An electron beam lithography machine sample handling system

Abstract

The application provides an electron beam lithography machine sample taking and delivering system, which is an electron beam lithography machine sample taking and delivering system based on a cavity isolation technology, a pre-receiving cavity (equipped with a two-stage vacuum system of a molecular pump and a mechanical pump) with independent vacuum pumping capacity is arranged to dynamically isolate the main sample cavity, and a door valve is used for realizing local vacuum maintenance during sample transmission. The technical effect is that: through the pre-receiving cavity pre-vacuum and the sample cavity vacuum isolation mechanism, the sample changing operation only needs to perform local vacuum pumping on the pre-receiving cavity for a short time, and compared with the traditional whole cavity vacuum pumping process, the speed is significantly improved; the molecular pump group operation time is shortened, the single sample changing energy consumption is reduced; the modular vacuum system design reduces the equipment area and the vacuum pipeline complexity, and through the closed loop control of the air release valve and the vacuum gauge, the system reliability and the maintenance convenience are significantly improved.

Description

Technical Field

[0001] This application relates to the field of sample delivery device technology, and more specifically, to a sample delivery system for an electron beam lithography machine. Background Technology

[0002] Existing electron beam lithography (EBL) systems suffer from significant efficiency bottlenecks in sample handling: their large-volume vacuum chambers require a complete vacuum de-vacuuming cycle. Due to physical limitations in chamber volume and vacuum level requirements, each vacuuming cycle is time-consuming. This cyclical operation directly reduces the equipment's average daily effective processing time, while also leading to high energy consumption of the molecular pump assembly and a surge in manual monitoring costs. This problem is particularly pronounced in high-frequency sample changeover scenarios such as nanoimprint lithography and multi-project wafer processing, becoming a key factor restricting the overall capacity of the equipment.

[0003] From a system architecture perspective, current vacuum control systems suffer from structural flaws: they employ a three-stage linkage scheme of a mechanical pump (roughing pump), a molecular pump (turbo pump), and a vacuum gauge, relying on a centralized control unit for closed-loop regulation. This traditional architecture results in low system integration, and the parallel operation of multiple pump groups increases the complexity of vacuum piping. The resulting physical drawbacks include increased overall system weight and higher lifecycle maintenance costs. Utility Model Content

[0004] The purpose of this application is to provide a sample delivery system for an electron beam lithography machine, which solves the problems of existing large-volume vacuum chambers requiring a complete vacuum breaking-vacuuming cycle, resulting in long vacuuming time and soaring costs.

[0005] This application provides an electron beam lithography machine sample delivery system, comprising: a sample delivery stage, a sample chamber, and a pre-receiving chamber; a gate valve is provided between the sample chamber and the pre-receiving chamber; when the gate valve is in the open state, the sample chamber and the pre-receiving chamber are connected; when the gate valve is in the closed state, the sample chamber and the pre-receiving chamber are separated.

[0006] The pre-collection chamber is connected to a molecular pump, and the pre-collection chamber is connected to a mechanical pump via a mechanical pump valve; the molecular pump and the mechanical pump are used to evacuate the pre-collection chamber;

[0007] The pre-recovery chamber is also equipped with a vent valve and a vacuum gauge; the vent valve is used to release the gas pressure in the pre-recovery chamber; the vacuum gauge is used to monitor the vacuum level in the pre-recovery chamber.

[0008] The sample delivery stage is used to transfer the sample between the pre-receiving chamber and the sample chamber when the gate valve is in the open state.

[0009] The above technical solution provides an electron beam lithography sample handling system based on chamber isolation technology. It dynamically isolates a pre-collection chamber (equipped with a two-stage vacuum system consisting of a molecular pump and a mechanical pump) with independent vacuum pumping capabilities from the main sample chamber, and maintains local vacuum during sample transfer using gate valve control. The technical advantages are: the pre-vacuuming mechanism of the pre-collection chamber and the vacuum isolation mechanism of the sample chamber allow for sample change operations that only require a short-duration local vacuuming of the pre-collection chamber, significantly accelerating the process compared to traditional full-chamber vacuuming; the molecular pump group's operating time is shortened, reducing energy consumption per sample change; the modular vacuum system design reduces the equipment's footprint and the complexity of the vacuum piping; and the closed-loop control of the vent valve and vacuum gauge significantly improves system reliability and maintenance convenience.

[0010] In some alternative implementations, a magnetic switch is also included;

[0011] A magnetic switch is installed at both the initial and final positions of the valve. The magnetic switches are used to detect the open and closed states of the valve.

[0012] In some optional implementations, a limit switch is also included;

[0013] A limit switch is installed at both the initial and final positions of the vent valve. The limit switches are used to detect the position of the vent valve.

[0014] In the above technical solution, the limit switch can accurately determine whether the valve has reached the preset end position by providing real-time feedback on the opening and closing status of the vent valve. When the vent valve needs to be opened, the end position limit switch ensures that the valve is fully open, avoiding incomplete pressure release due to mechanical jamming. When the vent valve needs to be closed, the initial position limit switch confirms that the seal is in place, preventing vacuum maintenance failure due to minor leaks.

[0015] In some optional implementations, it also includes: a lower-level controller, a lower-level screen, and a relay;

[0016] The lower-level controller connects to the vacuum gauge, limit switch, magnetic switch, lower-level screen, molecular pump, and relay;

[0017] The relay connects the mechanical pump valve, gate valve, and vent valve.

[0018] The above technical solution incorporates a localized control system comprised of a lower-level controller, a lower-level screen, and relay modules. The lower-level controller (PLC or embedded system) directly drives actuators such as molecular pumps and valves. The lower-level screen and controller work together to achieve real-time status visualization and localized operation support.

[0019] Among its features are real-time status visualization, which synchronously displays the pre-collection chamber vacuum level, valve position status, and pump operating power; and localized operation support, which allows for basic operations such as sample change process initiation and vacuum threshold setting without relying on a host computer.

[0020] In some optional implementations, the lower-level controller includes: a main control circuit, a lower-level serial communication circuit, a network communication circuit, a solenoid valve control circuit, a pneumatic valve control circuit, a molecular pump control circuit, a magnetic switch signal input circuit, and a limit switch signal input circuit;

[0021] The serial communication circuit, network communication circuit, solenoid valve control circuit, pneumatic valve control circuit, molecular pump control circuit, magnetic switch signal input circuit, and limit switch signal input circuit of the lower-level machine are all connected to the main control circuit;

[0022] The lower-level serial communication circuit is also connected to the lower-level screen, the network communication circuit is also connected to the vacuum gauge, the solenoid valve control circuit is also connected to the relay, the pneumatic valve control circuit is also connected to the relay, the molecular pump control circuit is also connected to the molecular pump, the magnetic switch signal input circuit is also connected to the magnetic switch, and the limit switch signal input circuit is also connected to the limit switch.

[0023] In some optional implementations, the lower-level controller further includes: a voltage input circuit, a BUCK step-down circuit, and an LDO step-down circuit;

[0024] The voltage input circuit is connected to the BUCK step-down circuit, the BUCK step-down circuit is connected to the LDO step-down circuit and the lower-level machine screen, and the LDO step-down circuit is also connected to the main control circuit.

[0025] The voltage input circuit is also connected to the network communication circuit and the molecular pump control circuit.

[0026] In some optional implementations, the lower-level controller further includes a reset circuit; the reset circuit is connected to the main control circuit and is used to reset the program when the program is stuck by using a reset button.

[0027] In some optional implementations, the lower-level controller further includes a download circuit; the download circuit is connected to the main control circuit and is used to download the control program of the debugging instrument.

[0028] In some optional implementations, the lower-level controller further includes a boot mode selection circuit; the boot mode selection circuit is connected to the main control circuit and is used to enable the program to boot from the user flash memory. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 A schematic diagram of an electron beam lithography sample loading and unloading system provided in this application embodiment;

[0031] Figure 2 This is a schematic diagram of the functional modules of the electron beam lithography sample loading and unloading system provided in this embodiment;

[0032] Figure 3 This is a schematic diagram of the lower-level controller device provided in the embodiments of this application;

[0033] Figure 4 This is a schematic diagram of the structure of the control box housing provided in an embodiment of this application;

[0034] Figure 5 The circuit structure diagram of each module in the lower-level controller provided in the embodiments of this application;

[0035] Figure 6 A three-dimensional structural diagram of the lower-level controller provided in the embodiments of this application;

[0036] Figure 7 This is a flowchart of the automatic vacuuming and vacuum releasing process provided in this embodiment;

[0037] Figure 8 This is a flowchart of the manual control process provided in this embodiment;

[0038] Figure 9 The vacuum curve inside the cavity during evacuation of the pre-shrinking cavity is provided in the embodiments of this application;

[0039] Figure 10 This is a schematic diagram of the power supply connection of each module of the lower-level controller provided in the embodiments of this application;

[0040] Figure 11 This is a schematic diagram of the signal connections of each module of the lower-level controller provided in the embodiments of this application.

[0041] Icons: 1-Control box housing, 2-Lower-level controller, 3-Lower-level screen, 4-220VAC to 24VDC switching power supply, 5-Relay, 6-Terminal block, 101-Lower-level controller connection hole, 102-Lower-level controller electrical input / output hole, 103-Lower-level controller support plate, 104-Relay electrical output hole, 105-Relay support plate, 201-Main control chip, 202-Reset button, 203-Program download pin header, 204-Network port, 205-4P socket, 206-DB15 interface, 207-Cold start pin header, 208-Signal input terminal block, 209-Signal output terminal block. Detailed Implementation

[0042] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0043] Please refer to Figure 1 , Figure 1 A schematic diagram of an electron beam lithography sample delivery system provided in this application embodiment includes: a sample delivery stage, a sample chamber, and a pre-receiving chamber; a gate valve is provided between the sample chamber and the pre-receiving chamber; when the gate valve is in the open state, the sample chamber and the pre-receiving chamber are connected; when the gate valve is in the closed state, the sample chamber and the pre-receiving chamber are separated; a molecular pump is connected to the pre-receiving chamber, and the pre-receiving chamber is connected to a mechanical pump through a mechanical pump valve; the molecular pump and the mechanical pump are used to evacuate the pre-receiving chamber; the pre-receiving chamber is also provided with a vent valve and a vacuum gauge; the vent valve is used to release the gas pressure in the pre-receiving chamber; the vacuum gauge is used to monitor the vacuum level in the pre-receiving chamber; the sample delivery stage is used to transfer the sample between the pre-receiving chamber and the sample chamber when the gate valve is in the open state.

[0044] The sample chamber and the pre-collection chamber are separated by a valve. The pre-collection chamber is equipped with a molecular pump, vacuum gauge, vent valve, limit switch, and magnetic switch. It is connected to a mechanical pump valve via a pipe, thereby controlling the mechanical pump's operation. The electron beam lithography sample handling system achieves efficient sample handling and a stable vacuum environment through the coordinated operation of the pre-collection chamber, sample chamber, and other components. The sample chamber, the main chamber for experimental and lithography operations, must maintain a high vacuum to meet the requirements of the lithography process. The pre-collection chamber is used for preliminary sample processing, including evacuation and venting operations, to avoid directly affecting the vacuum state within the sample chamber. The mechanical and molecular pumps are responsible for evacuating the pre-collection chamber, transitioning from atmospheric pressure to a high vacuum. The vacuum gauge monitors the vacuum level within the pre-collection chamber in real time. The valve connects the pre-collection chamber and sample chamber, controlling the isolation and communication between the two chambers. The vent valve releases the pressure within the pre-collection chamber, restoring it to normal atmospheric pressure for safe sample handling and replacement. The sample delivery stage is used for the transfer of samples between the pre-receiving chamber and the sample chamber.

[0045] This application provides a sample handling system for an electron beam lithography machine based on chamber isolation technology. By setting up a pre-collection chamber (equipped with a two-stage vacuum system consisting of a molecular pump and a mechanical pump) with independent vacuum pumping capabilities and dynamically isolating it from the main sample chamber, local vacuum maintenance during sample transfer is achieved using gate valve control. The technical advantages are: the pre-vacuuming mechanism of the pre-collection chamber and the vacuum isolation mechanism of the sample chamber allow for sample change operations that only require a short-duration local vacuuming of the pre-collection chamber, significantly accelerating the process compared to traditional full-chamber vacuuming; the molecular pump group's operating time is shortened, reducing energy consumption per sample change; the modular vacuum system design reduces the equipment's footprint and the complexity of the vacuum piping; and the closed-loop control of the vent valve and vacuum gauge significantly improves system reliability and maintenance convenience.

[0046] In some alternative implementations, the valve may also include: magnetic switches; one magnetic switch is installed at the initial position and another at the final position of the valve, the magnetic switches being used to detect the open and closed states of the valve.

[0047] In some optional implementations, the valve may also include: limit switches; one limit switch is installed at the initial position and the other at the final position of the vent valve, and the limit switches are used to detect the position of the vent valve.

[0048] Specifically, an NPN magnetic switch is installed at both the initial and final positions of the valve. This switch outputs a low level when a signal is detected, which is then used to detect the opening and closing status of the valve. A limit switch is installed at both the initial and final positions of the vent valve. Through the signal feedback from these two switches, precise monitoring and automated control of the positions of the valve and vent valve can be achieved, ensuring the safety and reliability of the system operation.

[0049] In this embodiment, the limit switch accurately determines whether the vent valve has reached the preset end position by providing real-time feedback on the opening and closing status of the vent valve. When the vent valve needs to be opened, the end position limit switch ensures that the valve is fully open, preventing incomplete pressure release due to mechanical jamming. When the vent valve needs to be closed, the initial position limit switch confirms that the seal is in place, preventing vacuum maintenance failure due to minor leaks.

[0050] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the functional modules of the electron beam lithography sample loading and unloading system provided in this embodiment;

[0051] The sample handling system of the electron beam lithography machine also includes: a lower-level controller, a lower-level screen, and relays; the lower-level controller is connected to a vacuum gauge, limit switch, magnetic switch, lower-level screen, molecular pump, and relays; the relays are connected to mechanical pump valves, gate valves, and vent valves.

[0052] The lower-level controller receives commands from the lower-level computer screen and jointly controls the operation of the mechanical pump, molecular pump, gate valve, and vent valve, as well as the vacuuming and venting processes. Simultaneously, the lower-level controller receives signals from the vacuum gauge, molecular pump, magnetic switch, and limit switches. Relays are connected to the mechanical pump valves, gate valves, and vent valves to execute specific operations. The entire system has a compact structure, with all components working collaboratively to achieve efficient sample handling and vacuum processing.

[0053] In this embodiment, a localized control system consisting of a lower-level controller, a lower-level screen, and a relay module is introduced. The lower-level controller (PLC or embedded system) directly drives actuators such as molecular pumps and valves. The lower-level screen and the lower-level controller work together to achieve real-time status visualization and localized operation support.

[0054] Among its features are real-time status visualization, which synchronously displays the pre-collection chamber vacuum level, valve position status, and pump operating power; and localized operation support, which allows for basic operations such as sample change process initiation and vacuum threshold setting without relying on a host computer.

[0055] Please refer to Figure 3 , Figure 3 This is a schematic diagram of the lower-level controller device provided in this application embodiment. The lower-level controller device has dimensions of 285×100×70mm and includes a control box housing 1, a lower-level controller 2, a lower-level screen 3, a 220VAC to 24VDC switching power supply 4, a relay 5, and a terminal block 6. The control box housing 1 has a rectangular structure and is divided into multiple layers to house the lower-level controller 2 and related components. The lower-level controller 2 is located on the upper layer of the control box housing 1 and is used to realize signal processing and control of various functional modules. The lower-level screen 3 is on the outside of the housing and embedded in the electron beam lithography machine body, used to display system status and operation information in real time. The 220VAC to 24VDC switching power supply 4 is arranged below the circuit board to convert 220V AC power into 24V DC power for the lower-level controller 2 and electrical components. The relay 5 is installed on the upper part of the housing, close to the lower-level controller 2, to complete the corresponding signal input / output and equipment operation control. Terminal block 6 is located below relay 5 and is used to connect external devices and sensors and centrally manage complex circuit connections. The overall structure is compact and the modular design facilitates maintenance and expansion, making it suitable for the control and operation of complex systems.

[0056] Please refer to Figure 4 , Figure 4This is a schematic diagram of the control box housing provided in an embodiment of this application. The control box housing 1 includes a lower-level controller connection hole 101 for fixing the lower-level controller 2; a lower-level controller electrical input / output hole 102 for leading out electrical lines from the lower-level controller 2; a lower-level controller support plate 103 for supporting the lower-level controller 2; a relay electrical output hole 104 for leading out electrical lines from the relay 5; and a relay support plate 105 for supporting the relay.

[0057] Please refer to Figure 5 and Figure 6 , Figure 5 The circuit structure diagram of each module in the lower-level controller provided in the embodiments of this application is shown. Figure 6 This is a three-dimensional structural diagram of the lower-level controller provided in an embodiment of this application.

[0058] The lower-level controller includes: a main control circuit, a lower-level serial communication circuit, a network communication circuit, a solenoid valve control circuit, a pneumatic valve control circuit, a molecular pump control circuit, a magnetic switch signal input circuit, and a limit switch signal input circuit. The lower-level serial communication circuit, network communication circuit, solenoid valve control circuit, pneumatic valve control circuit, molecular pump control circuit, magnetic switch signal input circuit, and limit switch signal input circuit are all connected to the main control circuit. The lower-level serial communication circuit is also connected to the lower-level screen; the network communication circuit is also connected to a vacuum gauge; the solenoid valve control circuit is also connected to a relay; the pneumatic valve control circuit is also connected to a relay; the molecular pump control circuit is also connected to a molecular pump; the magnetic switch signal input circuit is also connected to a magnetic switch; and the limit switch signal input circuit is also connected to a limit switch.

[0059] Please refer to Figure 10 , Figure 10 This diagram illustrates the power supply connections of each module in the lower-level controller provided in this embodiment. The lower-level controller also includes: a voltage input circuit, a BUCK step-down circuit, and an LDO step-down circuit;

[0060] The voltage input circuit is connected to the BUCK step-down circuit, the BUCK step-down circuit is connected to the LDO step-down circuit and the lower-level machine screen, and the LDO step-down circuit is also connected to the main control circuit.

[0061] The voltage input circuit is also connected to the network communication circuit and the molecular pump control circuit.

[0062] Please refer to Figure 11 , Figure 11 This is a schematic diagram of the signal connections of each module of the lower-level controller provided in the embodiments of this application.

[0063] In some optional implementations, the lower-level controller further includes a reset circuit; the reset circuit is connected to the main control circuit and is used to reset the program when the program is stuck by using a reset button.

[0064] In some optional implementations, the lower-level controller further includes a download circuit; the download circuit is connected to the main control circuit and is used to download the control program of the debugging instrument.

[0065] In some optional implementations, the lower-level controller further includes a boot mode selection circuit; the boot mode selection circuit is connected to the main control circuit and is used to enable the program to boot from the user flash memory.

[0066] In one specific embodiment, the main control circuit uses an STM32F103RCT6 main control chip. The main control circuit controls each lower-level hardware through the main control chip 201. The lower-level controller 2 supplies the 24V DC power input from the voltage input circuit to the network communication circuit and the molecular pump control circuit. The BUCK step-down circuit converts the 24V DC power input from the voltage input circuit into the 5V DC voltage for the lower-level screen. The LDO step-down circuit converts the 5V DC power converted by the BUCK step-down circuit into the 3.3V DC power for the main control chip 201. The reset circuit resets the program when it unexpectedly freezes through the reset button 202. The download circuit downloads the instrument's control program via the program download header 203; the start-up mode selection circuit forces all connections to 0, enabling the program to boot from the user's flash memory; the network communication circuit reads the vacuum gauge's vacuum level via network port 204; the lower-level serial communication circuit interacts with the lower-level screen 3 via a 4-pin socket 205; the molecular pump control circuit has a DB15 interface 206 and a cold-start header 207 for communicating with the molecular pump and performing cold starts. The magnetic switch signal input circuit and limit switch signal input circuit read and receive signals via signal input terminal block 208; the solenoid valve control circuit and pneumatic valve control circuit control the gate valve, vent valve, and mechanical pump valve via signal output terminal block 209.

[0067] Specifically, the vacuum gauge is model WRG-S-NW25. This vacuum gauge has a maximum power consumption of 2W, a power supply voltage of DC 24V, and an output signal ranging from 1.8V to 10.2V. The lower-level controller 2 collects the voltage output from the vacuum gauge into the main control chip via a 12-bit ADC, and converts the voltage V to the vacuum level P using the following formula:

[0068] P = 10 1.5V-10 Pa

[0069] The molecular pump is model nETX85. The cold start header 207 of the lower-level controller 2 can control the start-up and communication of the molecular pump. The DB15 interface 206 of the lower-level controller 2 is connected to the molecular pump to provide power and control it via RS232 protocol. When cold start communication is enabled, the molecular pump can run under serial control and monitoring to achieve hot start. The communication protocol is as follows:

[0070] Pump start command:

[0071] ！ C 8 5 2 sp 1 cr

[0072] Stop pump command:

[0073] ！ C 8 5 2 sp 0 cr

[0074] Command to measure motor speed:

[0075] ！ ？ V 8 5 2 cr

[0076] reply:

[0077] ＝ V 8 5 2 sp d d d d ； h h h h h h h h cr

[0078] Furthermore, when a command to measure the motor is sent to the molecular pump, the returned value contains "dddd," which represents the molecular pump frequency. The lower-level machine processes this returned value and reads the frequency value separately. The conversion formula between frequency and rotational speed is as follows:

[0079]

[0080] Where n is the motor speed, f is the frequency read by the molecular pump, and p is the number of pole pairs of the rotating magnetic field of the motor. The number of pole pairs of the motor used in this molecular pump is 1.

[0081] Please refer to Figure 7 , Figure 7 This is a flowchart of the automatic vacuuming and devastating process provided in this embodiment. After the system starts, when the vacuuming button is clicked on the lower-level machine screen, the mechanical pump valve opens, and the mechanical pump starts to initially evacuate the pre-collection chamber. Subsequently, the molecular pump starts to further reduce the vacuum level inside the chamber. When the vacuum gauge detects that the vacuum level inside the chamber reaches 10... -3 When the pressure is below a certain level (Pa), the system confirms that the vacuum level meets the requirements, allowing the valve to remain open and completing the vacuuming process. In the vacuum release process, the valve and molecular pump are first closed to ensure the chamber is sealed. Then, the system checks if the molecular pump speed is zero; after confirming a safe shutdown, the mechanical pump valve is closed, and the vent valve is opened for 7 seconds to restore the chamber pressure to atmospheric pressure. After depressurization, the vent valve is closed, ending the vacuum release process. The entire process automates the vacuuming and releasing operations, ensuring safety and efficiency.

[0082] Please refer to Figure 8 , Figure 8 This embodiment provides a manual control process flow diagram. The user operates and controls the system through the lower-level machine screen. The specific process is as follows:

[0083] First, the operator starts the mechanical pump valve and confirms that the mechanical pump is running normally. If the mechanical pump fails to start, the user is prompted to recheck the system status. Once the mechanical pump is running normally, the operator confirms that the mechanical pump valve is closed. If it is not closed, the user is prompted to manually close the mechanical pump valve. Next, the operator manually starts the molecular pump and confirms its normal operation via the molecular pump's status feedback signal. If the molecular pump fails to start, the user is prompted to check the relevant hardware connections or try starting the molecular pump again.

[0084] After the molecular pump is running normally, the user can determine whether the vacuum level in the chamber has reached 10 by reading the data fed back by the vacuum gauge. -3 If the vacuum level is below a certain value (e.g., Pa), the mechanical pump and molecular pump will continue to operate until the requirement is met. Once the vacuum level meets the standard, the system will indicate that the valve can be manually opened for sampling or other operations.

[0085] During the vacuum release process, the user first confirms that the gate valves and molecular pumps are closed to ensure system tightness. Then, the operator manually opens the vent valve, holds it for a period of time, and then manually closes it to restore the pressure inside the chamber to atmospheric pressure. This procedure allows the operator to efficiently and flexibly control the vacuum system manually, while feedback signals ensure operational safety and reliability.

[0086] Please refer to Figure 9 , Figure 9 The vacuum curve inside the cavity during evacuation is provided in this embodiment of the application. From the vacuum curve plotted based on the data from the vacuum gauge received by the lower-level controller, it can be seen that the entire evacuation process takes approximately 5 minutes to achieve the change in pressure from normal atmospheric pressure to the required pressure inside the cavity. Since each vertical coordinate on the y-axis is not a fixed difference, the following formula is used to send the converted vacuum gauge data read by the lower-level controller to the lower-level screen:

[0087]

[0088] Where x is the actual vacuum value read, and y is the vacuum value converted by the formula and sent to the host computer.

[0089] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the displayed or discussed mutual couplings, direct couplings, or communication connections may be through some communication interfaces; indirect couplings or communication connections between devices or units may be electrical, mechanical, or other forms.

[0090] Furthermore, the units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0091] Furthermore, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0092] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0093] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A sample feeding system for an electron beam lithography machine, characterized in that, include: Sample delivery stage, sample chamber, and pre-receiver chamber; A valve is provided between the sample chamber and the pre-collection chamber; When the valve is open, the sample chamber and the pre-collection chamber are connected; when the valve is closed, the sample chamber and the pre-collection chamber are separated. The pre-collection chamber is connected to a molecular pump, and the pre-collection chamber is connected to a mechanical pump via a mechanical pump valve; the molecular pump and the mechanical pump are used to evacuate the pre-collection chamber; The pre-shrinking chamber is also equipped with a vent valve and a vacuum gauge; the vent valve is used to release the air pressure in the pre-shrinking chamber. The vacuum gauge is used to monitor the vacuum level in the pre-collection chamber; The sample delivery stage is used to transfer the sample between the pre-receiving chamber and the sample chamber when the gate valve is in the open state.

2. The system as described in claim 1, characterized in that, Also includes: Magnetic switch; A magnetic switch is installed at both the initial and final positions of the valve, and the magnetic switches are used to detect the open and closed states of the valve.

3. The system as described in claim 2, characterized in that, Also includes: Limit switches; A limit switch is installed at both the initial and final positions of the vent valve, and the limit switches are used to detect the position of the vent valve.

4. The system as described in claim 3, characterized in that, Also includes: Lower-level controller, lower-level screen, and relays; The lower-level controller connects to the vacuum gauge, limit switch, magnetic switch, lower-level screen, molecular pump, and relay; The relay connects the mechanical pump valve, gate valve, and vent valve.

5. The system as described in claim 4, characterized in that, The lower-level controller includes: a main control circuit, a lower-level serial communication circuit, a network communication circuit, a solenoid valve control circuit, a pneumatic valve control circuit, a molecular pump control circuit, a magnetic switch signal input circuit, and a limit switch signal input circuit; The serial communication circuit, network communication circuit, solenoid valve control circuit, pneumatic valve control circuit, molecular pump control circuit, magnetic switch signal input circuit, and limit switch signal input circuit of the lower-level machine are all connected to the main control circuit; The lower-level serial communication circuit is also connected to the lower-level screen, the network communication circuit is also connected to the vacuum gauge, the solenoid valve control circuit is also connected to the relay, the pneumatic valve control circuit is also connected to the relay, the molecular pump control circuit is also connected to the molecular pump, the magnetic switch signal input circuit is also connected to the magnetic switch, and the limit switch signal input circuit is also connected to the limit switch.

6. The system as described in claim 5, characterized in that, The lower-level controller also includes: a voltage input circuit, a BUCK step-down circuit, and an LDO step-down circuit; The voltage input circuit is connected to the BUCK step-down circuit, the BUCK step-down circuit is connected to the LDO step-down circuit and the lower-level machine screen, and the LDO step-down circuit is also connected to the main control circuit. The voltage input circuit is also connected to the network communication circuit and the molecular pump control circuit.

7. The system as described in claim 5, characterized in that, The lower-level controller also includes a reset circuit; the reset circuit is connected to the main control circuit and is used to reset the program when the program is stuck by using the reset button.

8. The system as described in claim 5, characterized in that, The lower-level controller also includes a download circuit; the download circuit is connected to the main control circuit and is used to download the control program for debugging the instrument.

9. The system as described in claim 5, characterized in that, The lower-level controller also includes a boot mode selection circuit; the boot mode selection circuit is connected to the main control circuit and is used to enable the program to boot from the user's flash memory.

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