Alignment control method of photomask for photolithography machine

Abstract

A method for controlling mask alignment of a lithography machine is provided, comprising: receiving an alignment message into a message queue when a state machine is in an initial idle state; receiving a movement message of an electrical device used to control mask alignment of the lithography machine into the message queue when the state machine is in a system alignment state; ejecting the movement message of the electrical device used to control mask alignment of the lithography machine from the message queue to drive the state machine to control the movement of the electrical device; and receiving a movement notification message of the electrical device into position into the message queue, and ejecting the movement notification message of the electrical device from the message queue to drive the state machine to perform mask alignment operations of the lithography machine. In this way, the alignment process can be interrupted and resumed in real time, and electrical devices can be controlled asynchronously and concurrently.

Description

Technical Field

[0001] The present application relates to the technical field of photolithography machines, and more specifically, to a mask alignment control method for a photolithography machine. Background Art

[0002] The mask alignment control of the lithography machine refers to ensuring the alignment accuracy between the mask and the silicon wafer during the lithography process, so that the pattern on the mask is completely aligned with the pattern on the silicon wafer, ensuring the accurate transfer of the pattern during the lithography process.

[0003] Mask alignment control is a complex process involving preparations before alignment, including transferring the mask to the receiving position by the robot, moving the mask workbench to the receiving position, placing the mask, moving the mask workbench to the alignment position, rough alignment of the mask, moving the silicon wafer workbench FM (Fiducial Mark) to the mask alignment position, focusing, and fine alignment of the mask.

[0004] In order to carry out efficient alignment considering performance, it is necessary to control the concurrent operation of electrical equipment according to process rationality to maximize production.

[0005] Therefore, it is desirable to provide an improved reticle alignment control solution for a lithography machine. Summary of the Invention

[0006] An embodiment of the present application provides a mask alignment control method for a lithography machine, which implements mask alignment through a state machine driven by a message queue, can interrupt and restore the alignment process in real time, and asynchronously and concurrently control electrical equipment.

[0007] According to one aspect of the present application, a method for controlling the alignment of a photomask of a lithography machine is provided, comprising: when a state machine is in an initial idle state, receiving an alignment message into a message queue; when the state machine is in a system alignment state, receiving a movement message of an electrical device for controlling the alignment of the photomask of the lithography machine into the message queue; popping the movement message of the electrical device for controlling the alignment of the photomask of the lithography machine out of the message queue to drive the state machine to control the movement of the electrical device; and receiving a movement-in-place notification message of the electrical device into the message queue, and popping the movement-in-place notification message of the electrical device from the message queue to drive the state machine to perform the mask alignment operation of the lithography machine.

[0008] In the above-mentioned mask alignment control method of the lithography machine, receiving the movement message of the electrical equipment used to control the mask alignment of the lithography machine into the message queue includes: parallel / serial receiving the message used to control the mask transmission control robot to move to the receiving position and control the mask workbench to move to the receiving position into the message queue.

[0009] In the above-mentioned mask alignment control method of the lithography machine, the movement message of the electrical equipment used to control the mask placement of the lithography machine is popped out of the message queue to drive the state machine, and the control of the movement of the electrical equipment includes: popping out the message of controlling the mask transmission and control robot to move to the receiving position from the message queue to drive the state machine to enter the mask transmission and control robot movement control state, for executing the operation of moving the mask transmission and control robot to the receiving position; and popping out the message of controlling the mask workbench to move to the receiving position from the message queue to drive the state machine to enter the mask workbench movement control state, for executing the operation of moving the mask workbench to the receiving position.

[0010] In the above-mentioned mask alignment control method of the lithography machine, the operation of moving the mask transmission control robot to the receiving position and the message of controlling the mask workbench to move to the receiving position are popped out of the message queue and executed synchronously and concurrently.

[0011] In the above-mentioned mask alignment control method of the lithography machine, receiving the move-in-place notification message of the electrical equipment into the message queue, and popping out the move-in-place notification message of the electrical equipment from the message queue to drive the state machine to perform the mask alignment operation of the lithography machine includes: when receiving the move-in-place notification message of the mask control robot into the message queue, and popping out the move-in-place notification message of the mask control robot from the message queue, the state machine enters the mask control robot movement completion state from the mask workbench movement control state, and the in-place mark of the mask control robot indicates that the mask control robot is in place.

[0012] In the above-mentioned mask alignment control method of the lithography machine, receiving the movement-in-place notification message of the electrical device into the message queue, and popping out the movement-in-place notification message of the electrical device from the message queue to drive the state machine for performing the mask alignment operation of the lithography machine includes: determining whether the mask workbench has moved to the receiving position based on the in-place mark of the mask workbench; in response to the mask workbench moving to the receiving position, pushing the message for placing the mask into the message queue; and, in response to the mask workbench not moving to the receiving position, keeping the message queue empty.

[0013] In the above-mentioned mask alignment control method of the lithography machine, in response to the fact that the mask workbench has not moved to the receiving position, keeping the message queue empty further includes: in response to receiving the movement notification message of the mask workbench into position, entering the message queue, and popping out the movement notification message of the mask workbench from the message queue, driving the state machine from the mask control robot movement completion state to the mask workbench movement completion state.

[0014] In the above-mentioned mask alignment control method of the lithography machine, receiving the movement-in-place notification message of the electrical device into the message queue, and popping out the movement-in-place notification message of the electrical device from the message queue to drive the state machine to perform the mask alignment operation of the lithography machine includes: when the in-place mark of the mask transmission and control robot indicates that the mask transmission and control robot is in place, and the in-place mark of the mask workbench indicates that the mask workbench is in place, receiving the plate placement message into the message queue; popping out the plate placement message from the message queue to drive the state machine to enter the plate placement state for performing the plate placement operation; when the plate placement operation is completed, receiving the mask placement notification message into the message queue; and after popping out the mask placement notification message from the message queue, determining that the mask placement operation is completed.

[0015] In the above-mentioned mask alignment control method of the lithography machine, it further includes: receiving an external pause alignment command or resume alignment command, pushing it into the message queue with the highest priority; and when the pause alignment command or resume alignment command is popped out from the message queue, executing the interruption or resumption operation of the mask alignment process.

[0016] In the above-mentioned mask alignment control method of the lithography machine, executing the interrupt operation of the mask alignment process includes: driving the state machine to retain the current operating state.

[0017] An embodiment of the present application provides a mask alignment control method for a lithography machine, which implements mask alignment through a state machine driven by a message queue, can interrupt and restore the alignment process in real time, and asynchronously and concurrently control electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Various other advantages and benefits of the present application will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The drawings in the specification are intended only to illustrate preferred embodiments and are not to be construed as limiting the present application. Obviously, the drawings described below are merely examples of the present application, and those skilled in the art can derive other drawings based on these drawings without inventive effort. Throughout the drawings, the same reference numerals denote the same components.

[0019] Figure 1 The figure illustrates a schematic flow chart of a mask alignment control method of a lithography machine according to an embodiment of the present application.

[0020] Figure 2 A schematic diagram of a mask alignment control method for a lithography machine according to an embodiment of the present application is shown for a mask placement operation. DETAILED DESCRIPTION

[0021] Below, the exemplary embodiments according to the present application will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application, and it should be understood that the present application is not limited to the exemplary embodiments described herein.

[0022] Figure 1 The figure illustrates a schematic flow chart of a mask alignment control method of a lithography machine according to an embodiment of the present application.

[0023] like Figure 1 As shown, the mask alignment control method of the lithography machine according to the embodiment of the present application includes the following steps.

[0024] In step S110, when the state machine is in an initial idle state, an alignment message is received and entered into a message queue. Specifically, at the start of the reticle alignment control process for the lithography machine, the state machine is in an initial idle state, and the message queue is empty. At this point, to perform reticle alignment, an alignment message, such as an alignment start message or an alignment start message, is pushed into the message queue. As a result, the message queue now contains alignment messages.

[0025] Specifically, in the embodiment of the present application, the main elements of the state machine include: state, event, action, etc., that is, the state machine mainly implements the monitoring of state and event, and performs corresponding state transitions for different states and events to achieve process-free operation of complex processes.

[0026] In addition, in the embodiment of the present application, the message queue mainly stores the following types of messages:

[0027] 1) External commands, including pause, terminate and other interrupt processing;

[0028] 2) Internal state set;

[0029] 3) Asynchronous operation response messages, including error and success messages;

[0030] 4) Real-time events, such as abnormal events of electrical equipment.

[0031] Here, considering that in the photomask alignment control process of the lithography machine, the actual operation behavior of the entire control system is asynchronous operation, the process only needs to focus on synchronous control, not the actual operation behavior, and single-thread single-queue control simplifies implementation. Therefore, in the embodiment of the present application, the message queue is mainly monitored by a single thread, and the production and consumption of states are simultaneously realized within the single thread. Specifically, the production of a state refers to the entry of a new state into the queue, while the consumption of a state refers to the execution of the behavioral operation for the current state. Here, the behavioral operation is asynchronous, and the corresponding operation is processed by the multi-threaded device access layer of the electrical device.

[0032] Step S120, when the state machine is in the system alignment state, receives a movement message of the electrical equipment used to control the alignment of the photomask of the lithography machine and enters the message queue. That is, in an embodiment of the present application, when controlling the alignment of the photomask of the lithography machine, for example, in the plate placement operation, it is necessary to control the photomask transmission and control robot to the plate receiving position, and control the photomask workbench to move to the plate receiving position to achieve plate placement. Usually, this needs to be implemented with two messages, namely the photomask transmission and control robot movement message and the photomask workbench movement message. In the actual control process, these two messages can enter the message queue in parallel or in series, that is, in an embodiment of the present application, the message queue can support both parallel and serial when driving the state flow. Among them, parallel processing refers to pushing concurrent states into the queue at the same time, while serial processing refers to pushing only one state into the queue, waiting for the completed response message, and then pushing the next state into the queue.

[0033] Therefore, in the mask alignment control method of the lithography machine according to an embodiment of the present application, receiving the movement message of the electrical equipment used to control the mask alignment of the lithography machine into the message queue includes: parallel / serial receiving the message used to control the mask transmission control robot to move to the receiving position and control the mask workbench to move to the receiving position into the message queue.

[0034] Step S130, popping the movement message of the electrical equipment used to control the alignment of the photomask of the lithography machine out of the message queue to drive the state machine to control the movement of the electrical equipment. Here, as described above, taking the plate placement operation as an example, when the actual operation behavior of the control system is an asynchronous operation, for the messages for controlling the movement of the photomask transmission and control robot to the receiving position and the control of the photomask workbench to the receiving position that enter the message queue in parallel, one of them, such as the message for controlling the movement of the photomask transmission and control robot to the receiving position, can be first popped out of the message queue, that is, driving the state machine to enter the photomask transmission and control robot movement control state, thereby calling the device access layer code of the photomask transmission and control robot to control the execution of the operation of moving the photomask transmission and control robot to the receiving position.

[0035] Afterwards, the message for controlling the movement of the mask workbench to the receiving position is popped out of the message queue, that is, the state machine is driven to enter the mask workbench movement control state, thereby calling the device access layer code of the mask workbench to control the execution of the operation of moving the mask workbench to the receiving position.

[0036] Here, after the message for controlling the photomask plate transmission and control robot to move to the receiving position pops out of the message queue, while the driving state machine executes the operation of moving the photomask plate transmission and control robot to the receiving position, the message for controlling the photomask plate workbench to move to the receiving position can be popped out of the message queue. Therefore, in the embodiment of the present application, the operation of moving the photomask plate transmission and control robot to the receiving position and the message for controlling the photomask plate workbench to move to the receiving position are essentially executed synchronously and concurrently.

[0037] That is, in the mask alignment control method of the lithography machine according to the embodiment of the present application, the movement message of the electrical equipment used to control the mask placement of the lithography machine is popped out of the message queue to drive the state machine, and the control of the movement of the electrical equipment includes: popping out the message of controlling the mask transmission and control robot to move to the receiving position from the message queue to drive the state machine to enter the mask transmission and control robot movement control state, for executing the operation of moving the mask transmission and control robot to the receiving position; and popping out the message of controlling the mask workbench to move to the receiving position from the message queue to drive the state machine to enter the mask workbench movement control state, for executing the operation of moving the mask workbench to the receiving position.

[0038] Moreover, in the mask alignment control method of the lithography machine according to the embodiment of the present application, the operation of moving the mask transmission control robot to the receiving position and the message of controlling the mask workbench to move to the receiving position pop out of the message queue and are executed synchronously and concurrently.

[0039] Step S140: Receive the notification message of the electrical device moving into position and enter the message queue, and pop the notification message of the electrical device moving into position from the message queue to drive the state machine to perform the mask alignment operation of the lithography machine. For example, in the above-mentioned example of the plate placement operation, when the notification message of the mask transmission and control robot moving to the receiving position is received and enters the message queue, the state machine is still in the mask workbench movement control state. Thereafter, by popping the notification message of the mask transmission and control robot moving to the receiving position into position from the message queue, the state machine enters the mask transmission and control robot movement completion state. At this time, the in-position flag of the mask transmission and control robot can be set to indicate that the mask transmission and control robot is in position.

[0040] That is, in the mask alignment control method of the lithography machine according to the embodiment of the present application, receiving the move-in-place notification message of the electrical equipment into the message queue, and popping out the move-in-place notification message of the electrical equipment from the message queue to drive the state machine for performing the mask alignment operation of the lithography machine includes: when the move-in-place notification message of the mask control robot is received into the message queue, and the move-in-place notification message of the mask control robot is popped out of the message queue, the state machine enters the mask control robot movement completion state from the mask workbench movement control state, and the in-place mark of the mask control robot indicates that the mask control robot is in place.

[0041] At this time, it is possible to further determine whether the reticle workbench has moved to the receiving position. Similarly, the in-position mark of the reticle workbench can be set to determine whether the reticle workbench is in position. Here, if the reticle workbench has moved to the position, the message for placing the reticle can be pushed into the message queue. If there is no in-position mark for the reticle workbench, the message queue remains empty.

[0042] That is, in the mask alignment control method of the lithography machine according to the embodiment of the present application, the moving-in-place notification message of the electrical device is received into the message queue, and the moving-in-place notification message of the electrical device is popped out from the message queue to drive the state machine for performing the mask alignment operation of the lithography machine, including: determining whether the mask workbench is moved to the receiving position based on the in-place mark of the mask workbench; in response to the mask workbench moving to the receiving position, pushing the message for placing the mask into the message queue; and, in response to the mask workbench not moving to the receiving position, keeping the message queue empty.

[0043] If the reticle worktable has not moved to the receiving position, a message notifying the reticle worktable of its position is further received. After the message is received, the message queue is entered, and the message is ejected from the message queue, the state machine enters the reticle worktable position state from the reticle control robot position state. Furthermore, the position indicator of the reticle worktable can indicate that the reticle worktable is in position.

[0044] That is, in the mask alignment control method of the lithography machine according to the embodiment of the present application, in response to the mask workbench not moving to the receiving position, keeping the message queue empty further includes: in response to receiving the movement notification message of the mask workbench into position, entering the message queue, and popping out the movement notification message of the mask workbench from the message queue, driving the state machine from the mask control robot movement completion state to the mask workbench movement completion state.

[0045] Thus, when the in-position mark of the reticle transfer robot indicates that the reticle transfer robot is in position, and the in-position mark of the reticle worktable indicates that the reticle worktable is in position, a reticle alignment message enters the message queue. For example, when a reticle placement operation is performed, a reticle placement message enters the message queue. Thus, when the reticle placement message is popped out of the message queue, the state machine is driven to enter the reticle placement state, and the reticle placement operation is performed.

[0046] Afterwards, when the plate placing operation is completed, the received mask plate in place notification message enters the message queue, and after the mask plate in place notification message is popped up, it is determined that the mask plate placing operation is completed.

[0047] Therefore, in the mask alignment control method of the lithography machine according to the embodiment of the present application, receiving the movement-in-place notification message of the electrical device into the message queue, and popping out the movement-in-place notification message of the electrical device from the message queue to drive the state machine to perform the mask alignment operation of the lithography machine includes: when the in-place mark of the mask transmission and control robot indicates that the mask transmission and control robot is in place, and the in-place mark of the mask workbench indicates that the mask workbench is in place, receiving the plate placement message into the message queue; popping out the plate placement message from the message queue to drive the state machine to enter the plate placement state for performing the plate placement operation; when the plate placement operation is completed, receiving the mask placement notification message into the message queue; and after popping out the mask placement notification message from the message queue, determining that the mask placement operation is completed.

[0048] Here, those skilled in the art can understand that in the photomask alignment control method of the lithography machine according to the embodiment of the present application, the photomask alignment operation is not limited to the plate placing operation as described above, but can also be other operations that require controlling the movement of electrical equipment to achieve photomask alignment. For example, in the fine alignment process of the photomask, it is necessary to control the electrical equipment to move the photomask workbench and the silicon wafer workbench to achieve fine alignment of the photomask and the silicon wafer. At this time, it is only necessary to replace the movement control of the photomask transmission control manipulator and the photomask workbench in the plate placing operation as described above with the movement control of the photomask workbench and the silicon wafer workbench. The control process is exactly the same and will not be repeated here.

[0049] Figure 2 The figure shows a schematic diagram of the mask alignment control method of the lithography machine according to the embodiment of the present application for the mask placement operation. Here, Figure 2 The above has been explained in detail using the plate placement operation as an example, so I will not repeat it here.

[0050] Furthermore, in the embodiments of the present application, the process can be interrupted and resumed at any time during the execution of the mask alignment operation. Specifically, by entering the external pause alignment command and resume alignment command into the message queue with the highest priority, the process can be interrupted and resumed when the command is ejected from the message queue.

[0051] Specifically, the message queue can prioritize messages that require real-time processing. For example, external commands to pause or resume alignment can be given the highest priority and placed directly at the head of the message queue. When the message is ejected from the queue, the pause or resume operation is directly executed. Furthermore, when a process is paused, the state machine can be driven to retain the current state, allowing for seamless resumption of the alignment process.

[0052] Therefore, in the mask alignment control method of the lithography machine according to the embodiment of the present application, it further includes: receiving an external pause alignment command or resume alignment command, pushing it into the message queue with the highest priority; and when the pause alignment command or resume alignment command is popped out from the message queue, executing the interruption or resumption operation of the mask alignment process.

[0053] Furthermore, in the mask alignment control method of the lithography machine according to an embodiment of the present application, executing the interrupt operation of the mask alignment process includes: driving the state machine to retain the current operating state.

[0054] The basic principles of the present application have been described above in conjunction with specific embodiments. However, it should be noted that the advantages, strengths, and effects mentioned in this application are merely illustrative and not restrictive, and it should not be assumed that these advantages, strengths, and effects are required of each embodiment of this application. In addition, the specific details disclosed above are merely illustrative and facilitating understanding, and are not restrictive. The above details do not limit this application to necessarily being implemented using the above specific details.

[0055] The block diagrams of the devices, devices, equipment, and systems involved in this application are merely illustrative examples and are not intended to require or imply that they must be connected, arranged, or configured in the manner shown in the block diagrams. As will be appreciated by those skilled in the art, these devices, devices, equipment, and systems can be connected, arranged, or configured in any manner. Words such as "include," "comprise," "have," and the like are open-ended words, meaning "including but not limited to," and can be used interchangeably therewith. The words "or" and "and" used herein refer to the words "and / or" and can be used interchangeably therewith, unless the context clearly indicates otherwise. The word "such as" used herein refers to the phrase "such as but not limited to," and can be used interchangeably therewith.

[0056] It should also be noted that in the apparatus, device, and method of the present application, each component or each step can be decomposed and / or recombined, and such decomposition and / or recombination should be regarded as equivalent solutions of the present application.

[0057] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use the present application. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0058] The above description has been provided for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain variations, modifications, alterations, additions, and sub-combinations thereof.

Claims

1. A method for controlling mask alignment of a lithography machine, comprising: When the state machine is in the initial idle state, the received alignment message enters the message queue; When the state machine is in a system alignment state, receiving a mobile message of an electrical device for controlling the alignment of a photomask of the lithography machine into the message queue; Popping a movement message of an electrical device for controlling the alignment of a photomask of the lithography machine out of the message queue to drive the state machine for controlling the movement of the electrical device; as well as receiving a notification message of the electrical device being moved into position and entering the message queue, and popping the notification message of the electrical device being moved into position from the message queue to drive the state machine to perform a mask alignment operation of the lithography machine; The step of receiving a movement message of an electrical device for controlling the alignment of a mask plate of the lithography machine into the message queue includes: receiving a message for controlling a mask plate transmission and control robot to move to a receiving position and controlling a mask plate workbench to move to a receiving position in parallel or serially into the message queue; Popping a movement message of an electrical device for controlling the mask placement of the lithography machine out of the message queue to drive the state machine, and controlling the movement of the electrical device includes: popping a message for controlling the mask transmission and control robot to move to a receiving position out of the message queue to drive the state machine to enter a mask transmission and control robot movement control state, for executing an operation of moving the mask transmission and control robot to the receiving position; and popping a message for controlling the mask workbench to move to the receiving position out of the message queue to drive the state machine to enter a mask workbench movement control state, for executing an operation of moving the mask workbench to the receiving position; The message queue implements the enqueueing of new messages and the execution of behavioral operations on current messages within a single thread.

2. The method for controlling the alignment of a photomask of a lithography machine according to claim 1, wherein: The operation of moving the photomask plate transmission control robot to the receiving position and the message of controlling the photomask plate workbench to move to the receiving position are popped out of the message queue and executed synchronously and concurrently.

3. The method for controlling the alignment of a photomask of a lithography machine according to claim 2, wherein: Receiving a notification message of the electrical device being moved into position into the message queue, and popping the notification message of the electrical device being moved into position from the message queue to drive the state machine to perform a mask alignment operation of the lithography machine includes: When the notification message of the movement of the mask plate control robot into position is received and enters the message queue, and the notification message of the movement of the mask plate control robot is popped out of the message queue, the state machine enters the mask plate control robot movement completion state from the mask plate workbench movement control state, and the arrival mark of the mask plate control robot indicates that the mask plate control robot is in position.

4. The method for controlling mask alignment of a lithography machine according to claim 3, wherein: Receiving a notification message of the electrical device being moved into position into the message queue, and popping the notification message of the electrical device being moved into position from the message queue to drive the state machine to perform a mask alignment operation of the lithography machine includes: Determining whether the photomask workbench has moved to a receiving position based on an in-position mark of the photomask workbench; In response to the photomask workbench moving to the receiving position, pushing a message for placing the photomask into the message queue; and In response to the photomask workbench not moving to the receiving position, the message queue is kept empty.

5. The method for controlling mask alignment of a lithography machine according to claim 4, wherein: In response to the photomask workbench not moving to the receiving position, keeping the message queue empty further includes: In response to receiving the notification message of the mask workbench moving into position, the message queue is entered, and the notification message of the mask workbench moving into position is popped out from the message queue, driving the state machine from the mask control robot movement completion state to the mask workbench movement completion state.

6. The method for controlling mask alignment of a lithography machine according to claim 5, wherein: Receiving a notification message of the electrical device being moved into position into the message queue, and popping the notification message of the electrical device being moved into position from the message queue to drive the state machine to perform a mask alignment operation of the lithography machine includes: When the arrival mark of the mask plate transmission and control robot indicates that the mask plate transmission and control robot is in place, and the arrival mark of the mask plate workbench indicates that the mask plate workbench is in place, receiving a plate release message and entering it into the message queue; Popping the version release message out of the message queue to drive the state machine to enter the version release state for executing the version release operation; When the plate placement operation is completed, receiving a mask plate arrival notification message and entering it into the message queue; and After the reticle arrival notification message is popped out from the message queue, it is determined that the reticle placement operation is completed.

7. The method for controlling mask alignment of a lithography machine according to claim 1 , further comprising: Receiving an external pause alignment command or resume alignment command, and pushing it into the message queue with the highest priority; as well as, When the pause alignment command or the resume alignment command is popped out from the message queue, the interruption or resumption operation of the mask alignment process is executed.

8. The method for controlling mask alignment of a lithography machine according to claim 7, wherein: The interruption operation of executing the mask alignment process includes: The state machine is driven to retain the current running state.

Images