Vacuum control system of photoetching machine

Abstract

The invention provides a vacuum control system of a photoetching machine, which comprises a pre-pumping cavity, a working cavity, a photoetching machine cavity, a gate valve, a first vacuum gauge, a communication valve, a second vacuum gauge, a mechanical pump, a first mechanical pump valve, a molecular pump, a first control device and a second control device, the working cavity is arranged between the pre-pumping cavity and the photoetching machine cavity, the gate valve is arranged between the sample conveying tracks corresponding to the working cavity and the pre-pumping cavity respectively, the mechanical pump is connected with the pre-pumping cavity through the first mechanical pump valve, the first vacuum gauge is connected with the pre-pumping cavity, the communicating valve is arranged between the pre-pumping cavity and the working cavity, the molecular pump is connected with the working cavity, and the second vacuum gauge is connected with the working cavity. The second vacuum gauge is connected with the photoetching machine cavity, the photoetching machine cavity is communicated with the working cavity, and the second control equipment is respectively connected with the first control equipment, the gate valve, the first vacuum gauge, the communication valve, the second vacuum gauge, the mechanical pump, the molecular pump and the first mechanical pump valve.

Description

Technical Field

[0001] This application relates to the field of photolithography technology, and in particular to a vacuum control system for a photolithography machine. Background Technology

[0002] In existing technologies, samples are placed in a vacuum chamber and exposed using a photolithography machine, typically an electron beam lithography (EBL) machine. After exposure, the sample needs to be removed from the chamber, followed by vacuuming and devastating operations. Due to the large volume of the sample chamber, each vacuuming process is time-consuming, often requiring several hours to reach the required vacuum level. This significantly reduces experimental efficiency and increases system energy consumption and operating costs, especially in applications requiring frequent sample changes. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide at least one vacuum control system for a lithography machine, which reduces the technical problem of long vacuuming time caused by frequent sample feeding and sampling by setting a pre-evacuation chamber and a gate valve, thereby achieving the technical effect of reducing vacuuming time.

[0004] This application mainly includes the following aspects: In a first aspect, embodiments of this application provide a vacuum control system for a lithography machine. The vacuum control system includes a pre-evacuation chamber, a working chamber, a lithography machine cavity, a gate valve, a first vacuum gauge, a connecting valve, a second vacuum gauge, a mechanical pump, a first mechanical pump valve, a molecular pump, a first control device, and a second control device. The working chamber is disposed between the pre-evacuation chamber and the lithography machine cavity. The gate valve is disposed between sample delivery tracks corresponding to the working chamber and the pre-evacuation chamber. The mechanical pump is connected to the pre-evacuation chamber via the first mechanical pump valve. The first vacuum gauge is connected to the pre-evacuation chamber. The connecting valve is disposed between the pre-evacuation chamber and the first vacuum gauge. Between the pre-evacuation chamber and the working chamber, the molecular pump is connected to the working chamber, and the second vacuum gauge is connected to the lithography machine chamber. The lithography machine chamber is in communication with the working chamber. The second control device is connected to the first control device, the gate valve, the first vacuum gauge, the connecting valve, the second vacuum gauge, the mechanical pump, the molecular pump, and the first mechanical pump valve. The first control device is configured to: acquire the working chamber vacuum level of the working chamber collected by the second vacuum gauge in real time through the second control device; and, if the working chamber vacuum level does not reach a preset working chamber vacuum level... When the working chamber vacuum level reaches a preset working chamber vacuum level, a signal to turn off the molecular pump is sent to the second control device. In response to the vacuum operation start command, a signal to turn on the first mechanical pump valve is sent to the second control device to perform a pre-vacuum operation on the pre-vacuum chamber containing the preset sample. The pre-vacuum level of the pre-vacuum chamber, collected by the first vacuum gauge, is obtained through the second control device. When the vacuum level reaches the preset pre-evacuation chamber vacuum level, a closing signal is sent to the second control device for the first mechanical pump valve to stop the pre-evacuation chamber vacuuming operation; an opening signal is sent to the second control device for the connecting valve; and a closing signal is sent to the second control device for the connecting valve after a preset connection time interval; an opening signal is sent to the second control device for the gate valve to connect the sample delivery track of the pre-evacuation chamber with the sample delivery track of the working chamber; after the preset sample moves to the working chamber, a closing signal is sent to the second control device for the gate valve.

[0005] Optionally, the vacuum control system further includes a third control device connected to the lithography machine cavity, in which a lithography machine is disposed. The first control device is configured to: after the preset sample moves to the working cavity and the gate valve closes, send an exposure request signal to the third control device to enable the third control device to control the lithography machine to expose the preset sample; upon receiving an exposure end command transmitted by the third control device, send an open signal to the second control device for the connecting valve, and after a preset connection time interval, send a closed signal to the second control device for the connecting valve; send an open signal to the second control device for the gate valve to move the exposed preset sample from the working cavity to the pre-extraction cavity; and send a closed signal to the second control device for the gate valve to disconnect the connection between the working cavity and the pre-extraction cavity.

[0006] Optionally, the vacuum control system further includes at least one image acquisition device and a display screen. Each image acquisition device is connected to the first control device and the display screen. At least one image acquisition device is disposed in the working chamber for capturing images of the chamber. The display screen is used to display the images of the chamber. The first control device is configured to control the device status of each image acquisition device.

[0007] Optionally, the device state of the image acquisition device includes a power-on state and a power-off state. The first control device is configured to: send a power-off control signal to the image acquisition device to switch to the power-off state before sending an exposure request signal to the third control device; and send a power-on control signal to the image acquisition device to switch to the power-on state after receiving an exposure end command transmitted by the third control device.

[0008] Optionally, the vacuum control system further includes a vent valve disposed between the pre-evacuation chamber and the second control device. The first control device is configured to: after disconnecting the connection between the working chamber and the pre-evacuation chamber, send an open signal to the second control device for the vent valve to perform a vacuum release operation on the pre-evacuation chamber; and when the open duration of the vent valve reaches a preset vacuum release duration, send a closed signal to the second control device for the vent valve to facilitate the removal of the exposed preset sample placed in the pre-evacuation chamber.

[0009] Optionally, the vacuum control system further includes a second mechanical pump valve, a gas storage tank, and a third vacuum gauge. One end of the molecular pump is connected to the working chamber and / or the lithography machine chamber, and the other end of the molecular pump is connected to one end of the gas storage tank. The other end of the gas storage tank is connected to the second mechanical pump valve, which is connected to the mechanical pump. The third vacuum gauge is connected to both the gas storage tank and the second control device. The first control device is configured to: acquire the gas storage tank vacuum level collected by the third vacuum gauge through the second control device; send an open signal to the second control device for the second mechanical pump valve when the gas storage tank vacuum level does not reach a preset gas storage tank vacuum level; and send a closed signal to the second control device for the second mechanical pump valve when the gas storage tank vacuum level reaches the preset gas storage tank vacuum level.

[0010] Optionally, the first control device is configured to: after the preset sample moves to the working chamber and the valve is closed, acquire the pre-vacuum level of the pre-vacuum chamber collected by the first vacuum gauge through the second control device; when the pre-vacuum level reaches the vacuum level of the mechanical pump, send a start signal for the mechanical pump to the second control device and send an open signal for the first mechanical pump valve to perform the pre-vacuum chamber vacuuming operation; when the pre-vacuum level reaches the preset pre-vacuum level, send a close signal for the first mechanical pump valve to the second control device to stop the pre-vacuum chamber vacuuming operation.

[0011] Optionally, the second control device includes a controller, a first step-down circuit, a second step-down circuit, a network communication circuit, a host computer communication circuit, a reset circuit, and a multi-channel relay. The input power supply is connected to one end of the first step-down circuit. The other end of the first step-down circuit is connected to one end of the network communication circuit and one end of the second step-down circuit. The other end of the second step-down circuit is connected to the power supply terminal of the controller. The other end of the network communication circuit is connected to the controller. The network port of the network communication circuit is used to connect to a vacuum gauge. The host computer communication circuit is located between the controller and the first control device. The reset circuit is connected to the reset pin of the controller. The multi-channel relay is located between the controller and multiple preset control valves. The multiple preset control valves include the gate valve, the first mechanical pump valve, the second mechanical pump valve, a connecting valve, and a vent valve. One of the multiple relays corresponds to one preset control valve.

[0012] Optionally, the controller is configured to determine the vacuum level detected by the vacuum gauge using the following formula:

[0013] in, This refers to the vacuum level detected by the vacuum gauge. This refers to the output voltage value of the vacuum gauge calculated by the controller based on the voltage value detected at the other end of the network communication circuit.

[0014] Optionally, the first control device includes a Raspberry Pi processor.

[0015] This application provides a vacuum control system for a lithography machine. The vacuum control system includes a pre-evacuation chamber, a working chamber, a lithography machine chamber, a gate valve, a first vacuum gauge, a connecting valve, a second vacuum gauge, a mechanical pump, a first mechanical pump valve, a molecular pump, a first control device, and a second control device. The working chamber is located between the pre-evacuation chamber and the lithography machine chamber. The gate valve is located between the sample delivery tracks corresponding to the working chamber and the pre-evacuation chamber. The mechanical pump is connected to the pre-evacuation chamber via the first mechanical pump valve, and the first vacuum gauge is connected to the pre-evacuation chamber. The connecting valve is located between the sample delivery tracks corresponding to the working chamber and the pre-evacuation chamber. A molecular pump is connected to the working chamber, and a second vacuum gauge is connected to the lithography machine chamber. The lithography machine chamber and the working chamber are interconnected. A second control device is connected to a first control device, a gate valve, a first vacuum gauge, a connecting valve, a second vacuum gauge, a mechanical pump, a molecular pump, and a first mechanical pump valve. The first control device is configured to: acquire the working chamber vacuum level of the working chamber collected by the second vacuum gauge in real time through the second control device; and when the working chamber vacuum level does not reach the preset working chamber vacuum level, send a signal to the second control device. The system is equipped with a control device to send an open signal to the molecular pump to perform a vacuum operation on the working chamber. When the working chamber vacuum reaches a preset working chamber vacuum level, it sends a close signal to the molecular pump. In response to the vacuum operation start command, it sends an open signal to the first mechanical pump valve to perform a pre-vacuum operation on the pre-vacuum chamber containing the preset sample. The system obtains the pre-vacuum chamber vacuum level collected by the first vacuum gauge through the second control device. When the pre-vacuum chamber vacuum level reaches the preset pre-vacuum chamber vacuum level, it sends a close signal to the first mechanical pump valve to stop the pre-vacuum operation. It also sends an open signal to the connecting valve and a close signal to the connecting valve after a preset connecting time interval. Finally, it sends an open signal to the gate valve to connect the sample delivery track of the pre-vacuum chamber with the sample delivery track of the working chamber. After the preset sample moves to the working chamber, it sends a close signal to the gate valve.This application addresses the issue of long vacuum times caused by frequent sample feeding and retrieval by placing the working chamber between the pre-evacuation chamber and the lithography machine chamber, and by setting a gate valve between them to control the connection. A mechanical pump and a first mechanical pump valve are used to perform vacuuming operations on the pre-evacuation chamber, while a molecular pump is used to perform vacuuming operations on the working chamber. This division of the overall vacuum chamber into a pre-evacuation chamber and a working chamber reduces vacuuming time. The pre-evacuation chamber, containing a pre-set sample, is vacuumed. After reaching the preset vacuum level, a connecting valve first connects the working chamber and the pre-evacuation chamber to balance the pressure. Then, a gate valve connects the working chamber and the pre-evacuation chamber to transfer the pre-set sample to the working chamber before closing the gate valve. This allows the working chamber to continuously approach the required preset working chamber vacuum level. By using a pre-evacuation chamber and a gate valve, the technical problem of long vacuuming times caused by frequent sample feeding and retrieval is solved, achieving the technical effect of reducing vacuuming time.

[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments 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.

[0018] Figure 1 This illustration shows a schematic diagram of a vacuum control system for a lithography machine provided in an embodiment of this application. Figure 1 .

[0019] Figure 2 A control flowchart of a vacuum control system for a lithography machine provided in an embodiment of this application is shown.

[0020] Figure 3 This illustration shows a schematic diagram of a vacuum control system for a lithography machine provided in an embodiment of this application. Figure 2 .

[0021] Figure 4 This illustration shows a schematic diagram of a vacuum control system for a lithography machine provided in an embodiment of this application. Figure 3 .

[0022] Figure 5 A schematic diagram of the vacuum curve of the gas storage tank and the vacuum curve of the pre-evacuation chamber provided in the embodiments of this application is shown. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0024] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0025] Currently, due to the large volume of the sample chamber, each vacuuming process takes a long time, often several hours, to reach the required vacuum level. This not only significantly reduces experimental efficiency but also increases system energy consumption and operating costs, especially in applications requiring frequent sample changes.

[0026] Existing electron beam lithography equipment typically relies on the coupled control of a mechanical pump, a molecular pump, and a vacuum gauge during vacuum evacuation and devastation processes, managed by a bulky dedicated controller. This structure results in large equipment size, complex layout, low integration of the control system, increased equipment cost and maintenance difficulty, and limited effective utilization of laboratory space. Furthermore, electron beam lithography vacuum control systems often use microcontrollers as the lower-level control core. Microcontrollers only possess limited real-time control capabilities, with limited processing performance and system scalability, and are insufficient in multi-cavity zone control, complex data interaction, and graphical interface support.

[0027] Furthermore, existing control systems generally suffer from poor coupling with host computer systems, hindering efficient data and command interaction and impeding intelligent and automated system control. Simultaneously, current equipment typically lacks real-time visualization support for the internal state of the vacuum chamber, preventing operators from intuitively understanding changes in the internal environment and increasing the difficulty and risk of operation.

[0028] In summary, existing electron beam lithography machines still suffer from the following shortcomings in their vacuum control systems: long vacuuming time, complex system structure, low integration with the host computer exposure software, low operating efficiency, high equipment cost, cumbersome operation, and a lack of real-time monitoring of the cavity status. These problems, to some extent, restrict further improvements in equipment performance and urgently require improvement.

[0029] Based on this, embodiments of this application provide a vacuum control system for a lithography machine. By placing the working chamber between the pre-evacuation chamber and the lithography machine cavity, and setting a gate valve between the working chamber and the pre-evacuation chamber to control whether the working chamber and the pre-evacuation chamber are connected, a mechanical pump and a first mechanical pump valve are used to perform a vacuuming operation on the pre-evacuation chamber, and a molecular pump is used to perform a vacuuming operation on the working chamber. Thus, splitting the overall vacuum chamber into a pre-evacuation chamber and a working chamber can reduce the vacuuming time. For the pre-evacuation chamber where a preset sample has been placed... The system performs a pre-evacuation operation in the pre-evacuation chamber. After the pre-evacuation chamber reaches the preset vacuum level, a connecting valve first connects the working chamber and the pre-evacuation chamber to balance the gas pressure. Then, a gate valve connects the working chamber and the pre-evacuation chamber to transfer the preset sample to the working chamber. Finally, the gate valve is closed. This allows the working chamber to be continuously controlled to approach the required preset working chamber vacuum level. By setting up the pre-evacuation chamber and gate valve, the technical problem of long vacuuming time caused by frequent sample delivery and retrieval is solved, achieving the technical effect of reducing vacuuming time, as detailed below: Please see Figure 1 , Figure 1 A schematic diagram of a vacuum control system for a lithography machine provided in this application embodiment. Figure 1 .like Figure 1 As shown, the vacuum control system of the lithography machine provided in this application embodiment includes a pre-evacuation chamber 101, a working chamber 102, a lithography machine chamber 103, a gate valve 104, a first vacuum gauge 1051, a connecting valve 1052, a mechanical pump 106, a first mechanical pump valve 107, a second mechanical pump valve 108, a vent valve 109, a molecular pump 110, a gas storage tank 111, a second vacuum gauge 112, a third vacuum gauge 113, a first control device (not shown in the figure), and a second control device (not shown in the figure).

[0030] The working chamber is located between the pre-evacuation chamber and the lithography machine chamber, and the gate valve is located between the sample delivery tracks corresponding to the working chamber and the pre-evacuation chamber, respectively. The lithography machine chamber needs to generate and accelerate the electron beam. The working chamber serves as the area for sample exposure and processing. The pre-evacuation chamber is connected to the working chamber via the gate valve, allowing for pre-vacuuming before the sample enters the working chamber.

[0031] In other words, the working chamber is connected to the lithography machine chamber so that the lithography machine in the lithography machine chamber can irradiate the preset sample in the working chamber, facilitating the exposure process of the preset sample. The working chamber is connected to the pre-extraction chamber via a gate valve. The gate valve controls whether the working chamber is connected to the pre-extraction chamber, or in other words, whether the sample feed track of the working chamber is connected to the sample feed track of the pre-extraction chamber. When the gate valve is open, the sample feed track of the working chamber is connected to the sample feed track of the pre-extraction chamber, and the working chamber and the pre-extraction chamber are connected; when the gate valve is closed, the connection between the sample feed track of the working chamber and the sample feed track of the pre-extraction chamber is severed, and the working chamber and the pre-extraction chamber are not connected.

[0032] For example, the valve can be configured to control whether the working chamber is connected to the pre-extraction chamber by pushing or pulling. Pushing the valve aligns the through-hole on the valve with the sample delivery track of the working chamber and the sample delivery track of the pre-extraction chamber, thus connecting the working chamber and the pre-extraction chamber. Pushing the valve also prevents the through-hole from contacting either the sample delivery track of the working chamber or the sample delivery track of the pre-extraction chamber, thus preventing communication between the two chambers. The valve is further isolated from the pre-extraction chamber by other parts besides the through-hole, ensuring that both the working chamber and the pre-extraction chamber are independent, sealed chambers.

[0033] Specifically, the mechanical pump is connected to the pre-evacuation chamber via the first mechanical pump valve, the first vacuum gauge is connected to the pre-evacuation chamber, the connecting valve is disposed between the pre-evacuation chamber and the working chamber, the molecular pump is connected to the working chamber, the second vacuum gauge is connected to the lithography machine chamber, the lithography machine chamber is in communication with the working chamber, and the second control device is connected to the first control device, the gate valve, the first vacuum gauge, the connecting valve, the second vacuum gauge, the mechanical pump, the molecular pump, and the first mechanical pump valve.

[0034] In other words, the control of whether the mechanical pump performs a vacuum operation on the pre-evacuation chamber is achieved by controlling the opening and closing of the first mechanical pump valve. When the mechanical pump starts evacuating, if the first mechanical pump valve is open, the mechanical pump and the pre-evacuation chamber are connected, and the mechanical pump can perform a vacuum operation on the pre-evacuation chamber. If the first mechanical pump valve is closed, the mechanical pump and the pre-evacuation chamber are not connected, and the mechanical pump cannot perform a vacuum operation on the pre-evacuation chamber.

[0035] The system employs a first vacuum gauge connected to the pre-evacuation chamber to detect its vacuum level. A second vacuum gauge connects to the lithography machine chamber, and since the lithography machine chamber is connected to the working chamber, the vacuum level detected by the second vacuum gauge represents both the vacuum level of the lithography machine chamber and the vacuum level of the working chamber. A connecting valve between the pre-evacuation chamber and the working chamber connects them. When the connecting valve is open, gas exchange occurs between the pre-evacuation chamber and the working chamber to equalize the gas pressure. When the connecting valve is closed, gas exchange and pressure equalization between the pre-evacuation chamber and the working chamber are impossible. A molecular pump is used to extract gas from the working chamber.

[0036] The second control device is connected to the first control device, the gate valve, the first vacuum gauge, the connecting valve, the second vacuum gauge, the mechanical pump, the molecular pump, the first mechanical pump valve, and the second mechanical pump valve. Furthermore, the first control device, through the second control device, controls the opening and closing of the gate valve, the first mechanical pump valve, the second mechanical pump valve, and the connecting valve; it also controls the operation and shutdown of the mechanical pump and the molecular pump; and it controls the vacuum detection device to collect the vacuum level of the pre-evacuation chamber or the working chamber. The first control device receives from the second control device the actual opening and closing status of the gate valve, the connecting valve, the first mechanical pump valve, and the second mechanical pump valve, as well as the vacuum level collected by the vacuum detection device.

[0037] For example, the first control device includes a Raspberry Pi processor, which includes a Raspberry Pi 5. The Raspberry Pi 5 is a processor based on the Linux kernel and the Ubuntu operating system, and has stronger processing performance, richer interface resources, and a complete software ecosystem.

[0038] The first control device is configured to: acquire the working chamber vacuum degree of the working chamber collected by the second vacuum gauge in real time through the second control device; when the working chamber vacuum degree does not reach the preset working chamber vacuum degree, send an open signal for the molecular pump to the second control device to perform a working chamber evacuation operation; and when the working chamber vacuum degree reaches the preset working chamber vacuum degree, send a close signal for the molecular pump to the second control device.

[0039] In other words, after the system is powered on, the working chamber for lithography needs to be kept in a near-vacuum state because the lithography process requires a near-vacuum state. Therefore, after the system is powered on, the vacuum level of the working chamber can be used to directly perform a vacuuming operation on the working chamber, thereby reducing waiting time and shortening the vacuuming process. Thus, after the system is powered on, the second vacuum gauge begins to collect the working chamber vacuum level in real time, and the second control device sends the working chamber vacuum level to the first control device. The first control device compares the working chamber vacuum level with a preset working chamber vacuum level. If the working chamber vacuum level is greater than the preset working chamber vacuum level, it sends an open signal to the second control device to start the molecular pump and perform a vacuuming operation on the working chamber and the lithography machine cavity. If the working chamber vacuum level is less than or equal to the preset working chamber vacuum level, it sends a close signal to the second control device to stop the vacuuming operation on the working chamber and the lithography machine cavity.

[0040] The first control device is configured to: in response to a vacuuming operation start command, send an open signal to the second control device for the first mechanical pump valve to perform a pre-vacuuming operation on the pre-vacuuming chamber where a preset sample has been placed; acquire the pre-vacuuming chamber vacuum level collected by the vacuum detection device through the second control device; when the pre-vacuuming chamber vacuum level reaches a preset pre-vacuuming chamber vacuum level, send a close signal to the second control device for the first mechanical pump valve to stop the pre-vacuuming operation; send an open signal to the second control device for the connecting valve, and send a close signal to the second control device for the connecting valve after a preset connecting time interval; send an open signal to the second control device for the gate valve to connect the sample delivery track of the pre-vacuuming chamber with the sample delivery track of the working chamber; and after the preset sample moves to the working chamber, send a close signal to the second control device for the gate valve.

[0041] For example, the start command for the vacuuming operation can be issued actively by the operator. This can be achieved by setting a start button connected to a first control device. After the operator places the preset sample in the pre-vacuum chamber, they press the start button, and the first control device receives the start command for the vacuuming operation. Alternatively, the start command for the vacuuming operation can be issued by the operator clicking the start control on the corresponding control page of the Raspberry Pi. This application does not impose any limitations on this method.

[0042] For example, please refer to Figure 2 , Figure 2 This is a control flowchart of a vacuum control system for a lithography machine provided in an embodiment of this application. Figure 2As shown, the operator places a preset sample onto the sample stage, which can move along the sample delivery tracks of the pre-evacuation chamber and the working chamber. Then, the operator triggers the start control corresponding to the vacuuming operation on the control page. The first control device receives the start command for the vacuuming operation and sends a command to the third control device to start the image acquisition device in the working chamber, i.e., to start and initialize the image acquisition device. The first control device sends an open signal to the second control device and a closed signal to the second mechanical pump valve to ensure that the mechanical pump starts working but cannot evacuate the working chamber. After waiting for a first preset time period (which can be set to 1 second), the first control device sends an open signal to the second control device to control the first mechanical pump valve to open it, allowing the pre-evacuation operation to be performed only on the pre-evacuation chamber. While the first mechanical pump valve is open, it continuously checks whether to proceed to the next operation within 15 minutes. If no further operation is performed within 15 minutes, the process resets and returns to the starting point. After determining that the mechanical pump cannot extract gas from the gas storage tank through the second mechanical pump valve when the second mechanical pump valve is closed, the first mechanical pump valve is then opened so that the mechanical pump can extract air from the pre-evacuation chamber through the first mechanical pump valve.

[0043] Furthermore, during the pre-evacuation operation of the pre-evacuation chamber, the second control device will acquire the pre-evacuation chamber vacuum degree collected by the vacuum detection device in real time and send the pre-evacuation chamber vacuum degree to the first control device. When the first control device determines that the pre-evacuation chamber vacuum degree has reached the preset pre-evacuation chamber vacuum degree, it means that the vacuum degree of the pre-evacuation chamber is close to the vacuum state, and it is considered that the pre-evacuation chamber and the working chamber can be connected at this time. When the pre-evacuation chamber vacuum reaches the preset pre-evacuation chamber vacuum level, a prompt signal corresponding to the preset pre-evacuation chamber vacuum level is displayed on the control page. The operator then triggers the sample delivery control on the control page, sending a sample delivery command to the third control device. The third control device then identifies whether the lithography machine's pattern generator is in place. If the pattern generator is not in place, the third control device sends a "not in place" signal to the first control device, prompting the first control device to re-display the sample delivery control on the control page. If the pattern generator is in place, the third control device sends a power-on control signal to the first control device for the image acquisition device, thus activating the image acquisition device and displaying the chamber image captured by the image acquisition device on the control page. Therefore, the first control device sends a closing signal to the second control device for the first mechanical pump valve to stop the pre-evacuation operation of the chamber, and sends an opening signal to the second control device for the connecting valve to connect the gas in the working chamber and the pre-evacuation chamber. This avoids sudden pressure changes in the working chamber due to the pressure difference between the working chamber and the pre-evacuation chamber when the valve is opened, reducing the impact of pressure changes on the equipment in the working chamber. After a preset connection time period after the connecting valve is opened, a closing signal is sent to the second control device for the connecting valve to cut off the connection between the working chamber and the pre-evacuation chamber. After waiting for a second preset time period (which can be set to 1 second), an opening signal is sent to the second control device for the valve, thereby aligning the sample delivery track of the pre-evacuation chamber with the sample delivery track of the working chamber, so that the sample can move from the sample delivery track of the pre-evacuation chamber to the sample delivery track of the working chamber, and then move to the working chamber to complete the sample delivery. The operator can visually observe that the preset sample has moved from the sample delivery track of the pre-extraction chamber to the sample delivery track of the working chamber. The operator can then click the sample delivery control on the control page again to confirm that the sample delivery has been completed. At this point, the first control device can start detecting whether the sample stage has moved into place.

[0044] For example, after the preset sample is moved to the working chamber, it can be confirmed whether the sample stage carrying the sample has moved to a preset position in the working chamber. This preset position refers to the position where the lithography machine in the lithography chamber can perform lithography processing. That is, the sample stage can move on the sample feed track of the pre-extraction chamber and the sample feed track of the working chamber. Thus, by moving the sample stage, the preset sample placed on the sample stage can be moved from the pre-extraction chamber to the working chamber. The sample stage can be configured as a device that requires operator intervention to move, thereby moving the preset sample. Furthermore, after the preset sample moves to the working chamber, a closing signal for the gate valve is sent to the second control device to isolate the working chamber and the pre-extraction chamber.

[0045] Specifically, the first control device is configured to: after the preset sample moves to the working chamber and the valve is closed, acquire the pre-vacuum level of the pre-vacuum chamber collected by the first vacuum gauge through the second control device; when the pre-vacuum level reaches the vacuum level of the mechanical pump, send a start signal for the mechanical pump to the second control device and send an open signal for the first mechanical pump valve to perform the pre-vacuum chamber vacuuming operation; when the pre-vacuum level reaches the preset pre-vacuum level, send a close signal for the first mechanical pump valve to the second control device to stop the pre-vacuum chamber vacuuming operation and send a stop signal for the mechanical pump.

[0046] Specifically, the vacuum control system further includes at least one image acquisition device and a display screen. Each image acquisition device is connected to the first control device and the display screen. At least one image acquisition device is disposed in the working cavity for capturing images of the cavity. The display screen is used to display the images of the cavity. The first control device is configured to control the device status of each image acquisition device.

[0047] For example, the display screen can show the Raspberry Pi's control page. The device status of the image acquisition device includes a power-on state and a power-off state. The power-on state refers to the state where the image acquisition device begins capturing images of the cavity, and the power-off state refers to the state where the image acquisition device stops capturing images of the cavity. The image acquisition device can be configured as a camera or an industrial camera (CCD). If the camera is installed in the working cavity, it captures images of the cavity, which are then uploaded to the display screen for monitoring the vacuuming operation.

[0048] For example, after the sample moves to the working chamber and the valve closes for 1 second, the first control device sends a power-off control signal to the image acquisition device, and the pop-up window displaying the chamber image on the control page exits, at which point the pre-vacuum detection mode is entered. The second control device acquires the pre-vacuum chamber vacuum level collected by the first vacuum gauge. When the pre-vacuum chamber vacuum level reaches the vacuum level of the mechanical pump, a start signal for the mechanical pump is sent to the second control device to start the mechanical pump. After 0.5 seconds, an open signal for the first mechanical pump valve is sent to the second control device to perform the pre-vacuum chamber vacuum operation. When the pre-vacuum chamber vacuum level reaches the preset pre-vacuum chamber vacuum level, a close signal for the first mechanical pump valve is sent to the second control device to stop the pre-vacuum chamber vacuum operation. After 0.5 seconds of the first mechanical pump valve closing, a close signal is sent to the mechanical pump through the second control device to stop the mechanical pump from working. Alternatively, in the pre-evacuation detection mode, as long as the first vacuum gauge determines that the vacuum degree of the pre-evacuation chamber has not reached the preset pre-evacuation chamber vacuum degree, an opening signal for the first mechanical pump valve is sent to the second control device to perform a pre-evacuation chamber vacuuming operation. In other words, it is not necessary to determine whether the vacuum degree of the pre-evacuation chamber has reached the vacuum degree of the mechanical pump. As long as the vacuum degree of the pre-evacuation chamber has not reached the preset pre-evacuation chamber vacuum degree, the pre-evacuation chamber vacuuming operation is performed on the pre-evacuation chamber. When the vacuum degree of the pre-evacuation chamber reaches the preset pre-evacuation chamber vacuum degree, the pre-evacuation chamber vacuuming operation is stopped.

[0049] Furthermore, a valve separates the pre-evacuation chamber and the working chamber. When the preset sample is introduced into the pre-evacuation chamber from the outside, the valve remains closed. This ensures that the process of placing the preset sample only affects the vacuum level of the pre-evacuation chamber. After the preset sample is placed in the pre-evacuation chamber, a pre-evacuation vacuuming operation is performed to ensure the vacuum level reaches the ideal level required for exposure processing. Then, a connecting valve and a gate valve connect the pre-evacuation chamber and the working chamber. Thus, after the preset sample is introduced into the working chamber through the open gate valve and then the gate valve is closed, the vacuum level of the working chamber is measured using a second vacuum gauge. If the working chamber vacuum level does not reach the preset working chamber vacuum level, a working chamber vacuuming operation is performed to control the working chamber at the vacuum level required for exposure processing.

[0050] In other words, the air pressure between the pre-extraction chamber and the working chamber is balanced in advance by using a connecting valve. Before the gate valve is opened, the air pressure between the pre-extraction chamber and the working chamber is balanced by the connecting valve. Then the gate valve is opened to move the preset sample from the pre-extraction chamber to the working chamber. Since the sample delivery stage is short and the air pressure between the pre-extraction chamber and the working chamber is balanced in advance by using the connecting valve, the air pressure difference between the pre-extraction chamber and the working chamber is maintained in a smooth stage. After the gate valve is opened, the air pressure difference will not cause the gas in the pre-extraction chamber to suddenly rush into the working chamber, thus preventing the air pressure in the working chamber from rising.

[0051] For example, the preset pre-evacuation chamber vacuum degree and the preset working chamber vacuum degree are equal, both set to 8 Pa. The vacuum degree of the mechanical pump can be set to 200 Pa. This application does not limit this.

[0052] Furthermore, since the valve is closed each time a preset sample is sent into the pre-evacuation chamber, it does not affect the vacuum level of the working chamber. Before opening the valve to move the pre-evacuation chamber to the working chamber, the pre-evacuation chamber needs to be evacuated to reduce the vacuum difference between the two chambers. This maintains the working chamber at a vacuum level close to that required for exposure processing, thus reducing the time required for evacuating the working chamber. Also, since only the vacuum level of the pre-evacuation chamber changes each time a preset sample is sent into or removed from it, without altering the working chamber's vacuum level, this effectively splits the sample chamber in the prior art into a pre-evacuation chamber and a working chamber that can independently perform evacuation operations. Compared to the sample chamber in the prior art, this reduces the space of the pre-evacuation chamber and the time required for evacuation, thereby reducing the overall evacuation time.

[0053] Specifically, the vacuum control system further includes a third control device connected to the lithography machine cavity, in which the lithography machine is housed. In other words, the third control device is used to control the lithography machine within the lithography machine cavity.

[0054] The first control device is configured to: after the preset sample moves to the working chamber and the gate valve closes, send an exposure request signal to the third control device so that the third control device controls the lithography machine to expose the preset sample; upon receiving an exposure end command transmitted by the third control device, send an open signal to the second control device for the connecting valve, and after a preset connecting time interval, send a closed signal to the second control device for the connecting valve; send an open signal to the second control device for the gate valve so that the exposed preset sample moves from the working chamber to the pre-extraction chamber; and send a closed signal to the second control device for the gate valve to disconnect the connection between the working chamber and the pre-extraction chamber.

[0055] In other words, after the preset sample is moved to the working chamber and the gate valve is closed, the exposure process and the pre-sampling detection mode can be performed simultaneously, or the pre-sampling detection mode can be entered first and then the exposure process can be performed, or the exposure process can be performed first and then the pre-sampling detection mode can be entered. The simultaneous execution can reduce the time cost.

[0056] In other words, when it is determined that exposure processing is required on a preset sample, an exposure request signal needs to be sent to the third control device. Before actual exposure processing, it is also necessary to confirm whether the photomask and the preset sample are aligned to ensure accurate transfer of the pattern on the photomask onto the preset sample. Furthermore, before sending the exposure request signal to the third control device, an exposure condition judgment command needs to be sent. Upon receiving the exposure condition judgment command, the third control device confirms whether the pattern generator is in place, i.e., whether the photomask corresponds to the preset sample. If the pattern generator is not in place, the third control device sends an exposure condition unconfirmed command to the first control device to stop exposure and can also send a prompt message for the operator to check the status of the lithography machine. Once the pattern generator is confirmed to be in place, the third control device sends an exposure condition confirmation command to the first control device. Upon receiving the exposure condition confirmation command, the first control device then sends an exposure request signal to the third control device, enabling the third control device to control the lithography machine to expose the preset sample.

[0057] Specifically, the first control device is configured to: send a power-off control signal to the image acquisition device to switch to the power-off state before sending an exposure request signal to the third control device; and send a power-on control signal to the image acquisition device to switch to the power-on state after receiving an exposure end command transmitted by the third control device.

[0058] In other words, it is necessary to ensure that the image acquisition device is switched to a power-off state before entering the exposure process to prevent the light emitted by the image acquisition device from affecting the normal operation of the lithography machine. After exposure is completed, the image acquisition device can be switched to a power-on state to turn on the image acquisition device and display the cavity image captured by the image acquisition device on the display screen.

[0059] Subsequently, after the preset sample moves to the working chamber and the valve closes, the first control device sends an exposure request signal to the third control device, thereby the third control device starts the lithography machine to run the exposure software to expose the preset sample. After the exposure process, the third control device sends an exposure end command to the first control device to inform the first control device that the exposure process has been completed and the exposed preset sample can be taken out.

[0060] like Figure 2 As shown, after the exposure process, the third control device sends an exposure end command to the first control device. Upon receiving the exposure end command, the first control device displays a sampling control on its control page. The operator triggers the sampling control, informing the first control device that it has entered the sampling start step. Then, the first control device sends a sampling command to the third control device to determine whether the lithography machine's pattern generator is in place, thus determining whether the lithography machine is not working. If the pattern generator is not in place, and the lithography machine is determined to be not working, the third control device sends an exposure end command to the first control device. The first control device then sends a power-on control signal to the image acquisition device, causing the image acquisition device to start capturing the cavity image and displaying a cavity image pop-up window on the control page. Furthermore, the first control device sends a closing signal to the second control device for the first mechanical pump valve to prevent vacuuming of the pre-evacuation cavity during the sampling process.

[0061] Then, the first control device sends an open signal to the second control device for the gate valve to reconnect the working chamber and the pre-extraction chamber. This allows the worktable in the working chamber to move from the sample delivery track in the working chamber to the sample delivery track in the pre-extraction chamber. The sample track is manually moved to move the exposed sample carried by the worktable in the working chamber to the pre-extraction chamber. Before opening the gate valve, the first control device sends an open signal to the second control device for the connecting valve, and after a preset connection time interval, sends a closing signal to the connecting valve to the second control device. This balances the working chamber and the pre-extraction chamber before opening the gate valve.

[0062] Subsequently, after the valve opens, the exposed sample moves from the working chamber to the pre-extraction chamber. The operator presses the sampling button on the control panel again to inform the first control device that sampling has been completed and to confirm whether the sample stage has been pushed into place, i.e., whether it has moved to the designated position in the pre-extraction chamber. Upon confirming that the sample stage has moved to the designated position in the pre-extraction chamber, a closing signal is sent to the image acquisition device to close the valve, thereby cutting off the connection between the working chamber and the pre-extraction chamber. A power-off control signal is also sent to the image acquisition device to switch it to a power-off state. The image acquisition device stops capturing images of the chamber, and the chamber image pop-up on the control panel disappears, no longer displaying the chamber image.

[0063] like Figure 1 As shown, the vent valve is disposed between the pre-evacuation chamber and the second control device. The first control device is configured to: after disconnecting the connection between the working chamber and the pre-evacuation chamber, send an open signal to the second control device for the vent valve to perform a vacuum release operation on the pre-evacuation chamber; and when the open duration of the vent valve reaches a preset vacuum release duration, send a closed signal to the second control device for the vent valve to facilitate the removal of the exposed preset sample placed in the pre-evacuation chamber.

[0064] In other words, such as Figure 2 As shown, after the exposure process, when the preset sample has been moved to the pre-evacuation chamber and the image acquisition device has been switched to the power-off state, the vacuum release step is initiated. The system checks whether the valve is closed. After confirming the valve is closed and disconnecting the connection between the working chamber and the pre-evacuation chamber, the first control device sends an opening signal to the second control device for the vent valve. This opens the vent valve to facilitate the vacuum release operation in the pre-evacuation chamber. When the vent valve remains open for the preset vacuum release time, the vacuum release operation is complete. At this point, the operator can open the pre-evacuation chamber and remove the exposed preset sample, thus transforming the unexposed preset sample into an exposed preset sample. The exposed preset sample can then proceed to subsequent processing steps.

[0065] like Figure 1 As shown, one end of the molecular pump is connected to the working chamber and / or the lithography machine chamber, the other end of the molecular pump is connected to one end of the gas storage tank, the other end of the gas storage tank is connected to the second mechanical pump valve, the second mechanical pump valve is connected to the mechanical pump, and the third vacuum gauge is connected to the gas storage tank and the second control device.

[0066] The working chamber and the lithography machine chamber are connected, so the molecular pump can be connected to only one of the working chamber and the lithography machine chamber, or the molecular pump can be directly connected to the working chamber and the lithography machine chamber, thereby extracting gas from the working chamber and the lithography machine chamber through the molecular pump.

[0067] The first control device is configured to: acquire the vacuum degree of the gas storage tank collected by the third vacuum gauge through the second control device; when the vacuum degree of the gas storage tank does not reach the preset vacuum degree, send an open signal for the second mechanical pump valve to the second control device; and when the vacuum degree of the gas storage tank reaches the preset vacuum degree, send a closed signal for the second mechanical pump valve to the second control device.

[0068] In other words, a high vacuum is further achieved by evacuating the working chamber and the lithography machine chamber using a molecular pump. The extracted gas is then discharged into a gas storage tank, which, in conjunction with a second mechanical pump valve, stabilizes the evacuation efficiency. The mechanical pump, through the second mechanical pump valve, performs the evacuation operation on the gas storage tank. Consequently, the vacuum control system effectively maintains the stability and exposure accuracy of the electron beam and shortens the chamber vacuum recovery time, thus achieving efficient and stable electron beam lithography processing.

[0069] Furthermore, in order to improve the vacuum level, a molecular pump and a gas storage tank are installed in the passage between the second mechanical pump valve and the working chamber. The working chamber vacuum level is controlled by the molecular pump, and the vacuum level of the gas storage tank is controlled by the mechanical pump and the second mechanical pump valve. The vacuum level can only be controlled at the level of 100 Pa by the mechanical pump and the second mechanical pump valve alone, while starting the molecular pump can control the vacuum level at the level of 10 Pa, thereby increasing the vacuum level of the working chamber by an order of magnitude and bringing the working chamber vacuum level as close to a vacuum state as possible.

[0070] Specifically, the second control device includes a controller, a first step-down circuit, a second step-down circuit, a network communication circuit, a host computer communication circuit, a reset circuit, and a multi-channel relay. The 24V input power supply is connected to one end of the first step-down circuit. The other end of the first step-down circuit is connected to one end of the network communication circuit and one end of the second step-down circuit. The other end of the second step-down circuit is connected to the power supply terminal of the controller. The other end of the network communication circuit is connected to the controller, and the network port of the network communication circuit is used to connect a vacuum gauge. The host computer communication circuit is located between the controller and the first control device. The reset circuit is connected to the reset pin of the controller. The multi-channel relay is located between the controller and multiple preset control valves, including the gate valve, the first mechanical pump valve, the second mechanical pump valve, a connecting valve, and a vent valve. One of the multi-channel relays corresponds to one preset control valve.

[0071] In other words, the first step-down circuit reduces the input power of 24V to 5V, and the second step-down circuit further reduces the 5V voltage to the 3.3V voltage required for the controller to operate. The 24V input power also directly supplies power to the network communication circuit, which includes a network port and a voltage divider circuit. The vacuum gauge is connected to the network port to obtain the 24V input power for operation. The vacuum gauge provides an output voltage to the network port, which is connected to one end of the voltage divider circuit. The other end of the voltage divider circuit serves as the other end of the network communication circuit, connecting to the controller. Thus, the controller first calculates the output voltage value directly output from the vacuum gauge to the network port by acquiring the voltage value at the other end of the network communication circuit and the circuit structure of the voltage divider circuit, and then calculates the vacuum level of the environment where the vacuum gauge is located based on the output voltage value.

[0072] In this system, the gate valve, the first mechanical pump valve, the second mechanical pump valve, the connecting valve, and the vent valve are each connected to the controller's input / output pins (I / O pins) via a corresponding relay from a multi-channel relay. The controller then transmits the control signals for opening or closing these valves—the gate valve, the first mechanical pump valve, the second mechanical pump valve, the connecting valve, and the vent valve—from their respective relays to the corresponding preset control valves, thereby controlling the opening or closing of these valves. For example, the gate valve is a solenoid valve, while the connecting valve, the vent valve, and the mechanical pump valve are all pneumatic valves.

[0073] Specifically, the controller is configured to determine the vacuum level detected by the vacuum gauge using the following formula: (1) In formula (1), This refers to the vacuum level detected by the vacuum gauge, measured in Pa. This refers to the output voltage value of the vacuum gauge calculated by the controller based on the voltage value detected at the other end of the network communication circuit.

[0074] For example, the vacuum gauge used in this application is model WRG200. The power supply voltage range of this vacuum gauge is 15 to 48V, and the maximum power consumption does not exceed 4W. Its output signal changes logarithmically with pressure, and the standard voltage output range is 2.0V to 10.0V. In order to achieve matching with the controller, the network communication circuit needs to reduce the output voltage value of the vacuum gauge to a voltage range of no more than 3.3V acceptable to the controller through a voltage divider circuit (including high-precision voltage divider resistors), and use a 12-bit ADC (analog-to-digital converter) to collect the voltage signal. The vacuum level of the environment where the vacuum gauge is located can be calculated by formula (1). Furthermore, if the output voltage of the vacuum gauge is at a specific abnormal value (such as 0.90V indicating an error, 1.30V indicating a breakdown failure), the controller can determine that the vacuum gauge is faulty and send an alarm message to the host computer to ensure the safety and reliability of the system operation.

[0075] The controller and the first control device communicate via a host computer communication circuit. A reset circuit includes a selectable reset button, which can be pressed to reset the program in case of an abnormal freeze. Multiple relays are used to redirect the controller's output signals to the corresponding preset control valves, facilitating the opening and closing of each valve.

[0076] For example, the first step-down circuit is a BUCK step-down circuit, the second step-down circuit is an LDO step-down circuit, and the controller model is an STM32F103RCT6 main control chip. The second control device also includes a start-up mode selection circuit, a program download header, a magnetic switch, and a limit switch. The startup mode selection circuit is connected to the controller's mode pin. This circuit grounds the mode pin, enabling the controller to enter the main flash memory startup mode. The controller's program download pin connects to a program download header to complete program download and debugging within the controller. A magnetic switch is connected to the controller's input / output (I / O) pins. The magnetic switch is set at the valve position to detect the valve's on / off state, i.e., whether the valve is open or closed. The controller uses the magnetic switch to determine whether the valve is open or closed. Limit switches are connected to the controller's input / output (I / O) pins. One limit switch is set on the sample delivery track of the working chamber to detect whether the sample delivery stage is in place when the sample delivery stage delivers the preset sample into the working chamber. The other limit switch is set on the sample delivery track of the preset chamber to detect whether the exposed preset sample is delivered into the preset chamber. Both the limit switches and the magnetic switch are connected to the controller via multiplex relays to send switching signals to the controller, thus providing isolation.

[0077] For example, the second control device further includes a molecular pump control circuit, which is located between the controller and the molecular pump to transmit open and close signals to the molecular pump. The molecular pump control circuit is directly connected to a 24V input power supply for power-on. The molecular pump control circuit includes a DB15 interface (DB, D-type data interface connector) and a cold start header. The DB15 interface is used to connect to the molecular pump to enable signal transmission between the molecular pump control circuit and the molecular pump, and the cold start header is used to perform a cold start on the molecular pump.

[0078] For example, the second control device also includes a lower-level screen, which is powered by a 5V power supply output from the first step-down circuit, and the lower-level screen interacts with the controller via a 4P socket.

[0079] For example, the second control device also includes a signal transmission terminal block, through which the controller and the multiplexer are connected for signal transmission.

[0080] Please see Figure 3 , Figure 3 A schematic diagram of a vacuum control system for a lithography machine provided in this application embodiment. Figure 2 .like Figure 3 As shown, the Raspberry Pi processor 201 acts as the host computer, running the operating system and applications to perform data processing, logic control, and remote communication functions. The STM32 microcontroller 202 (i.e., the controller in the second control device) acts as the slave computer, acquiring sensor signals, executing fast control commands, and communicating and cooperating with the Raspberry Pi 5. The multiplexer 203 receives control signals from the STM32 microcontroller to control the on / off state of external loads and provides electrical isolation. The switching power supply 204 inputs AC power and outputs a stable DC voltage to power the Raspberry Pi processor, STM32 microcontroller, and multiplexer. The terminal block 205 is used for wiring external sensors and actuators, ensuring stable and reliable electrical connections. The base plate 206 serves as a mounting base to fix the above modules, forming a compact integrated structure. Through the above design, an integrated solution for computation control, signal acquisition, load driving, and electrical isolation is achieved.

[0081] Please see Figure 4 , Figure 4 A schematic diagram of a vacuum control system for a lithography machine provided in this application embodiment. Figure 3 .like Figure 4As shown, the 220VAC-24VDC switching power supply converts the input 220V AC power into 24V DC power and inputs it to the terminal block. The terminal block provides a stable 24V input power to subsequent devices. The terminal block connects to one end of the first step-down circuit 301, the other end of which connects to one end of the second step-down circuit 302. The other end of the second step-down circuit 302 connects to the power supply terminal of the STM32 controller to supply power to the STM32. Vacuum gauges are connected to the STM32 controller via Ethernet communication circuit 303, with one vacuum gauge corresponding to one Ethernet communication circuit 303, allowing the controller to determine the vacuum level of the environment where each vacuum gauge is located. The STM32 controller is also connected to a Raspberry Pi 5 via a host computer communication circuit 304 to enable interaction between the first and second control devices. The STM32 controller also connects to various preset control valves via multiplex relays 305 to control the opening or closing of each preset control valve.

[0082] For example, the third control device can be an electronic device such as a Windows computer, mobile phone, or smartwatch. Then, by writing the exposure software into the processor of this electronic device, the graphic processing and process flow management required for photolithography can be achieved. Specifically, the exposure software implements unified scheduling of vacuum state control, sample transfer operations, and electron beam emission parameters. It also parses and processes the input graphic design files, converting CAD graphics into control instructions required for electron beam exposure. Furthermore, it provides exposure parameter settings, including beam current intensity, step spacing, and exposure time, and has error correction functions to correct electron beam deviation and field distortion. Through a human-machine interface, it supports sample loading control, process flow setting, and operational status monitoring, and stores and manages operational data. It also controls the sample loading and unloading enable of the control software.

[0083] For example, the third control device interacts with the first control device via serial communication. The first control device, as the system core, is responsible for issuing commands, relaying data, and acquiring images. The controller of the second control device interacts with the first control device via serial communication and connects to sensors such as magnetic switches, limit switches, and vacuum gauges. It also drives actuators such as mechanical pumps, valves, and vent valves through multiple relays to achieve precise control of the vacuum system. Through the coordinated operation of the above hardware and software, the system can complete automated control and status monitoring, ensuring the stability of the photolithography process and improving the reliability and efficiency of equipment operation.

[0084] Furthermore, the communication protocol between the third control device and the first control device is serial communication, and Table 1 is the protocol specification table for serial communication.

[0085] Table 1:

[0086] Furthermore, the controllers of the first and second control devices communicate via serial port, as detailed below: The STM32 microcontroller is responsible for sending the vacuum gauge's detection data to the first control device, where system status data is transmitted in string format. Corresponding identifiers are added to the headers of the data frames for the first, second, and third vacuum gauges, allowing the first control device to distinguish which gauge is collecting the vacuum level, thus enabling differentiation and parsing of different data sources. Correspondingly, when issuing control commands, the first control device adds a header identifier to the header of the command frame and an end-of-frame marker to the tail, before transmitting the command to the STM32 controller via serial port, thereby achieving effective system control and bidirectional communication.

[0087] For example, the Raspberry Pi can construct a vacuum curve from the vacuum levels collected in real time by various vacuum gauges. Please refer to [link / reference]. Figure 5 , Figure 5 This is a schematic diagram of the vacuum curve of the gas storage tank and the vacuum curve of the pre-evacuation chamber provided in the embodiments of this application. Figure 5 As shown, the horizontal axis represents time T (in seconds), and the vertical axis represents vacuum level p (in Pa). The black curve represents the vacuum level curve of the gas storage tank, and the red curve represents the vacuum level curve of the pre-evacuation chamber. The vacuum level of the gas storage tank stabilizes at approximately... The vacuum level is in the Pa range. With the initiation of the vacuuming operation, the vacuum level in the pre-evacuation chamber reaches a stable state of 8 Pa in approximately one and a half minutes, thus meeting the sample delivery conditions. Compared to traditional control schemes, this invention eliminates the need for a molecular pump and its control components in the pre-evacuation chamber, effectively reducing vacuuming costs.

[0088] The first control device is responsible for unified data interaction and centralized system management, primarily undertaking data transfer and control functions. It can plot vacuum curves from the real-time vacuum readings collected by each vacuum gauge and display these curves on its connected screen. This allows operators to intuitively monitor the vacuum levels of each gauge's environment and the overall system operating status, enabling remote monitoring without on-site supervision, reducing manual intervention and operational errors. It also supports flexible switching between automatic and manual modes, and can configure and manage serial port parameters, as well as perform reconnection after disconnection.

[0089] Furthermore, this application achieves parallel control of partitioned vacuuming of the pre-evacuation chamber and working chamber (i.e., simultaneous opening of the first and second mechanical pump valves) and real-time data processing through a vacuum control system, supporting a graphical interface and high-speed network communication, thereby improving the system's integration and intelligence. This solution not only shortens the vacuuming time, simplifies the hardware structure, enhances real-time control capabilities, optimizes the coupling of various structures, and reduces equipment size and maintenance complexity, but also significantly enhances the system's scalability and reliability. By dividing the existing sample chamber into independently controlled pre-evacuation chambers and working chambers, localized vacuuming is achieved, thereby significantly reducing the time and space occupied for vacuuming, shortening the single vacuuming time from the traditional tens of minutes to seconds, especially in scenarios with frequent sample changes, greatly improving experimental efficiency. This system integrates a precision vacuum mechanical pump, vacuum gauge, user-friendly control software, a highly efficient miniaturized Raspberry Pi controller, a real-time data processing host computer, and partitioned vacuuming pipelines, allowing each area to be vacuumed independently without waiting for the entire sample chamber to complete vacuum breaking and evacuation, thus improving experimental efficiency and reducing equipment size, weight, and maintenance complexity. By combining Raspberry Pi and STM32 controllers to build a compact control architecture, replacing the traditional bulky independent controller, and combining modularly laid-out multi-channel relays, switching power supplies and other components, the size of the vacuum control system is effectively reduced, saving experimental space.

[0090] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems and devices described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. The device embodiments described above are merely illustrative. For example, the division of units is only a logical functional division; 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. Another point is that the displayed or discussed mutual coupling or direct coupling or communication connection may be through some communication interfaces; the indirect coupling or communication connection of devices or units may be electrical, mechanical, or other forms.

[0091] 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.

[0092] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0093] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a processor-executable, non-volatile, computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0094] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A vacuum control system for a lithography machine, characterized in that, The vacuum control system includes a pre-evacuation chamber, a working chamber, a lithography machine chamber, a gate valve, a first vacuum gauge, a connecting valve, a second vacuum gauge, a mechanical pump, a first mechanical pump valve, a molecular pump, a first control device, and a second control device. The working chamber is located between the pre-evacuation chamber and the lithography machine chamber. A gate valve is located between the sample delivery tracks corresponding to the working chamber and the pre-evacuation chamber. A mechanical pump is connected to the pre-evacuation chamber via a first mechanical pump valve. A first vacuum gauge is connected to the pre-evacuation chamber. A connecting valve is located between the pre-evacuation chamber and the working chamber. A molecular pump is connected to the working chamber. A second vacuum gauge is connected to the lithography machine chamber. The lithography machine chamber is in communication with the working chamber. A second control device is connected to the first control device, the gate valve, the first vacuum gauge, the connecting valve, the second vacuum gauge, the mechanical pump, the molecular pump, and the first mechanical pump valve. The first control device is configured to: acquire the working chamber vacuum level of the working chamber collected by the second vacuum gauge in real time through the second control device; when the working chamber vacuum level does not reach the preset working chamber vacuum level, send an open signal for the molecular pump to the second control device to perform a working chamber evacuation operation; and when the working chamber vacuum level reaches the preset working chamber vacuum level, send a close signal for the molecular pump to the second control device. In response to the start command of the vacuuming operation, an open signal for the first mechanical pump valve is sent to the second control device to perform a pre-vacuuming operation on the pre-vacuuming chamber in which the preset sample has been placed. The second control device acquires the pre-evacuation chamber vacuum degree collected by the first vacuum gauge. When the pre-evacuation chamber vacuum degree reaches the preset pre-evacuation chamber vacuum degree, a closing signal for the first mechanical pump valve is sent to the second control device to stop the pre-evacuation chamber vacuuming operation. An opening signal for the connecting valve is sent to the second control device, and a closing signal for the connecting valve is sent to the second control device after a preset connecting time interval. Send an open signal to the second control device for the valve to connect the sample delivery track of the pre-extraction chamber with the sample delivery track of the working chamber. After the preset sample moves to the working chamber, send a close signal to the second control device for the valve.

2. The vacuum control system according to claim 1, characterized in that, The vacuum control system further includes a third control device connected to the lithography machine cavity, in which the lithography machine is housed. The first control device is configured to send an exposure request signal to the third control device after the preset sample moves to the working chamber and the gate valve closes, so that the third control device controls the lithography machine to perform exposure processing on the preset sample. Upon receiving the exposure end command transmitted by the third control device, an open signal for the connecting valve is sent to the second control device, and a closed signal for the connecting valve is sent to the second control device after a preset connecting time interval. Send an open signal to the second control device for the valve to move the exposed preset sample from the working chamber to the pre-extraction chamber, and send a close signal to the second control device for the valve to disconnect the connection between the working chamber and the pre-extraction chamber.

3. The vacuum control system according to claim 2, characterized in that, The vacuum control system further includes at least one image acquisition device and a display screen. Each image acquisition device is connected to the first control device and the display screen. At least one image acquisition device is disposed in the working chamber for capturing images of the chamber, and the display screen is used to display the images of the chamber. The first control device is configured to control the device status of each image acquisition device.

4. The vacuum control system according to claim 2, characterized in that, The device status of the image acquisition device includes power-on status and power-off status. The first control device is configured to send a power-off control signal to the image acquisition device, switching to the power-off state, before sending an exposure request signal to the third control device. After receiving the exposure end command transmitted by the third control device, a power-on control signal is sent to the image acquisition device to switch to the power-on state.

5. The vacuum control system according to claim 2, characterized in that, The vacuum control system also includes a vent valve, which is disposed between the pre-evacuation chamber and the second control device. The first control device is configured to: after disconnecting the connection between the working chamber and the pre-evacuation chamber, send an opening signal to the second control device for the vent valve to perform a vacuum release operation on the pre-evacuation chamber; and when the opening duration of the vent valve reaches a preset vacuum release duration, send a closing signal to the second control device for the vent valve to facilitate the removal of the exposed preset sample placed in the pre-evacuation chamber.

6. The vacuum control system according to claim 1, characterized in that, The vacuum control system further includes a second mechanical pump valve, a gas storage tank, and a third vacuum gauge. One end of the molecular pump is connected to the working chamber and / or the lithography machine chamber, and the other end of the molecular pump is connected to one end of the gas storage tank. The other end of the gas storage tank is connected to the second mechanical pump valve, which is connected to the mechanical pump. The third vacuum gauge is connected to both the gas storage tank and the second control device. The first control device is configured to: acquire the vacuum degree of the gas storage tank collected by the third vacuum gauge through the second control device; when the vacuum degree of the gas storage tank does not reach the preset vacuum degree, send an open signal for the second mechanical pump valve to the second control device; and when the vacuum degree of the gas storage tank reaches the preset vacuum degree, send a closed signal for the second mechanical pump valve to the second control device.

7. The vacuum control system according to claim 2, characterized in that, The first control device is configured as follows: After the preset sample is moved to the working chamber and the valve is closed, the pre-vacuum degree of the pre-vacuum chamber collected by the first vacuum gauge is obtained by the second control device. When the pre-vacuum chamber vacuum degree reaches the vacuum degree of the mechanical pump, a start signal for the mechanical pump is sent to the second control device, and an open signal for the first mechanical pump valve is sent to execute the pre-vacuum chamber vacuuming operation. When the pre-vacuum chamber vacuum degree reaches the preset pre-vacuum chamber vacuum degree, a close signal for the first mechanical pump valve is sent to the second control device to stop the execution of the pre-vacuum chamber vacuuming operation.

8. The vacuum control system according to any one of claims 1 to 7, characterized in that, The second control device includes a controller, a first step-down circuit, a second step-down circuit, a network communication circuit, a host computer communication circuit, a reset circuit, and a multi-channel relay. The input power supply is connected to one end of the first step-down circuit. The other end of the first step-down circuit is connected to one end of the network communication circuit and one end of the second step-down circuit. The other end of the second step-down circuit is connected to the power supply of the controller. The other end of the network communication circuit is connected to the controller. The network port of the network communication circuit is used to connect a vacuum gauge. The host computer communication circuit is located between the controller and the first control device. The reset circuit is connected to the reset pin of the controller. The multi-channel relay is located between the controller and multiple preset control valves. The multiple preset control valves include the gate valve, the first mechanical pump valve, the second mechanical pump valve, the connecting valve, and the vent valve. One of the multi-channel relays corresponds to one preset control valve.

9. The vacuum control system according to claim 8, characterized in that, The controller is configured to determine the vacuum level detected by the vacuum gauge using the following formula: in, This refers to the vacuum level detected by the vacuum gauge. This refers to the output voltage value of the vacuum gauge calculated by the controller based on the voltage value detected at the other end of the network communication circuit.

10. The vacuum control system according to any one of claims 1 to 7, characterized in that, The first control device includes a Raspberry Pi processor.

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