Automatic safety protection system and method for wafer defect detection equipment

Abstract

The invention relates to the technical field of wafer defect detection, in particular to an automatic safety protection system and method for wafer defect detection equipment, and the system mainly comprises a hardware automatic protection system and a software monitoring and recording system. The hardware automatic protection system comprises a safety door state monitoring module, a safety door bypass module, an emergency response module, a vacuum state monitoring module, a compressed air state monitoring module, an automatic protection processing module, a motion control module and a light source control module. The system completely depends on hardware to realize an automatic safety protection function. No upper computer software or embedded software is involved in the automatic protection process, and real-time, rapid and reliable safety protection response is guaranteed. After the automatic protection is triggered, before an operator confirms that the safety risk is relieved and manual intervention operation is carried out, the automatic protection system keeps the triggering state unchanged. Meanwhile, the special application requirements of professional training equipment maintenance personnel in the equipment debugging and maintenance process are met through control of the bypass switch.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer defect detection, and in particular to an automatic safety protection system and method for wafer defect detection equipment. Background Art

[0002] In the semiconductor device manufacturing process, it is necessary to detect wafer defects early in the process, find the cause of the defects in time and improve the process, and mark the defects to prevent the defective grains from continuing to be processed and manufactured, which will affect the yield and productivity. Therefore, wafer defect detection is a key means to improve the yield and productivity of semiconductor devices.

[0003] Wafer defect detection equipment is usually based on automated processes, mainly including wafer loading and unloading and wafer inspection. The wafer loading and unloading process involves vacuum adsorption and high-speed movement, and the wafer inspection process involves vacuum adsorption, high-speed movement, high-power lasers, and ultraviolet or short-wavelength lasers. At present, the detection equipment is mainly controlled by the host computer or PLC (programmable logic controller). The host computer needs to handle multiple tasks such as detection process control, detection data collection, status monitoring, and detection data calculation and processing. It may face priority conflicts and other problems, resulting in the inability to guarantee the timeliness of status monitoring and process control related to safety protection. When processing complex logic, the real-time performance and stability of PLC will decrease. Therefore, the detection equipment needs an automatic protection system that relies entirely on hardware to ensure the safety of equipment operation, provide safety protection for equipment operators, and meet the needs of professionally trained equipment maintenance personnel during equipment commissioning and maintenance. Summary of the invention

[0004] In order to solve the problem of delayed protection caused by the need for software intervention when wafer defect detection equipment uses a host computer or PLC for safety control, the present invention proposes an automatic safety protection system and method for wafer defect detection equipment. By integrating multiple safety protection mechanisms and adopting a completely hardware approach, potential safety risks can be prevented reliably and effectively, while ensuring the safety of operators and meeting the special application scenarios of professionally trained maintenance personnel.

[0005] The present invention is implemented by adopting the following technical scheme: an automatic safety protection system for wafer defect detection equipment, including a hardware automatic protection system, the hardware automatic protection system includes a safety door state monitoring module, a safety door bypass module, an emergency response module, a vacuum state monitoring module, a compressed air state monitoring module, an automatic protection processing module, a motion control module and a light source control module; the safety door state monitoring module is responsible for the cascade and switch state output of the equipment microenvironment door, and the equipment microenvironment door is equipped with a safety switch. The safety switches of all door bodies are connected in series through a cascade method to achieve that when any door body is opened, the final output signal state will change; the safety door bypass module is responsible for the bypass function of the equipment safety door. When the maintenance personnel need to debug or maintain the equipment during the operation of the equipment, the bypass control switch is closed. At this time, opening the equipment microenvironment door will not trigger the automatic protection, thereby ensuring the normal progress of the debugging and maintenance work; the emergency response module is responsible for when an emergency occurs during the use or maintenance of the equipment, the operator triggers the automatic safety protection function by quickly pressing the emergency switch , multiple emergency stop switches are connected in series to achieve that pressing any switch can trigger an emergency stop signal; the vacuum state monitoring module is responsible for monitoring the status of all vacuum ports in the equipment and outputting logic operations. By setting the threshold of the vacuum meter, each vacuum meter outputs a vacuum meter signal, which is logically high when normal and logically low when abnormal. All vacuum meter signals perform logic AND operations, and output vacuum state signals to the automatic protection processing module; the compressed air state monitoring module is responsible for monitoring the status of all compressed air ports in the equipment and outputting logic operations. By setting the threshold of the pressure gauge, each pressure gauge outputs a pressure gauge signal, which is logically high when normal and logically low when abnormal. All pressure gauge signals perform logic AND operations, and output compressed air state signals to the automatic protection processing module; the automatic protection processing module is responsible for the logic operation of the safety trigger signal in the equipment and the output of the corresponding control signal; the motion control module is responsible for responding to the instructions of the motion control part in the automatic protection processing module; the light source control module is responsible for responding to the instructions of the light source control part in the automatic protection processing module.

[0006] The above-mentioned automatic safety protection system for wafer defect detection equipment also includes a software monitoring and recording system. In order to monitor and record the equipment status in real time, the system collects all status signals through the digital signal interface module, transmits them to the host computer through the communication interface, records the status and writes them into the system operation log; the status signals include: all compressed air status signals, all vacuum status signals, all door switch signals, all emergency switch signals, bypass switch signals, and output motion emergency stop signals and light source shutdown signals; at the same time, the host computer software side displays these status signals in real time, and performs logical operations on the software side to cross-verify the hardware automatic protection system to ensure accuracy.

[0007] The above-mentioned protection method for the automatic safety protection system of wafer defect detection equipment sets a threshold value for the pressure gauge in the compressed air status monitoring module, so that the output signal is high under normal circumstances and the output is low under abnormal circumstances; similarly, a threshold value is also set for the vacuum gauge in the vacuum status monitoring module, so that the output signal is high under normal circumstances and the output is low under abnormal circumstances; the compressed air status signal and the vacuum status signal are logically ANDed in the automatic protection processing module and output as the pressure gauge status signal, so that when any pressure gauge or vacuum gauge is abnormal, the output pressure gauge status signal is low; the safety door status monitoring module connects the safety switches of all equipment microenvironment doors in series, and then connects them in parallel with the bypass switch in the safety door bypass module to output the safety door status signal; when the bypass switch is in the disconnected state, any door body is opened, which will trigger the safety switch of the corresponding door body to disconnect, so that the output safety door status signal becomes low, and when the bypass switch is in the closed state, any door body is opened, and the output safety door status signal is still high, so that it satisfies The requirements during debugging and maintenance are met; all emergency switches in the emergency response module are connected in series to output emergency switch status signals. When any emergency switch is triggered, the output emergency switch status signal will become low; the safety door status signal and the emergency switch status signal are logically ANDed in the automatic protection processing module to output the switch status signal; in this way, when any door is opened when the bypass switch is not closed or when the emergency switch is triggered, the switch status signal will become low; the pressure gauge status signal and the switch status signal are logically ANDed and then logically NOTed in the automatic protection processing module, so that when the pressure gauge status signal is low or the switch status signal is low, the motion emergency stop signal becomes high, and at this time all moving parts stop moving according to the set logic; the switch status signal is logically NOTed in the automatic protection processing module, and when the switch status signal is low, the light source shutdown signal becomes high, and all light sources with potential risks are turned off; at this time, the system enters the protection state, and the system will not automatically resume operation until the operator confirms that the safety risk has been eliminated and performs manual intervention.

[0008] The present invention discloses an automatic safety protection system for wafer defect detection equipment, which mainly includes a hardware automatic protection system and a software monitoring and recording system, wherein the hardware automatic protection system includes a safety door state monitoring module, a safety door bypass module, an emergency response module, a vacuum state monitoring module, a compressed air state monitoring module, an automatic protection processing module, a motion control module, and a light source control module. The system completely relies on hardware to realize the automatic safety protection function. There is no intervention of host computer software or embedded software in the automatic protection process, ensuring real-time, fast and reliable safety protection response. After the automatic protection is triggered, the automatic protection system maintains the trigger state unchanged before the operator confirms that the safety risk has been eliminated and performs manual intervention operations. At the same time, the control of the bypass switch meets the special application needs of professionally trained equipment maintenance personnel during equipment debugging and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of the system structure of the present invention.

[0010] Figure 2 It is a schematic diagram of signal connection of the hardware automatic protection system of the present invention.

[0011] Figure 3 It is a schematic diagram of signal connection of the software monitoring system of the present invention. DETAILED DESCRIPTION

[0012] An automatic safety protection system for wafer defect detection equipment mainly includes a hardware automatic protection system and a software monitoring and recording system.

[0013] The hardware automatic protection system includes a safety door status monitoring module, a safety door bypass module, an emergency response module, a vacuum status monitoring module, a compressed air status monitoring module, an automatic protection processing module, a motion control module, and a light source control module.

[0014] The safety door status monitoring module is responsible for the cascade and switch status output of the equipment micro-environment doors. The equipment micro-environment doors are all equipped with high-reliability safety switches. Through the cascade method, the safety switches of all doors are connected in series, so that when any door is opened, the final output signal state will change.

[0015] The safety door bypass module is responsible for the bypass function of the equipment safety door. When professionally trained maintenance personnel need to debug or maintain the equipment during operation, they close the bypass control switch. At this time, opening the equipment microenvironment door will not trigger automatic protection, ensuring the normal progress of debugging and maintenance work.

[0016] The emergency response module is responsible for triggering the automatic safety protection function by the operator quickly pressing the emergency switch when an emergency occurs during the use or maintenance of the equipment. The emergency switch is selected to be a normally closed switch with high reliability and ultra-long mechanical life, and with self-locking and resettable function. Some wafer defect detection equipment is large in size, and multiple emergency switches need to be arranged in the equipment to ensure that the operator can quickly press the emergency switch nearby in abnormal situations. At this time, multiple emergency switches are connected in series to achieve that pressing any switch can trigger an emergency stop signal.

[0017] The vacuum status monitoring module is responsible for monitoring the status of all vacuum ports in the equipment and outputting logic operations. By setting the threshold of the vacuum meter, each vacuum meter outputs a vacuum status signal, which is logically high when normal (the vacuum pressure value exceeds the threshold and outputs a high level), and logically low when abnormal (the vacuum pressure value does not exceed the threshold and outputs a low level).

[0018] The compressed air status monitoring module is responsible for monitoring the status of all compressed air ports in the equipment and the output of logical operations. By setting the threshold of the pressure gauge, each pressure gauge outputs a compressed air status signal, which is logically high when normal (the pressure value exceeds the threshold and outputs a high level), and logically low when abnormal (the pressure value does not exceed the threshold and outputs a low level).

[0019] The automatic protection processing module is responsible for the logical operation of the safety trigger signal in the equipment and the output of the corresponding control signal. The logical operation part of the module adopts a complete hardware method to achieve fast response and high reliability of automatic protection signal output.

[0020] The motion control module is responsible for responding to the instructions of the motion control part in the automatic protection processing module. For the motion part without wafers, it is required to stop the motion at the maximum deceleration. For the motion part with high-speed movement and wafers, it is required to stop the motion smoothly to avoid wafer damage.

[0021] The light source control module is responsible for responding to the control of the light source in the automatic protection processing module. For high-power laser and ultraviolet or short-wavelength laser light sources, when the automatic protection is triggered, these potentially harmful light sources are quickly turned off.

[0022] Figure 2 The system signal connection diagram is given, as shown in the figure: The pressure gauge is set with an appropriate threshold value so that the output signal is high under normal circumstances and low under abnormal circumstances. Similarly, the vacuum gauge is also set with an appropriate threshold value so that the output signal is high under normal circumstances and low under abnormal circumstances.

[0023] All barometer output signals are logically ANDed as compressed air status signals, so that when any air pressure is abnormal, the compressed air status signal output is low. All vacuum gauge output signals are logically ANDed as vacuum status signals, so that when any vacuum gauge is abnormal, the vacuum status signal output is low. The compressed air status signal and the vacuum status signal are logically ANDed in the automatic protection processing module and output as pressure gauge status signals, so that when any barometer or vacuum gauge is abnormal, the output pressure gauge status signal is low.

[0024] The safety switches of all equipment micro-environment doors are connected in series, and then connected in parallel with the bypass switch to output the safety door status signal. When the bypass switch is disconnected, any door body opened will trigger the safety switch of the corresponding door body to disconnect, so that the output safety door status signal becomes low. When the bypass switch is closed, any door body is opened, and the output safety door status signal is still high. In this way, special needs during debugging and maintenance are met. All emergency switches are connected in series to output emergency switch status signals. When any emergency switch is triggered, the output emergency switch status signal will become low. The safety door status signal and the emergency switch status signal are logically ANDed in the automatic protection processing module to output the switch status signal. In this way, when any door body is opened without closing the bypass switch, or when the emergency switch is triggered, the switch status signal will become low.

[0025] The pressure gauge status signal and the switch status signal are logically ANDed and then logically NOTed. In this way, when the pressure gauge status signal is low or the switch status signal is low, the motion emergency stop signal becomes high. At this time, all moving parts stop moving quickly or at a certain deceleration according to the set logic. When the switch status signal is low, the light source shutdown signal becomes high, and all light sources with potential risks are quickly shut down. At this time, the system enters the protection state. The system will not automatically resume operation until the operator confirms that the safety risk has been eliminated and performs manual intervention.

[0026] Software monitoring and recording system: In order to monitor and record the equipment status in real time, the system collects all status signals through the digital signal interface module, transmits them to the host computer through the communication interface, records the status and writes them into the system operation log. The status signals include: all barometer signals, all vacuum gauge signals, all door switch signals, all emergency switch signals, bypass switch signals, and output motion emergency stop signals and light source shutdown signals. At the same time, the host computer software side displays these status signals in real time, and performs logical operations on the software side, cross-verifying the hardware automatic protection system to ensure accuracy.

[0027] The beneficial effects of the present invention are: 1) The present invention proposes an automatic safety protection system that is completely implemented by hardware. There is no intervention of host computer software or embedded software in the automatic protection process, ensuring real-time and rapid protection response.

[0028] 2) The present invention proposes an automatic protection system for wafer defect detection equipment. The system monitors all safety-related signals in the detection equipment and controls the shutdown and stop of different risk sources according to the set trigger logic through hardware logic operations.

[0029] 3) The present invention proposes a safety door bypass method to meet special operating requirements during the debugging and maintenance of wafer defect detection equipment.

Claims

1. An automatic safety protection system for wafer defect detection equipment, characterized in that: It includes a hardware automatic protection system, which includes a safety door status monitoring module, a safety door bypass module, an emergency response module, a vacuum status monitoring module, a compressed air status monitoring module, an automatic protection processing module, a motion control module and a light source control module; the safety door status monitoring module is responsible for the cascade and switch status output of the equipment microenvironment door. The equipment microenvironment door is equipped with a safety switch. The safety switches of all door bodies are connected in series through the cascade method, so that when any door body is opened, the final output signal state will change; the safety door bypass module is responsible for the bypass function of the equipment safety door. When the maintenance personnel need to debug or maintain the equipment during the operation of the equipment, the bypass control switch is closed. At this time, opening the equipment microenvironment door will not trigger the automatic protection, ensuring the normal progress of the debugging and maintenance work; The emergency response module is responsible for the automatic safety protection function triggered by the operator by quickly pressing the emergency switch when an emergency occurs during the use or maintenance of the equipment. Multiple emergency stop switches are connected in series to achieve the emergency stop signal by pressing any switch; the vacuum state monitoring module is responsible for the monitoring and logical operation output of all vacuum port states in the equipment. By setting the threshold of the vacuum meter, each vacuum meter outputs a vacuum meter signal, which is logically high when normal and logically low when abnormal. All vacuum meter signals are logically ANDed, and the vacuum state signal is output to the automatic protection processing module; the compressed air state monitoring module is responsible for the monitoring and logical operation output of all compressed air port states in the equipment. By setting the threshold of the pressure meter, each pressure meter outputs a pressure meter signal, which is logically high when normal and logically low when abnormal. All pressure meter signals are logically ANDed, and the compressed air state signal is output to the automatic protection processing module; the automatic protection processing module is responsible for the logical operation of the safety trigger signal in the equipment and the output of the corresponding control signal; the motion control module is responsible for responding to the instructions of the motion control part in the automatic protection processing module; the light source control module is responsible for responding to the instructions of the light source control part in the automatic protection processing module.

2. The automatic safety protection system for wafer defect detection equipment according to claim 1, characterized in that: It also includes a software monitoring and recording system. In order to monitor and record the equipment status in real time, the system collects all status signals through the digital signal interface module, transmits them to the host computer through the communication interface, records the status and writes them into the system operation log; the status signals include: all compressed air status signals, all vacuum status signals, all door switch signals, all emergency switch signals, bypass switch signals, and output motion emergency stop signals and light source shutdown signals; at the same time, the host computer software side displays these status signals in real time, and performs logical operations on the software side to cross-verify the hardware automatic protection system to ensure accuracy.

3. A protection method for an automatic safety protection system for wafer defect detection equipment according to claim 1 or 2, characterized in that: A threshold is set for the barometer in the compressed air status monitoring module, so that the output signal of the barometer is high under normal circumstances and low under abnormal circumstances; similarly, a threshold is also set for the vacuum gauge in the vacuum status monitoring module, so that the output signal of the vacuum gauge is high under normal circumstances and low under abnormal circumstances; the compressed air status signal and the vacuum status signal are logically ANDed in the automatic protection processing module and output as the pressure gauge status signal, so that when any of the barometer or vacuum gauge is abnormal, the output pressure gauge status signal is low; The safety door status monitoring module connects the safety switches of all equipment micro-environment doors in series, and then connects them in parallel with the bypass switches in the safety door bypass module to output the safety door status signal; When the bypass switch is disconnected, any door body opened will trigger the safety switch of the corresponding door body to disconnect, so that the output safety door status signal becomes low. When the bypass switch is closed, any door body is opened, and the output safety door status signal is still high. In this way, the requirements of the debugging and maintenance process are met; All emergency switches in the emergency response module are connected in series to output emergency switch status signals. When any emergency switch is triggered, the output emergency switch status signal will become low; the safety door status signal and the emergency switch status signal are logically ANDed in the automatic protection processing module to output the switch status signal; in this way, when any door is opened without closing the bypass switch or when the emergency switch is triggered, the switch status signal will become low; the pressure gauge status signal and the switch status signal are logically ANDed and then logically NOTed in the automatic protection processing module, so that when the pressure gauge status signal is low or the switch status signal is low, the motion emergency stop signal becomes high, and at this time all moving parts stop moving according to the set logic; the switch status signal is logically NOTed in the automatic protection processing module, and when the switch status signal is low, the light source shutdown signal becomes high, and all light sources with potential risks are turned off; at this time, the system enters the protection state, and the system will not automatically resume operation until the operator confirms that the safety risk has been eliminated and performs manual intervention.

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