signal from the data processing unit and convert the digital coordinate signal into a corresponding analog voltage signal;

[0010] The power amplifying unit is used to perform linear power amplification on the analog voltage signal from the data converting unit to drive the electrostatic deflector;

[0011] The output feedback unit is used to collect the voltage at the output end of the power amplifier unit and feed it back to the host computer to generate correction data for closed-loop control.

[0012] As a further improvement of the above technical solution:

[0013] The data processing unit includes a field programmable logic array device, a high-speed optical fiber communication module, a differential parallel bus module and a synchronous clock module; the high-speed optical fiber communication module, the differential parallel bus module and the synchronous clock module are all connected to the field programmable logic array device;

[0014] The high-speed optical fiber communication module is used to interconnect with the optical fiber communication module of the host computer;

[0015] The differential parallel bus module is used to receive scanning position coordinate signals and correction data from the host computer;

[0016] The synchronous clock module is used to align the data output of multiple drive power supplies to ensure the synchronization consistency of the output of each electrode of the electrostatic deflector.

[0017] The reference power supply unit includes a reference source generating circuit, a temperature compensation circuit and an output amplifying circuit;

[0018] The reference source generating circuit is used to generate a reference voltage;

[0019] The temperature compensation circuit is used to calibrate the reference source generation circuit to compensate for the drift of the reference output caused by temperature changes;

[0020] The output amplifier circuit is used to amplify or convert the reference voltage output by the reference source generation circuit into a target reference voltage required by the data conversion unit.

[0021] The data conversion unit includes a main digital-to-analog conversion module, a motion correction module, a position error correction module and a digital-to-analog signal isolation module; the main digital-to-analog conversion module, the motion correction module and the position error correction module are all connected to the digital-to-analog signal isolation module;

[0022] The high-speed motion correction module is used to correct the workpiece stage motion displacement error measured by the laser interferometer;

[0023] The position error correction module is used to correct the position error caused by the installation angle of the deflector;

[0024] The digital-to-analog signal isolation module is used to physically isolate the digital signal output by the data processing unit from the input signal of the data conversion unit.

[0025] The power amplification unit includes an operational amplifier input module, a noise gain compensation module, a power output module and a phase compensation module;

[0026] The operational amplifier input module is used to improve the resolution;

[0027] The power output module is used to increase the driving voltage and current to meet the output load capacity;

[0028] The operational amplifier input module and the power output module are connected in series to form a large composite amplifier circuit;

[0029] The noise gain compensation module and the phase compensation module are used to compensate for the instability of the composite amplifier circuit caused by phase shift changes to avoid oscillation of the circuit.

[0030] The output feedback unit includes a sampling control module, a data acquisition module and a data transmission module; the sampling control module, the data acquisition module and the data transmission module are connected in sequence.

[0031] The sampling control module is implemented by a reed relay, one end of which is connected to the power output module and the other end is connected to the data acquisition module via a coaxial cable.

[0032] The data acquisition module is a multi-channel high-speed data acquisition instrument.

[0033] The data transmission module is connected to the host computer using TCP / IP or GPIB bus.

[0034] The power supply unit is composed of multiple groups of AC-DC linear power supplies.

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] The present invention relies on reference source temperature compensation and closed-loop output feedback to improve the stability of the electrostatic deflection drive power supply; relies on error compensation correction and linear power supply to improve the accuracy of the electrostatic deflection drive power supply; relies on a field programmable logic array, a high-speed differential parallel data bus, and a composite power amplifier circuit with phase compensation to improve the response speed and bandwidth of the electrostatic deflection drive power supply, greatly improving the resolution and speed of electron beam scanning, and can meet the needs of electron beam direct writing lithography and mask production.

[0037] The high-frequency response and high-precision electrostatic deflector driving power supply of the present invention can drive the electron beam to perform high-speed, high-resolution and large-range scanning in the electrostatic deflector, achieving nanometer-level positioning accuracy and a scanning frequency of more than megahertz, which is of great significance to the small-batch manufacturing of third-generation semiconductor chips and the production of photolithography mask plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1This is a block diagram of an embodiment of the electron beam electrostatic deflection driving power supply of the present invention.

[0039] Figure 2 It is a block diagram of a data processing unit in an embodiment of the present invention.

[0040] Figure 3 FIG. 1 is a block diagram of a reference power supply unit according to an embodiment of the present invention.

[0041] Figure 4 FIG. 4 is a block diagram of a data conversion unit according to an embodiment of the present invention.

[0042] Figure 5 FIG. 4 is a block diagram of a power amplification unit according to an embodiment of the present invention.

[0043] Figure 6 FIG. 4 is a block diagram of an output feedback unit according to an embodiment of the present invention.

[0044] Legend: 10. Data processing unit; 101. Field programmable logic array device; 102. High-speed fiber-optic communication module; 103. Differential parallel bus module; 104. Synchronous clock module; 20. Reference power supply unit; 201. Reference source generation circuit; 202. Temperature compensation circuit; 203. Output amplifier circuit; 30. Data conversion unit; 301. Main digital-to-analog conversion module; 302. Motion correction module; 303. Position error correction module; 304. Digital-to-analog signal isolation module; 40. Power amplifier unit; 401. Op amp input module; 402. Noise gain compensation module; 403. Power output module; 404. Phase compensation module; 50. Output feedback unit; 501. Sampling control module; 502. Data acquisition module; 503. Data transmission module; 60. Power supply unit. DETAILED DESCRIPTION

[0045] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0046] like Figure 1 As shown, the high-speed and high-precision electron beam electrostatic deflection driving power supply provided by the embodiment of the present invention includes a data processing unit 10, a reference power supply unit 20, a data conversion unit 30, a power amplification unit 40, an output feedback unit 50 and a power supply unit 60; the output end of the data processing unit 10 is electrically connected to the input end of the data conversion unit 30; the output end of the reference power supply unit 20 is electrically connected to the input end of the data conversion unit 30, and is used to provide a reference voltage signal Vref to the data conversion unit 30; the output end of the data conversion unit 30 is electrically connected to the input end of the power amplification unit 40, and the output end of the power amplification unit 40 is electrically connected to the output feedback unit 50; the power supply unit 60 is used to provide multiple power supply voltages to each digital or analog unit of the driving power supply;

[0047] The data processing unit 10 is used to communicate with the host computer via a high-speed bus, receive the scanning position coordinate data from the host computer, and convert it into an input signal for the data conversion unit 30, thereby controlling the output voltage of the data conversion unit 30;

[0048] The data conversion unit 30 is used to receive the digital coordinate signal from the data processing unit 10 and convert the digital signal into a corresponding analog voltage signal;

[0049] The power amplifier unit 40 is used to linearly power amplify the analog signal from the data conversion unit 30 to output sufficient voltage and current to drive the electrostatic deflector;

[0050] The output feedback unit 50 is used to collect the output voltage and feed it back to the host computer. The host computer adjusts the output in time according to the feedback result, completes the output control closed loop, and improves the stability of the driving power supply.

[0051] like Figure 2 As shown, the core components of the data processing unit can be chips such as MCU, CPU, and FPGA. Considering the real-time performance and high bandwidth of communication, the core of the data processing unit 10 of the present invention uses a field programmable logic array device 101, referred to as FPGA. Compared with microcontrollers and central processing units, FPGA has the advantages of fast response speed, high real-time performance, and parallel operation, making it the most suitable choice for this driver power supply. Because the driver power supply needs to achieve high-speed response, the communication must have low latency and high bandwidth. The input of the data processing unit 10 includes a high-speed fiber optic communication module 102, a differential parallel bus module 103, and a synchronous clock module 104, and the output is multi-channel control data.

[0052] The high-speed fiber-optic communication module 102 is used to interconnect with the fiber-optic communication module of the host computer and can be used for conventional data interaction and command interaction; the differential parallel bus module 103 is used to receive coordinate data and correction data from the host computer. The characteristics of this data are high real-time performance and low latency, so a high-speed differential parallel bus is used to implement it. The bus protocol uses LVDS, with a maximum speed of up to 200Mbps, a data bit width of 32bit, an address bit width of 8bit, and a theoretical bandwidth of up to 800MB / s, which can meet the high-speed and large-bandwidth requirements of the driving power supply; the synchronous clock module 104 is used to align the data outputs of multiple driving power supplies to ensure the synchronous consistency of the outputs of each electrode of the electrostatic deflector.

[0053] The stability of the reference power supply unit 20 output directly affects the accuracy and stability of the driving power output, so the reference power supply unit 20 needs to pay special attention to its temperature drift and thermal hysteresis. Figure 3As shown, the reference power supply unit 20 includes a reference source generating circuit 201, a temperature compensation circuit 202, and an output amplifier circuit 203. The reference source generating circuit 201 is responsible for generating a reference voltage; the temperature compensation circuit 202 is responsible for calibrating the reference source generating circuit 201 to compensate for drift in the reference output due to temperature changes; and the output amplifier circuit 203 is used to amplify or convert the reference voltage output by the reference source circuit 201 to the target reference voltage required by the data conversion unit 30.

[0054] like Figure 4 As shown, the data conversion unit 30 includes a high-precision main digital-to-analog conversion module 301 , a high-speed motion correction module 302 , a position error correction module 303 and a digital-to-analog signal isolation module 304 . The high-precision main digital-to-analog conversion module 301 is implemented using a high-resolution DAC, and its integral and differential nonlinear errors are both less than 1LSB, ensuring good output linearity; the high-speed motion correction module 302 is used to correct the workpiece table motion displacement error measured by the laser interferometer, and is implemented using a high-speed DAC; the position error correction module 303 is used to correct the position error caused by the installation angle of the deflector; the digital-to-analog signal isolation module 304 is used to physically isolate the digital signal output by the data processing unit 10 and the input signal of the data conversion unit 30; the output of the high-precision main digital-to-analog conversion module 301 is fine-tuned and corrected by the motion correction module 302 and the position error correction module 303, which can greatly improve the accuracy of the output drive voltage, thereby improving the electron beam scanning resolution and accuracy; and then through the isolation of the digital-to-analog signal isolation module 304, the influence of digital signal noise on the analog output is reduced, thereby improving the scanning positioning accuracy of the electrostatic deflector, thereby improving the scanning resolution and stability of the electron beam.

[0055] That is, the present invention compensates for the position error of the deflector installation and the displacement error of the substrate movement by adding measures such as motion correction and position compensation, thereby greatly improving the accuracy and stability of the deflection scanning.

[0056] like Figure 5 As shown, the power amplifier unit 40 includes a front-stage op amp input module 401, a noise gain compensation module 402, a rear-stage power output module 403, and a phase compensation module 404. The op amp input module 401 utilizes a low-input-offset-voltage, low-drift op amp to improve resolution. The rear-stage power output module 403 is used to increase the drive voltage and current to meet the output load capacity. The front-stage op amp input module 401 and the rear-stage power output module 403 are connected in series to form a large composite amplifier circuit, which can achieve both precise output and high-speed, high-voltage and high-current amplification. The noise gain compensation module 402 and the phase compensation module 404 compensate for instabilities caused by phase shift variations in the composite amplifier circuit, preventing circuit oscillation. Phase and noise gain compensation improve the dynamic response and bandwidth of the driver power supply.

[0057] like Figure 6 As shown, the output feedback unit 50 is used to sample the output voltage and feed it back to the data processing unit 10 to achieve closed-loop control of the output and improve output accuracy and long-term stability. The specific structure includes a sampling control module 501, a data acquisition module 502, and a data transmission module 503. The sampling control module 501 is implemented as a reed relay, one end of which is connected to the power output module 403 and the other end is connected to the data acquisition module 502 via a coaxial cable. The data processing unit 10 can control the opening or closing of the relay, allowing the host computer to independently select whether to enable output feedback. The data acquisition module 502 is a multi-channel high-speed data acquisition instrument responsible for collecting the output of the power output module 403 into a high-precision 7.5-digit digital multimeter with a maximum voltage sampling resolution of 0.1uV. The data acquisition module 502 can also be connected to an external 8.5-digit digital multimeter with higher precision to improve the voltage sampling resolution. The data transmission module 503 is used to transmit the voltage collected by the data acquisition module 502 to the host computer. The transmission interface can use TCP / IP or GPIB bus. The data is then sent to the data processing unit 10 by the host computer, thus achieving high-precision closed-loop control of the output. The present invention is implemented using a high-precision data acquisition instrument with a 7.5-digit digital multimeter. Compared with the use of high-precision analog-to-digital conversion circuits, this solution can greatly reduce the error caused by the analog-to-digital conversion circuit itself and improve the accuracy of closed-loop feedback.

[0058] Specifically, the power supply unit 60 is composed of multiple groups of AC-DC linear power supplies, which are spatially isolated from other units of the driving power supply. This can reduce the output ripple noise and temperature drift of the driving power supply, improve the resolution of the driving power supply, and meet the high-precision requirements of the driving power supply.

[0059] In specific applications, the data processing unit 10 receives data from the host computer, and after internal analysis, sends the digital signal to the data conversion unit 30. After the digital signal is converted into an analog voltage by the data conversion unit 30, it is sent to the front-stage operational amplifier of the power amplifier unit 40 for weighted summation, and then connected to the post-stage power amplifier of the power amplifier unit 40 to amplify the voltage and current, and finally the output is connected to the electrostatic deflector through a coaxial cable.

[0060] The present invention relies on reference source temperature compensation and closed-loop output feedback to improve the stability of the electrostatic deflection drive power supply; relies on error compensation correction and linear power supply to improve the accuracy of the electrostatic deflection drive power supply; relies on a field programmable logic array, a high-speed differential parallel data bus, and a composite power amplifier circuit with phase compensation to improve the response speed and bandwidth of the electrostatic deflection drive power supply, greatly improving the resolution and speed of electron beam scanning, and can meet the needs of electron beam direct writing lithography and mask production.

[0061] The high-frequency response and high-precision electrostatic deflector driving power supply of the present invention can drive the electron beam to perform high-speed, high-resolution and large-range scanning in the electrostatic deflector, achieving nanometer-level positioning accuracy and a scanning frequency of more than megahertz, which is of great significance to the small-batch manufacturing of third-generation semiconductor chips and the production of photolithography mask plates.

[0062] The above are merely preferred embodiments of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions based on the principles of the present invention are within the scope of protection of the present invention. It should be noted that for those skilled in the art, various improvements and modifications that do not depart from the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An electron beam electrostatic deflection drive power supply, characterized in that: It comprises a data processing unit (10), a reference power supply unit (20), a data conversion unit (30), a power amplification unit (40), an output feedback unit (50) and a power supply unit (60); The data processing unit (10), the data conversion unit (30), the power amplification unit (40) and the output feedback unit (50) are connected in sequence; the reference power supply unit (20) is connected to the data conversion unit (30) and is used to provide a reference voltage signal to the data conversion unit (30); the power supply unit (60) is respectively connected to each unit and is used to provide required power; The data processing unit (10) is used to receive the scanning position coordinate signal from the host computer and send it to the data conversion unit (30); The data conversion unit (30) is used to receive the digital coordinate signal from the data processing unit (10) and convert the digital coordinate signal into a corresponding analog voltage signal; The power amplification unit (40) is used to perform linear power amplification on the analog voltage signal from the data conversion unit (30) to drive the electrostatic deflector; The output feedback unit (50) is used to collect the voltage at the output end of the power amplification unit (40) and feed it back to the host computer to generate correction data for closed-loop control.

2. The electron beam electrostatic deflection driving power supply according to claim 1, characterized in that: The data processing unit (10) comprises a field programmable logic array device (101), a high-speed optical fiber communication module (102), a differential parallel bus module (103) and a synchronous clock module (104); the high-speed optical fiber communication module (102), the differential parallel bus module (103) and the synchronous clock module (104) are all connected to the field programmable logic array device (101); The high-speed optical fiber communication module (102) is used to interconnect with the optical fiber communication module of the host computer; The differential parallel bus module (103) is used to receive scanning position coordinate signals and correction data from a host computer; The synchronous clock module (104) is used to align the data outputs of multiple driving power supplies to ensure the synchronization consistency of the outputs of the various plates of the electrostatic deflector.

3. The electron beam electrostatic deflection driving power supply according to claim 1, characterized in that: The reference power supply unit (20) comprises a reference source generating circuit (201), a temperature compensation circuit (202) and an output amplifying circuit (203); The reference source generating circuit (201) is used to generate a reference voltage; The temperature compensation circuit (202) is used to calibrate the reference source generation circuit (201) to compensate for drift of the reference output caused by temperature changes; The output amplifier circuit (203) is used to amplify or convert the reference voltage output by the reference source generation circuit (201) into a target reference voltage required by the data conversion unit (30).

4. The electron beam electrostatic deflection drive power supply according to claim 1, 2 or 3, characterized in that: The data conversion unit (30) comprises a main digital-to-analog conversion module (301), a motion correction module (302), a position error correction module (303), and a digital-to-analog signal isolation module (304); the main digital-to-analog conversion module (301), the motion correction module (302), and the position error correction module (303) are all connected to the digital-to-analog signal isolation module (304); The motion correction module (302) is used to correct the motion displacement error of the workpiece stage measured by the laser interferometer; The position error correction module (303) is used to correct the position error caused by the installation angle of the deflector; The digital-to-analog signal isolation module (304) is used to physically isolate the digital signal output by the data processing unit (10) from the input signal of the data conversion unit (30).

5. The electron beam electrostatic deflection driving power supply according to claim 1, 2 or 3, characterized in that: The power amplification unit (40) comprises an operational amplifier input module (401), a noise gain compensation module (402), a power output module (403) and a phase compensation module (404); The operational amplifier input module (401) is used to improve resolution; The power output module (403) is used to increase the driving voltage and current to meet the output load capacity; The operational amplifier input module (401) and the power output module (403) are connected in series to form a large composite amplifier circuit; The noise gain compensation module (402) and the phase compensation module (404) are used to compensate for the instability of the composite amplifier circuit caused by phase shift changes to avoid oscillation of the circuit.

6. The electron beam electrostatic deflection driving power supply according to claim 5, characterized in that: The output feedback unit (50) comprises a sampling control module (501), a data acquisition module (502) and a data transmission module (503); the sampling control module (501), the data acquisition module (502) and the data transmission module (503) are connected in sequence.

7. The electron beam electrostatic deflection driving power supply according to claim 6, characterized in that: The sampling control module (501) is implemented by a reed relay, one end of which is connected to the power output module (403), and the other end of which is connected to the data acquisition module (502) via a coaxial cable.

8. The electron beam electrostatic deflection driving power supply according to claim 6, characterized in that: The data acquisition module (502) is a multi-channel high-speed data acquisition instrument.

9. The electron beam electrostatic deflection driving power supply according to claim 6, characterized in that: The data transmission module (503) is connected to the host computer using TCP / IP or GPIB bus.

10. The electron beam electrostatic deflection driving power supply according to claim 6, characterized in that: The power supply unit (60) is composed of multiple groups of AC-DC linear power supplies.

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