An automated safety protection system and method for wafer defect inspection equipment

Abstract

This invention relates to the field of wafer defect detection technology, specifically to an automatic safety protection system and method for wafer defect detection equipment. It mainly includes a hardware automatic protection system and a software monitoring and recording system. The hardware automatic protection system comprises 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. This system relies entirely on hardware to achieve automatic safety protection functions. The automatic protection process requires no intervention from host computer software or embedded software, ensuring real-time, rapid, and reliable safety protection response. After automatic protection is triggered, the automatic protection system remains in the triggered state until the operator confirms that the safety risk has been eliminated and before manual intervention is performed. Simultaneously, the bypass switch control meets the special application needs of professionally trained equipment maintenance personnel during equipment debugging and maintenance.

Description

Technical Field

[0001] This invention relates to the field of wafer defect detection technology, specifically to an automatic safety protection system and method for wafer defect detection equipment. Background Technology

[0002] In semiconductor device manufacturing processes, it is crucial to detect wafer defects early in the process, promptly identify the causes of defects, and improve the process accordingly. Simultaneously, defects must be marked to prevent defective dies from continuing to be processed, thus avoiding impacts on yield and productivity. Therefore, wafer defect detection is a key method for improving semiconductor device yield and productivity.

[0003] Wafer defect inspection equipment typically operates on an automated process, primarily consisting of wafer loading / unloading and wafer inspection. The wafer loading / unloading process involves vacuum adsorption and high-speed movement, while the wafer inspection process involves vacuum adsorption, high-speed movement, high-power lasers, and ultraviolet or short-wavelength lasers. Currently, inspection equipment is mainly controlled by a host computer or a PLC (Programmable Logic Controller) for safety. The host computer needs to handle multiple tasks, including inspection process control, inspection data collection, status monitoring, and inspection data processing, which may lead to priority conflicts and compromise the timeliness of safety-related status monitoring and process control. Furthermore, the real-time performance and stability of PLCs decrease when handling complex logic. Therefore, inspection equipment requires a fully hardware-based automated protection system to ensure operational safety, provide safety protection for operators, and meet the needs of professionally trained maintenance personnel during equipment commissioning and maintenance. Summary of the Invention

[0004] To address the issue of delayed protection caused by software intervention when using host computers or PLCs for safety control of wafer defect inspection equipment, this invention proposes an automatic safety protection system and method for wafer defect inspection equipment. By integrating multiple safety protection mechanisms and adopting a completely hardware approach, it reliably and effectively prevents potential safety risks, ensuring the safety of operators while also meeting the special application scenarios of professionally trained maintenance personnel.

[0005] This invention is achieved using the following technical solution: an automatic safety protection system for wafer defect detection equipment, comprising 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 cascading and on / off status output of the equipment's microenvironment doors. Each microenvironment door is equipped with a safety switch, and the safety switches of all doors are connected in series through cascading, so that opening any door will change the final output signal status. The safety door bypass module is responsible for the bypass function of the equipment's safety doors. When maintenance personnel need to perform equipment debugging or maintenance during equipment operation, closing the bypass control switch will prevent the automatic protection from being triggered when the equipment's microenvironment door is opened, ensuring the normal progress of debugging and maintenance work. The emergency response module is responsible for triggering the automatic safety protection function when an emergency occurs during equipment use or maintenance, by the operator quickly pressing the emergency switch. Multiple emergency stop switches are connected in series so that pressing any one of them triggers an emergency stop signal. The vacuum status monitoring module is responsible for monitoring the status of all vacuum ports in the equipment and outputting logical operations. By setting the threshold of the vacuum gauges, each vacuum gauge outputs a vacuum gauge signal, which is logically high under normal conditions and logically low under abnormal conditions. All vacuum gauge signals are ANDed to output a vacuum status signal to the automatic protection processing module. The compressed air status monitoring module is responsible for monitoring the status of all compressed air ports in the equipment and outputting logical operations. By setting the threshold of the pressure gauges, each pressure gauge outputs a pressure gauge signal, which is logically high under normal conditions and logically low under abnormal conditions. All pressure gauge signals are ANDed to output a compressed air status signal to the automatic protection processing module. The automatic protection processing module is responsible for the logical operations of safety trigger signals and the output of corresponding control signals in the equipment. The motion control module is responsible for responding to the instructions for motion control in the automatic protection processing module. The light source control module is responsible for responding to the instructions for light source control in the automatic protection processing module.

[0006] The aforementioned automatic safety protection system for wafer defect detection equipment also includes a software monitoring and recording system. To monitor and record the equipment status in real time, the system collects all status signals through a digital signal interface module, transmits them to the host computer via a 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, as well as output motion emergency stop signals and light source shutdown signals. Simultaneously, the host computer software displays these status signals in real time and performs software-side logical operations to cross-verify the hardware automatic protection system to ensure accuracy.

[0007] The aforementioned protection method for an automatic safety protection system for wafer defect inspection equipment involves setting a threshold for the pressure gauges in the compressed air status monitoring module, ensuring a high output signal under normal conditions and a low output signal under abnormal conditions. Similarly, a threshold is set for the vacuum gauges in the vacuum status monitoring module, ensuring a high output signal under normal conditions and a low output signal under abnormal conditions. 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. Thus, if any pressure gauge or vacuum gauge malfunctions, the output pressure gauge status signal will be 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, outputting a safety door status signal. When the bypass switch is open, opening any door will trigger the corresponding door's safety switch to open, causing the output safety door status signal to go low. When the bypass switch is closed, opening any door will still result in a high output safety door status signal, thus satisfying the requirement... To meet the needs during debugging and maintenance, the emergency response module connects all emergency switches in series, outputting an emergency switch status signal. When any emergency switch is triggered, the output emergency switch status signal goes low. The safety door status signal and the emergency switch status signal are logically ANDed in the automatic protection processing module, outputting a switch status signal. Thus, opening any door without closing the bypass switch or triggering an emergency switch will cause the switch status signal to go low. The pressure gauge status signal and the switch status signal are logically ANDed and then NOTed in the automatic protection processing module. When either the pressure gauge status signal or the switch status signal is low, the emergency stop signal goes high, causing all moving parts to stop according to the set logic. The switch status signal is logically NOTed in the automatic protection processing module. When the switch status signal goes low, the light source shutdown signal goes high, shutting off all potentially hazardous light sources. At this point, the system enters a protective state, and will not automatically resume operation until the operator confirms that the safety risk has been eliminated and performs manual intervention.

[0008] This invention discloses an automatic safety protection system for wafer defect inspection equipment, primarily comprising a hardware automatic protection system and a software monitoring and recording system. 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. The system relies entirely on hardware to achieve automatic safety protection functions. No host computer software or embedded software intervention is required during the automatic protection process, ensuring real-time, rapid, and reliable safety protection response. After automatic protection is triggered, the automatic protection system remains in the triggered state until the operator confirms that the safety risk has been eliminated and no manual intervention is performed. Simultaneously, the bypass switch control meets the special application needs of professionally trained equipment maintenance personnel during equipment debugging and maintenance. Attached Figure Description

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

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

[0011] Figure 3 This is a schematic diagram of the signal connection of the software monitoring system of the present invention. Detailed Implementation

[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 cascading and opening / closing status output of the equipment's micro-environment doors. Each door in the equipment's micro-environment is equipped with a highly reliable safety switch. By cascading, all the safety switches on all doors are connected in series, ensuring that opening any one door will change the final output signal status.

[0015] The safety door bypass module is responsible for the bypass function of the equipment's safety doors. When professionally trained maintenance personnel need to perform equipment debugging or maintenance during equipment operation, they can close the bypass control switch. At this time, opening the equipment's 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 automatic safety protection functions when an emergency occurs during equipment use or maintenance. Operators can quickly press the emergency switch to activate these functions. The emergency switch is a highly reliable, long-life, normally closed switch with a self-locking and resettable design. Some wafer defect detection equipment is large and requires multiple emergency switches to ensure that operators can quickly press the nearest available switch in case of an emergency. In this case, multiple emergency switches are connected in series so that pressing any one of them will 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 logical operations. By setting the threshold of the vacuum gauges, each vacuum gauge outputs a vacuum status signal. Under normal conditions, the signal is logic high (high level output when the vacuum pressure value exceeds the threshold), and under abnormal conditions, the signal is logic low (low level output when the vacuum pressure value does not exceed the threshold).

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

[0019] The automatic protection processing module is responsible for the logical operations of safety trigger signals and the output of corresponding control signals in the equipment. The logic operation part of the module adopts a completely hardware approach to achieve fast response and highly reliable automatic protection signal output.

[0020] The motion control module is responsible for responding to commands from the automatic protection processing module regarding the motion control section. For moving parts without wafers, it is required to stop the movement at maximum deceleration. For high-speed moving parts with wafers, it is required to stop the movement smoothly to avoid wafer damage.

[0021] The light source control module is responsible for responding to the automatic protection module's control over the light source. For high-power lasers and ultraviolet or short-wavelength laser sources, when the automatic protection is triggered, these potentially harmful light sources are quickly shut down.

[0022] Figure 2 The system signal connection diagram is shown in the figure:

[0023] The barometer is set with an appropriate threshold so that the output signal is high under normal conditions and low under abnormal conditions. Similarly, the vacuum gauge is also set with an appropriate threshold so that the output signal is high under normal conditions and low under abnormal conditions.

[0024] All pressure gauge output signals are ANDed to produce a compressed air status signal. This ensures that if any pressure gauge is abnormal, the output compressed air status signal will be low. Similarly, all vacuum gauge output signals are ANDed to produce a vacuum status signal. This ensures that if any vacuum gauge is abnormal, the output vacuum status signal will be low. The compressed air and vacuum status signals are then ANDed in the automatic protection processing module to produce pressure gauge status signals. This ensures that if any pressure gauge or vacuum gauge is abnormal, the output pressure gauge status signal will be low.

[0025] All safety switches for the micro-environment doors of the equipment are connected in series, and then in parallel with a bypass switch, outputting a safety door status signal. When the bypass switch is open, opening any door will trigger the corresponding door's safety switch to open, causing the output safety door status signal to go low. When the bypass switch is closed, opening any door will still result in a high output safety door status signal. This meets the special requirements during commissioning and maintenance. All emergency switches are connected in series, outputting an emergency switch status signal. When any emergency switch is triggered, the output emergency switch status signal will go low. The safety door status signal and the emergency switch status signal are logically ANDed in the automatic protection processing module to output a switch status signal. Thus, opening any door without closing the bypass switch, or triggering an emergency switch, will cause the switch status signal to go low.

[0026] The pressure gauge status signal and the switch status signal are logically ANDed and then logically NOTed. When either the pressure gauge status signal or the switch status signal is low, the emergency stop signal goes high, causing all moving parts to stop rapidly or at a certain deceleration according to pre-set logic. When the switch status signal is low, the light source shutdown signal goes high, rapidly shutting off all potentially hazardous light sources. At this point, the system enters a protective state and will not automatically resume operation until the operator confirms that the safety risk has been eliminated and intervenes manually.

[0027] Software Monitoring and Recording System: To monitor and record equipment status in real time, the system collects all status signals through a digital signal interface module, transmits them to the host computer via a communication interface, records the status, and writes them to the system operation log. Status signals include: all pressure gauge signals, all vacuum gauge signals, all door open / close signals, all emergency switch signals, bypass switch signals, as well as output motion emergency stop signals and light source shutdown signals. Simultaneously, the host computer software displays these status signals in real time and performs software-based logical calculations to cross-verify the hardware automatic protection system to ensure accuracy.

[0028] The beneficial effects of this invention are:

[0029] 1) This invention proposes an automatic security protection system that is entirely implemented in hardware. The automatic protection process does not require the intervention of host computer software or embedded software, ensuring real-time and rapid protection response.

[0030] 2) This 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 cessation of different risk sources according to the set trigger logic through hardware logic operations.

[0031] 3) This invention proposes a safety gate bypass method to meet the special operational requirements during the debugging and maintenance of wafer defect detection equipment.

Claims

1. An automatic safety protection system for wafer defect inspection equipment, characterized in that: The system includes a hardware-based automatic protection system, comprising 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 cascading and on / off status output of the equipment's micro-environment doors. Each micro-environment door is equipped with a safety switch, and these switches are connected in series to ensure that opening any door will change the final output signal status. The safety door bypass module is responsible for the bypass function of the equipment's safety doors. When maintenance personnel need to perform equipment debugging or maintenance during operation, closing the bypass control switch will prevent the automatic protection from being triggered when opening the equipment's micro-environment door, ensuring the normal progress of debugging and maintenance work. The emergency response module is responsible for triggering automatic safety protection functions when an emergency occurs during equipment use or maintenance. Multiple emergency stop switches are connected in series, ensuring that pressing any one of them triggers an emergency stop signal. The vacuum status monitoring module monitors the status of all vacuum ports in the equipment and outputs logical operations. By setting thresholds for vacuum gauges, each gauge outputs a signal: logical high for normal operation and logical low for abnormal operation. All vacuum gauge signals are ANDed to output a vacuum status signal to the automatic protection processing module. The compressed air status monitoring module monitors the status of all compressed air ports in the equipment and outputs logical operations. By setting thresholds for pressure gauges, each pressure gauge outputs a signal: logical high for normal operation and logical low for abnormal operation. All pressure gauge signals are ANDed to output a compressed air status signal to the automatic protection processing module. The automatic protection processing module handles the logical operations of safety trigger signals and outputs corresponding control signals. The motion control module responds to commands from the automatic protection processing module regarding motion control. The light source control module responds to commands from the automatic protection processing module regarding light source control.

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 a 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 open / close signals, all emergency switch signals, bypass switch signals, as well as output motion emergency stop signals and light source turn-off signals. At the same time, the host computer software displays these status signals in real time and performs software-side logical operations to cross-verify the hardware automatic protection system to ensure accuracy.

3. The protection method of an automatic safety protection system for wafer defect detection equipment as described in claim 1 or 2, characterized in that: A threshold is set for the pressure gauge in the compressed air status monitoring module so that the pressure gauge output signal is high under normal conditions and low under abnormal conditions. Similarly, a threshold is set for the vacuum gauge in the vacuum status monitoring module so that the vacuum gauge output signal is high under normal conditions and low under abnormal conditions. 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. In this way, 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 micro-environment 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 open, opening any door will trigger the corresponding door's safety switch to open, causing the output safety door status signal to go low. When the bypass switch is closed, opening any door will still cause the output safety door status signal to go high, thus meeting the requirements during commissioning and maintenance. In the emergency response module, all emergency switches are connected in series, outputting an emergency switch status signal. When any emergency switch is triggered, the output emergency switch status signal goes low. The safety door status signal and the emergency switch status signal are logically ANDed in the automatic protection processing module, outputting a switch status signal. Thus, opening any door without closing the bypass switch or triggering an emergency switch will cause the switch status signal to go low. The pressure gauge status signal and the switch status signal are logically ANDed and then logically NOTed in the automatic protection processing module. When either the pressure gauge status signal or the switch status signal is low, the emergency stop signal goes high, at which point all moving parts stop according to the set logic. The switch status signal is logically NOTed in the automatic protection processing module; when the switch status signal goes low, the light source shutdown signal goes high, shutting off all potentially hazardous light sources. At this point, the system enters a protective state, and will not automatically resume operation until the operator confirms that the safety risk has been eliminated and performs manual intervention.

Images