Reticle inspection system and method

Abstract

The disclosure provides a photomask detection system and method, relating to the technical field of semiconductors. The photomask detection system comprises a photomask thickness measuring device comprising a plurality of sensor modules arranged side by side, for measuring the thickness of the photomask; a barcode reading device is arranged opposite the photomask thickness measuring device, for reading the barcode on the photomask to obtain the thickness information of the photomask; the calibration device comprises a calibration rod and an electromagnet, the calibration rod comprises a calibration rod and a calibration base, the electromagnet is arranged corresponding to the bottom of the calibration base, and the calibration device is used for calibrating the barcode reading device. The photomask detection system provided by the disclosure can prevent the photomask with abnormal thickness from entering the machine when the photomask barcode reading is abnormal or a new photomask enters the machine, and can protect the machine device. By arranging the calibration device, automatic calibration of the barcode reading device can be realized, the machine updating time is saved, and the calibration rate is improved.

Description

Technical Field

[0001] This disclosure relates to the field of semiconductor technology, and more specifically, to a photomask inspection system and method. Background Technology

[0002] In semiconductor fabrication processes, photolithography is a crucial step in semiconductor device manufacturing. Photolithography involves using exposure and development to etch a patterned structure onto a photoresist, and then transferring the pattern from the photomask to a substrate through etching. Photolithography equipment is an indispensable piece of equipment in the photolithography process and is the core equipment for producing large-scale integrated circuits. The normal operation of photolithography equipment is a prerequisite for ensuring the semiconductor process.

[0003] In existing photolithography equipment, before the photomask enters the photomask storage unit, the machine's barcode reader reads the barcode on the photomask to obtain relevant information. This information is used to determine the photomask's access rights. However, when the machine's barcode reader malfunctions, abnormal photomask barcode reading can occur, causing some photomask-related settings in the equipment to fail, leading to photomask damage or even equipment destruction. Furthermore, in existing technology, when the machine's barcode reader malfunctions, the equipment stops operating for calibration, usually manually, resulting in a low calibration rate and long calibration time.

[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and to provide a photomask inspection system and method.

[0006] Other features and advantages of this disclosure will become apparent from the following detailed description, or may be learned in part from practice of this disclosure.

[0007] According to one aspect of this disclosure, a photomask detection apparatus is provided, the apparatus comprising:

[0008] A photomask thickness measuring device, comprising multiple sensor modules arranged side by side, the sensor modules being used to measure the thickness of the photomask;

[0009] A barcode reading device is provided, which is positioned opposite the photomask thickness measuring device. The barcode reading device is used to read the barcode on the photomask to obtain the thickness information of the photomask.

[0010] A calibration device is provided, comprising a calibration rod and an electromagnet. The calibration rod includes a calibration arm and a calibration base. The electromagnet is disposed correspondingly to the bottom of the calibration base. The calibration device is used to calibrate the barcode reader.

[0011] In some embodiments of this disclosure, based on the foregoing scheme, the calibration rod is connected to the top surface of the calibration base.

[0012] In some embodiments of this disclosure, based on the foregoing scheme, the barcode reading device further includes a calibration button, and the calibration rod calibrates the barcode reading device by contacting the calibration button.

[0013] In some embodiments of this disclosure, based on the foregoing scheme, the photomask detection system further includes a power supply, which employs a voltage regulator chip. The power supply provides voltage to the electromagnet, causing the electromagnet to generate polarity after being energized.

[0014] In some embodiments of this disclosure, based on the foregoing scheme, the diameter of the calibration rod is less than or equal to the diameter of the calibration button.

[0015] In some embodiments of this disclosure, based on the foregoing scheme, both the calibration base and the electromagnet are circular in shape, and the diameter of the calibration base is equal to the diameter of the electromagnet.

[0016] In some embodiments of this disclosure, based on the foregoing scheme, the polarity of the calibration base is the same as the polarity of the electromagnet after it is energized.

[0017] In some embodiments of this disclosure, based on the foregoing scheme, the calibration base and the electromagnet are connected in a non-contact manner.

[0018] In some embodiments of this disclosure, based on the foregoing scheme, the calibration device further includes a spring that passes through the calibration rod.

[0019] In some embodiments of this disclosure, based on the foregoing scheme, the length of the spring is equal to the length of the calibration rod.

[0020] In some embodiments of this disclosure, based on the foregoing scheme, the calibration device further includes a fixed baffle with a through hole, and the calibration rod passes through the through hole.

[0021] In some embodiments of this disclosure, based on the foregoing scheme, the fixing baffle is disposed on the top of the calibration rod.

[0022] In some embodiments of this disclosure, based on the foregoing scheme, the sensor module includes a reflective photoelectric sensor.

[0023] According to another aspect of this disclosure, a photomask detection method is provided, the method comprising:

[0024] A photomask thickness measuring device is provided, the photomask thickness measuring device includes multiple sensor modules arranged side by side, and the thickness of the photomask is measured by the sensor modules;

[0025] A barcode reading device is provided, which reads the barcode on the photomask and calls a pre-set database to determine whether the barcode is included in the database;

[0026] A calibration device is provided, which includes a calibration rod and an electromagnet. The calibration rod includes a calibration arm and a calibration base. The electromagnet is disposed corresponding to the bottom of the calibration base. The barcode reader is calibrated using the calibration device.

[0027] In some embodiments of this disclosure, based on the foregoing scheme, determining whether the barcode is included in the database includes:

[0028] If the database does not contain the barcode of the photomask, then the photomask thickness measuring device is activated to measure the thickness of the photomask and obtain the maximum thickness value of the photomask.

[0029] If the maximum thickness of the photomask is less than a preset threshold, the photomask is allowed to enter the machine.

[0030] In some embodiments of this disclosure, based on the aforementioned scheme, if the maximum thickness of the photomask is greater than or equal to a preset threshold, the photomask is prohibited from entering the machine, and permission information is set for the photomask, updating the barcode information of the photomask and the permission information to the database.

[0031] In some embodiments of this disclosure, based on the foregoing scheme, the following further methods are included:

[0032] If the barcode reader fails to read the barcode on the photomask, the calibration device is activated to calibrate the barcode reader. After calibration, the barcode reader will reread the barcode on the photomask.

[0033] In some embodiments of this disclosure, based on the foregoing scheme, calibrating the barcode reading device includes:

[0034] Turn on the power supply to energize the electromagnet;

[0035] When energized, the electromagnet pushes the calibration base to control the movement of the calibration rod, causing the tip of the calibration rod to press the calibration button on the barcode reader to calibrate the barcode reader;

[0036] After maintaining the calibration for the predetermined time, disconnect the power supply to de-energize the electromagnet, and the calibration rod will reset under the action of the spring.

[0037] In some embodiments of this disclosure, based on the foregoing scheme, the following further methods are also included:

[0038] If the barcode reading device fails to read the barcode on the photomask, the photomask thickness measuring device is activated to measure the thickness of the photomask.

[0039] In some embodiments of this disclosure, based on the foregoing scheme, measuring the thickness of the photomask using the sensor module includes:

[0040] The sensor module measures the distance between the sensor module and the robotic arm to obtain a first distance;

[0041] The robotic arm moves the photomask so that it passes through the illumination area of ​​the photomask thickness measuring device. The sensor module measures the distance between the sensor module and the top surface of the photomask to obtain a second distance.

[0042] The difference between the first distance and the second distance is calculated, and the difference is the thickness of the photomask.

[0043] This disclosure provides a photomask inspection system. On the one hand, by setting a photomask thickness measuring device in the system, the thickness of the photomask can be measured when the barcode reading device reads the photomask barcode abnormally or when a new photomask enters the machine. This prevents the thickness of the photomask from exceeding the limit requirements of the machine's photomask storage unit, prevents the photomask from accidentally entering the machine and damaging the machine, and protects both the photomask and the machine.

[0044] On the other hand, by setting up a barcode reader calibration device in the system, the barcode reader can be automatically calibrated when it malfunctions in reading the photomask barcode, eliminating the need for manual operation, shortening the machine update time, and improving the device calibration rate.

[0045] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0046] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure. It is obvious that the drawings described below are merely some embodiments of this disclosure, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0047] Figure 1 This is a schematic diagram of the structure of a photomask detection system according to an exemplary embodiment of the present disclosure.

[0048] Figure 2 This is a top view of a photomask detection system according to an exemplary embodiment of the present disclosure.

[0049] Figure 3 This is a schematic diagram of a photomask thickness measuring device according to an exemplary embodiment of the present disclosure.

[0050] Figure 4 This is another measurement schematic diagram of a photomask thickness measuring device in an exemplary embodiment of the present disclosure.

[0051] Figure 5 This is a schematic diagram of the connection relationship of a calibration device in an exemplary embodiment of the present disclosure.

[0052] Figure 6 This is a schematic diagram of the structure of a calibration device according to an exemplary embodiment of the present disclosure.

[0053] Figure 7 This is a top view of a fixed baffle according to an exemplary embodiment of the present disclosure.

[0054] Figure 8 This is a schematic flowchart of a photomask detection method according to an exemplary embodiment of the present disclosure.

[0055] Figure 9 This is another flowchart illustrating a photomask detection method according to an exemplary embodiment of the present disclosure.

[0056] Figure 10 This is a flowchart illustrating the operation of a calibration apparatus according to an exemplary embodiment of the present disclosure.

[0057] Figure 11 This is a flowchart illustrating the operation of a photomask thickness measuring device according to an exemplary embodiment of the present disclosure.

[0058] The reference numerals in the attached figures are explained as follows:

[0059] 1: Photomask thickness measuring device; 2: Barcode reading device; 3: Photomask;

[0060] 4: Machine base; 41: Machine base crossbeam; 42: Machine base base;

[0061] 21: Calibration device; 22: Barcode reader; 23: Signal processing circuit;

[0062] 24: Control system; 210: Electromagnet; 211: Calibration rod; 2111: Calibration base;

[0063] 2112: Calibration rod; 212: Spring; 213: Fixing baffle; 2131: Through hole;

[0064] 214: Calibration button. Detailed Implementation

[0065] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore detailed descriptions of them will be omitted. Furthermore, the drawings are merely illustrative of this disclosure and are not necessarily drawn to scale.

[0066] Although relative terms such as "up" and "down" are used in this specification to describe the relative relationship of one component of an icon to another, these terms are used only for convenience, such as according to the orientation of the examples shown in the accompanying drawings. It is understood that if the device of the icon is flipped upside down, the component described as "up" will become the component described as "down." When a structure is "up" of another structure, it may mean that the structure is integrally formed on the other structure, or that the structure is "directly" mounted on the other structure, or that the structure is "indirectly" mounted on the other structure through another structure.

[0067] The terms “a,” “one,” “the,” “the,” and “at least one” are used to indicate the presence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended inclusion and to mean that there may be other elements / components / etc. in addition to the listed elements / components / etc.; the terms “first,” “second,” and “third,” etc., are used only as markers and are not a limitation on the number of objects.

[0068] Photolithography equipment is one of the most important processing equipment in the integrated circuit chip manufacturing process. It is used to transfer the design pattern of the chip from the photomask (i.e., mask) onto the photoresist on the silicon wafer surface through exposure. In the process of completing a chip manufacturing, photomasks of different sizes are usually required to transfer different design patterns onto the silicon wafer. As the critical dimensions of integrated circuit chips become smaller and smaller, the manufacturing cost of photomasks becomes larger and larger. Therefore, in the process of using photomasks in photolithography equipment, it is necessary to identify photomasks of different sizes to ensure that the size of the photomask meets the size requirements of the photolithography equipment. This is to ensure that the photomask is not damaged due to its excessive size when it enters the photomask storage unit of the photolithography equipment.

[0069] In lithography equipment, malfunctions of the barcode reader when reading photomask barcodes are common. In such cases, the barcode reader may display an error indicating an incorrect number of digits read. Some photomasks, due to the presence of additional mirroring or patterning devices, are significantly thicker than standard photomasks. If the photomask thickness exceeds the thickness of the equipment's photomask storage unit, the malfunctioning barcode reader can cause some settings on the lithography equipment to fail, leading to collisions between the equipment and the photomask, resulting in damage to both. For example, when the barcode reader malfunctions, the number of digits read from the photomask barcode may change. This can cause the equipment's access permissions to the photomask to become invalid, allowing the photomask of that type to enter the machine even if its thickness exceeds the equipment's maximum allowable thickness, thus damaging the photomask.

[0070] In addition, when the barcode reader malfunctions in reading the photomask barcode, it is necessary to stop the machine and calibrate the barcode reader. Currently, manual calibration is usually used, but this calibration method is slow. It requires judgment and calibration after the device malfunctions in reading the barcode. Furthermore, this calibration method cannot automatically calibrate the device and confirm the calibration results, resulting in a long machine update cycle and slow confirmation of calibration results.

[0071] Therefore, this disclosure provides a photomask inspection system that can both measure the thickness of the photomask and automatically calibrate the barcode reading device.

[0072] This disclosure provides a photomask inspection system. Figure 1 This is a schematic diagram of the structure of a photomask detection system according to an exemplary embodiment of the present disclosure, as shown below. Figure 1 As shown, the photomask inspection system includes: a photomask thickness measuring device 1, a barcode reading device 2, and a calibration device.

[0073] The photomask thickness measuring device 1 includes multiple sensor modules arranged side by side, which are used to measure the thickness of the photomask 3.

[0074] In embodiments of this disclosure, such as Figure 2 As shown, combined with Figure 1 and Figure 2A photomask thickness measuring device 1 is installed at the entrance of the lithography equipment 4. The photomask thickness measuring device 1 is installed on the crossbeam 41 of the lithography equipment 4 at the entrance. The photomask thickness measuring device 1 is composed of multiple sensor modules. Each sensor module may also contain multiple sensors. The sensors can be reflective photoelectric sensors, ultrasonic ranging sensors, laser ranging sensors, or infrared ranging sensors. This disclosure does not limit the specific type of sensor, but it needs to meet the specific needs of ranging and not affect the normal operation of the lithography equipment. The number of sensor modules can be 5 or more. The specific number can be selected according to the width of the photomask or the structure of the lithography equipment.

[0075] In some embodiments, the ranging area of ​​each sensor on the photomask 3 is fixed. The total scanning length of multiple sensor modules arranged side by side needs to be greater than or equal to the width of the photomask 3 to ensure that the scanning area of ​​the sensor module covers the entire area of ​​the photomask 3. For example, if the width of the photomask 3 is A, the width of the photomask 3 that a single sensor can measure is a, and the number of sensors is N, then the width of the photomask 3 A≤N*a. The distribution interval of the sensor modules can be determined according to the measuring area of ​​the sensor modules.

[0076] When a new photomask 3 enters the lithography equipment or the barcode reader malfunctions in reading the photomask barcode, the photomask thickness measuring device 1 in the photomask inspection system is activated. Multiple sensor modules in the photomask thickness measuring device 1 scan the entire area of ​​the new photomask 3. The direction of movement of the photomask 3 within the photomask inspection system is as follows: Figure 1 The direction indicated by the middle arrow determines the thickness corresponding to each point within the area of ​​photomask 3. The thickness of each point is compared with the maximum allowable photomask thickness of the machine to determine whether a new photomask 3 can enter the machine. If the thickness of each point of the new photomask 3 is less than or equal to the maximum allowable photomask thickness of the machine, the new photomask 3 is allowed to enter the machine. If one or more points in the new photomask 3 have a thickness greater than the maximum allowable photomask thickness of the machine, the photomask 3 is prohibited from entering the machine, and its thickness information is updated to a preset database. Simultaneously, an access restriction is set for this prohibited photomask. For example, if the maximum allowable photomask thickness of the machine's photomask storage unit is 50mm, the photomask thickness measuring device 1 will detect the thickness of any new photomask entering it. If the thickness of the new photomask is ≤50mm, the new photomask is allowed to enter the machine. If the thickness of the new photomask is >50mm, the new photomask is prohibited from entering the machine, and its thickness information is updated to the machine's database. An access restriction is also set for this prohibited photomask.

[0077] Figure 3 and Figure 4 This is a schematic diagram of a photomask thickness measuring device according to an exemplary embodiment of the present disclosure, combined with... Figure 3 and Figure 4 The working principle of the photomask thickness measuring device is explained below:

[0078] In some embodiments, the photomask is mounted on the photomask clamping robotic arm 42, and the photomask 3 can be moved within the machine tool by the robotic arm 42. The photomask thickness measuring device 1 is set at a fixed position on the machine tool crossbeam 1. When no photomask 3 enters the machine tool, the photomask thickness measuring device 1 is activated, and the robotic arm 42 moves along a preset path. The distance S1 between the photomask thickness measuring device 1 and the robotic arm is measured by the sensor in the photomask thickness measuring device 1 when no photomask is placed. When the robotic arm 42 clamps the photomask 3 and enters the scanning area of ​​the photomask thickness measuring device 1, the sensor in the photomask thickness measuring device 1 can measure the distance S2 between each point on the top surface of the photomask 3 and the device. Then, the thickness value H of each point on the photomask is H = S2 - S1.

[0079] The photomask inspection system can generate a photomask thickness map based on the thickness data of the photomask 3 detected by the photomask thickness measurement device 1. The maximum thickness of the photomask 3 can be displayed intuitively through the photomask thickness map. At the same time, the photomask inspection system can update the thickness information of the photomask 3 to a pre-set database, set corresponding permissions for subsequent machine operation, and set access prohibition permissions for photomasks that exceed the maximum allowable photomask height of the machine, prohibiting photomasks with a height exceeding the allowable height from entering the machine.

[0080] The photomask inspection system includes a barcode reading device 2 and a calibration device.

[0081] The barcode reading device 2 and the photomask thickness measuring device 1 are set opposite each other at the machine entrance. The barcode reading device 2 is used to read the barcode on the photomask 3 to obtain the thickness information of the photomask 3.

[0082] In some embodiments, the calibration device includes a calibration rod and an electromagnet. The calibration rod includes a calibration arm and a calibration base. The calibration arm is vertically connected to the top surface of the calibration base, and the electromagnet is disposed at the bottom of the calibration base. The calibration device is used to calibrate a barcode reader.

[0083] Figure 5 This is a schematic diagram of the connection relationship of a calibration device in an exemplary embodiment of the present disclosure, as shown below. Figure 5 As shown, the calibration device 21 is connected to the barcode reading device 2. The barcode reading device 2 includes a barcode reader 22, a signal processing circuit 23, and a control system 24. The barcode reader 22 obtains relevant information about the photomask 3, including the thickness information of the photomask 3, by reading the barcode on the photomask 3. The barcode reader 22 sends the above information to the signal processing circuit 23. The signal processing circuit 23 sends the received information to the control system 24 again. The control system 24 operates the barcode reader 22 by sending relevant instructions.

[0084] The calibration device 21 is installed on the barcode reader 22 in the barcode reading device 2 and connected to the signal processing circuit 23. When the barcode reader 22 reads the photomask barcode abnormally, it can transmit the abnormal reading signal to the signal processing circuit 23. Then, the control system 24 will activate the calibration device 21 and feed the information back to the signal processing circuit 23. The signal processing circuit 23 controls the calibration device 21 to calibrate the barcode reader 22. After one calibration is completed, the barcode reader 22 rereads the photomask barcode to verify the calibration result of the calibration device 21. If the barcode reader 22 still reads the barcode abnormally, the calibration device 21 continues to calibrate until the barcode reader 22 can read the barcode of the photomask 3 normally.

[0085] In some embodiments, such as Figure 6 As shown, the calibration device 21 includes a calibration rod 211 and an electromagnet 210. The calibration rod 211 includes a calibration bar 2112 and a calibration base 2111. The calibration bar 2112 is vertically arranged on the calibration base 2111, and the electromagnet 210 is arranged at the bottom of the calibration base 2111.

[0086] The barcode reader 2 also includes a calibration button 214, which can be used to calibrate the barcode reader 2 by pressing the calibration button 214. The calibration rod 2112 in the calibration device 21 can be cylindrical, and its diameter must be less than or equal to the surface area of ​​the calibration button 214 to ensure that the top of the calibration rod 2112 can be pressed to calibrate the device. The calibration base 2111 is a circular plate, and is perpendicularly connected to the calibration rod 2112. 1. It has polarity, and the polarity of the calibration base 2111 is the same as the polarity of the electromagnet 210 after it is energized; the electromagnet 210 in the calibration device 21 has a circular structure, and the diameter of the electromagnet 210 is equal to the diameter of the calibration base 2111. The electromagnet 210 is located below the bottom of the calibration base 2111 and is connected to the calibration base 2111 in a non-contact manner; the calibration device 21 also includes a spring 212, which passes through the rod of the calibration rod 2112, and the natural length of the spring 212 is equal to the length of the calibration rod 2112.

[0087] The calibration device 21 also includes a fixed baffle 213, such as Figure 7 As shown, a through hole 2131 is provided on the fixed baffle 213, and the calibration rod 2112 passes through the through hole 2131 of the fixed baffle 213. The fixed baffle 213 is located on the upper part of the calibration rod 2112 and is located on the barcode reading device 2 to provide a fixed position for the calibration device 21.

[0088] It should be noted that the calibration base 2111 in the calibration device 21 of this disclosure is shaped to match the electromagnet 210. The shapes of the calibration base 2111 and the electromagnet 210 can both be circular or other shapes, such as rectangular or square. The shape of the calibration base can be determined according to the shape of the selected electromagnet 210, and this disclosure does not make specific limitations. The calibration base 2111 and the calibration rod 2112 can be integrally formed, welded, or riveted. This disclosure does not make specific limitations on the connection relationship between the two. One end of the spring 212 can be fixed to the calibration base 2111 or not. The specific connection method of the spring 212 can be determined according to the actual use requirements. The calibration device 21 can be integrated into the barcode reading device 2 or set outside the barcode reading device 2, and can be selected according to the actual design requirements of the device.

[0089] In some specific embodiments, the calibration rod 2112 can be a cylindrical rod with a length of 2-10cm and a diameter of 4-12mm. For example, the calibration rod 2112 can be a cylindrical rod with a length of 6cm and a diameter of 8mm; the calibration base 2111 can be a circular magnet with a diameter of 2-8cm. For example, the calibration base 2111 can be a circular magnet with a diameter of 5cm; the spring 212 can be a spring with a length of 30-90mm and a diameter of 20-80mm. For example, the spring 212 can be a spring with a length of 60mm and a diameter of 50mm; the fixing baffle 213 can... A plate-shaped structure with through holes 2131 and a length of 20-60mm and a width of 20-60mm is selected, and the diameter of the through holes 2131 of the fixing baffle 213 is greater than or equal to 8mm. For example, the fixing baffle 213 can be a plate-shaped structure with through holes and a length of 40mm and a width of 40mm. The electromagnet 210 can be a circular electromagnet with a voltage of 24V, a stroke of 0-6mm, a thrust of 5-10N, a holding force of ≥35N, a power of 38.5W or 22.2W, a current of 1.6A or 0.92A, a resistance of 15 ohms or 26 ohms, and a working cycle of 0-50S. The photomask inspection system includes a power supply, which uses a voltage regulator chip. The power supply can be a stable and uninterrupted power supply output from an electromagnet, and can reasonably match the voltage and power output. The power supply can use a voltage regulator chip, such as a 24V voltage regulator chip, which can output a stable and uninterrupted 24V power supply. However, the power supply type disclosed herein is not limited to this and can be determined according to actual usage needs.

[0090] The calibration of the barcode reader is explained below:

[0091] When the barcode reader 2 malfunctions in reading the photomask barcode, the calibration device 21 is activated to calibrate the barcode reader 2. The electromagnet 210 in the calibration device 21 is energized, giving it the same polarity as the calibration base 2111. Due to the principle of like poles repelling, the electromagnet 210 pushes the calibration base 2111 forward, causing the spring 212 to deform elastically. The calibration base 2111 then pushes the calibration rod 2112 to activate the calibration button 214 for calibration. After the calibration rod 2112 holds the calibration button 214 pressed for a certain period, the power is disconnected. This causes the electromagnet 210 to lose power and its polarity, and the like-pole repulsion between the electromagnet 210 and the calibration base 2111 disappears. Due to the elastic deformation of the spring 212, the calibration rod 211 returns to its initial position, completing one calibration of the barcode reader 2. After calibration, the barcode reader 2 rereads the barcode on the photomask with abnormal barcode reading to verify whether the calibration of the barcode reader 2 was successful. If the calibration of the barcode reader 2 fails, the above process is repeated for recalibration until the barcode reader 2 can read the barcode normally, and the calibration process ends.

[0092] It should be noted that in the aforementioned calibration device 21, the electromagnet 210 is disposed at the bottom of the calibration rod 211. The electromagnet 210 and the calibration rod 211 have the same polarity. Due to the principle of like poles repelling each other, the electromagnet 210 can push the bottom of the calibration rod 211 forward. Alternatively, the calibration device 21 can be modified so that the electromagnet 210 is disposed at the top of the calibration rod 211, with the electromagnet 210 and the top of the calibration rod 211 having different polarities. Due to the principle of opposite poles attracting each other, the electromagnet 210 can attract the calibration rod 211 forward. This disclosure includes, but is not limited to, the aforementioned calibration device 21 and its modified forms.

[0093] Specifically, the calibration lever 2112 maintains the calibration button pressed for a certain period of time. For example, this period of time can be set to 1-5 seconds, or it can be 3 seconds. However, this disclosure does not specifically limit the period of time. The duration of maintaining the calibration button 214 pressed can be determined according to specific usage requirements. When the electromagnet 210 pushes the calibration base 2111 forward, in some embodiments, the calibration base 2111 moves forward by 2-10 mm. For example, the forward movement distance can be 5 mm. This distance is related to the distance between the calibration device 21 and the barcode reader 22. If the calibration device 21 is far from the barcode reader 22, the forward movement distance of the calibration base 2111 can be greater than 5 mm. If the calibration device 21 is close to the barcode reader 22, the forward movement distance of the calibration base 2111 can be less than 5 mm.

[0094] In some embodiments, in addition to rereading the barcode, the verification of the device calibration result can also be achieved by activating the photomask thickness measuring device 1 to verify the thickness of the photomask and comparing it with the thickness information of the photomask in the preset database. If the thickness error of the photomask is within a certain range, it can be further determined whether the calibration result is successful.

[0095] In the photomask inspection system disclosed herein, a photomask thickness measuring device 1 and a barcode reading device 2 are installed in the system. The photomask thickness measuring device 1 can measure the thickness of the photomask 3 by setting multiple sensor modules, preventing photomasks exceeding the allowable thickness from entering the machine, thus ensuring the normal operation of the photomask 3 and the machine. The barcode reading device 2 is equipped with a calibration device 21, which can automatically calibrate the device when the barcode reading device 2 reads an abnormal barcode, shortening the machine update time, and the calibration speed is fast and the calibration accuracy is high.

[0096] Another aspect of this disclosure provides a photomask detection method, such as... Figure 8 As shown, the method includes:

[0097] S101: Provide a photomask thickness measuring device, the photomask thickness measuring device including multiple sensor modules arranged side by side, and use the sensor modules to measure the thickness of the photomask;

[0098] S102: Provide a barcode reading device, use the barcode reading device to read the barcode on the photomask, and call a pre-set database to determine whether the barcode is included in the database;

[0099] S103: Provide a calibration device, the calibration device including a calibration rod and an electromagnet, the calibration rod including a calibration lever and a calibration base, the electromagnet being disposed correspondingly to the bottom of the calibration base, and using the calibration device to calibrate the barcode reading device.

[0100] The photomask detection method is as follows: A photomask thickness measuring device is provided, comprising multiple sensor modules arranged side-by-side, which are used to measure the thickness of the photomask; a barcode reading device is provided, which reads the barcode on the photomask and retrieves a pre-set database to determine whether the barcode is included in the database; a calibration device is provided, comprising a calibration rod and an electromagnet, the calibration rod comprising a calibration lever and a calibration base, the electromagnet being correspondingly positioned at the bottom of the calibration base, and the barcode reading device being calibrated using the calibration device.

[0101] In step S102, determining whether the barcode is included in the database, such as... Figure 9 As shown, it includes the following steps:

[0102] Step S1011: If the database does not contain the barcode of the photomask, then start the photomask thickness measuring device to measure the thickness of the photomask and obtain the maximum thickness value of the photomask;

[0103] Step S1012: If the maximum thickness of the photomask is less than a preset threshold, the photomask is allowed to enter the machine.

[0104] Step S1013: If the maximum thickness of the photomask is greater than or equal to a preset threshold, the photomask is prohibited from entering the machine, and permission information is set for the photomask. The barcode information of the photomask and the permission information are updated to the database.

[0105] In step S1013, permission information is set for the photomask. The permission information for the photomask includes the permission to prohibit the photomask from entering the machine, and may also include other information related to the photomask's permissions. This disclosure does not make specific limitations. The thickness information and permission information of the photomask are updated to the database. After the machine obtains the photomask information, it can call the information in the database and compare the photomask information with the information in the database. If the photomask information is the information already entered in the database, the photomask can be quickly prohibited from entering the machine. This method of comparing the database and the photomask information can quickly determine the permissions of the photomask and shorten the time for determining the permissions of the photomask.

[0106] Furthermore, the information in the database disclosed herein is not limited to a set of information on photomasks that are prohibited from entering the machine. The information in the database may also be a set of information on photomasks that are allowed to enter the machine, or a combination of the above two types of photomask information. The database selection can be determined according to actual usage needs, and this disclosure does not impose any specific limitations.

[0107] In step S102, the photomask detection method further includes: if the barcode reading device fails to read the barcode on the photomask, a calibration device is activated to calibrate the barcode reading device, and the calibrated barcode reading device rereads the barcode on the photomask.

[0108] Among them, such as Figure 10 As shown, calibrating the barcode reader includes:

[0109] S1021: Turn on the power supply to energize the electromagnet;

[0110] S1022: After being energized, the electromagnet pushes the calibration base to control the movement of the calibration rod, so that the top of the calibration rod presses the calibration button on the barcode reader to calibrate the barcode reader;

[0111] S1023: After maintaining the calibration for the predetermined time, disconnect the power supply to de-energize the electromagnet, and the calibration rod will reset under the action of the spring.

[0112] The calibration method for the calibration device is as follows: turn on the power supply to energize the electromagnet; after being energized, the electromagnet pushes the calibration base to control the movement of the calibration rod, so that the top of the calibration rod presses the calibration button on the barcode reader to calibrate the barcode reader; after maintaining the calibration for a predetermined time, turn off the power supply to de-energize the electromagnet, and the calibration rod resets under the action of the spring.

[0113] In this embodiment, the electromagnet is disposed at the bottom of the calibration rod, and the electromagnet and the calibration rod have the same polarity. Due to the principle of like poles repelling each other, the electromagnet can push the bottom of the calibration rod forward, pressing the calibration button to calibrate the barcode reader. Alternatively, the calibration device can be modified so that the electromagnet is disposed at the top of the calibration rod, with the electromagnet and the top of the calibration rod having different polarities. Due to the principle of opposite poles attracting each other, the energized electromagnet can attract the calibration rod forward, pressing the calibration button to calibrate the barcode reader. This disclosure includes, but is not limited to, the above-described calibration device and its modified forms.

[0114] In step S102, the photomask detection method further includes:

[0115] If the barcode reader fails to read the barcode on the photomask, the photomask thickness measuring device is activated to measure the thickness of the photomask.

[0116] Among them, such as Figure 11 As shown, the photomask thickness measuring device detects the thickness of the photomask by including:

[0117] S1031: The sensor module measures the distance between the sensor module and the robotic arm to obtain a first distance;

[0118] S1032: The robotic arm moves the photomask so that the photomask passes through the irradiation area of ​​the photomask thickness measuring device, and the sensor module measures the distance between the sensor module and the top surface of the photomask to obtain a second distance;

[0119] S1033: The difference between the first distance and the second distance is calculated, and the difference is the thickness of the photomask.

[0120] The method for measuring the thickness of a photomask using a photomask thickness measuring device is as follows: the sensor module measures the distance between the sensor module and the robotic arm to obtain a first distance S1; the robotic arm moves the photomask so that it passes through the illumination area of ​​the photomask thickness measuring device, and the sensor module measures the distance between the sensor module and the top surface of the photomask to obtain a second distance S2; the difference between the first distance S1 and the second distance S2 is calculated, and the difference is the thickness of the photomask, where the photomask thickness H = S2 - S1.

[0121] The photomask inspection method utilizes the photomask thickness measuring device, barcode reading device, and calibration device within the barcode reading device provided in this disclosure. The photomask information and the status information of the barcode reading device are transmitted to the control system via a signal processing circuit. Through command transmission from the control system, the photomask inspection system can perform the aforementioned operational steps. The signal processing circuit and control system provided in this disclosure can be of any form, capable of implementing the method of this disclosure, transmitting signals or commands, or controlling circuits. This disclosure does not specifically limit the type and connection method of the circuit and system, as long as it meets the usage requirements of this disclosure.

[0122] The photomask detection method disclosed herein, on the one hand, will activate the photomask thickness measuring device when the photomask barcode reading is abnormal, to measure the thickness of the photomask, and determine whether the photomask has the right to enter the machine by comparing the thickness of the photomask with the photomask information in the preset database.

[0123] On the other hand, when the barcode reading of the photomask is abnormal, the system will activate the calibration device to calibrate the barcode reading device and automatically verify the calibration results until the calibration is successful and then stop the calibration. The calibration speed of the barcode reading device is fast and the calibration result is accurate.

[0124] Thirdly, when a new photomask enters the machine, the photomask thickness measuring device is activated to compare the thickness of the new photomask with the machine's maximum allowable photomask thickness. If the thickness of the new photomask is greater than or equal to the maximum allowable thickness, the new photomask is prohibited from entering the machine, and the information of the new photomask is updated to the preset database. At the same time, access restrictions are set. If the thickness of the new photomask is less than the maximum allowable thickness, the new photomask is allowed to enter the machine. This method can further determine the access rights of the photomask to prevent photomasks that exceed the access rights from entering the machine and causing damage to the machine or the photomask, thereby improving the security of the barcode reading device and the photomask.

[0125] It should be noted that although the steps of the photomask detection method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that these steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0126] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the appended claims.

Claims

1. A method for detecting photomasks, characterized in that, include: A photomask thickness measuring device is provided, the photomask thickness measuring device includes multiple sensor modules arranged side by side, the sensor modules are used to measure the thickness of the photomask, and the total scanning length of the multiple sensor modules arranged side by side is greater than or equal to the width of the photomask; A barcode reading device is provided, which reads the barcode on the photomask and calls a pre-set database to determine whether the barcode is included in the database; A calibration device is provided, the calibration device including a calibration rod and an electromagnet, the calibration rod including a calibration lever and a calibration base, the electromagnet being disposed correspondingly to the bottom of the calibration base, and the calibration device being used to automatically calibrate the barcode reader when the barcode reader malfunctions; The determination of whether the barcode is included in the database includes: if the database does not contain the barcode of the photomask, then the photomask thickness measuring device is activated to measure the thickness of the photomask and obtain the maximum thickness value of the photomask; if the maximum thickness value of the photomask is less than a preset threshold, then the photomask is allowed to enter the machine; if the maximum thickness value of the photomask is greater than or equal to the preset threshold, then the photomask is prohibited from entering the machine, and permission information is set for the photomask, updating the barcode information of the photomask and the permission information to the database; If the barcode reading device fails to read the barcode on the photomask, the calibration device and the photomask thickness measuring device are activated; wherein the photomask thickness measuring device measures the thickness of the photomask, the calibration device calibrates the barcode reading device, and the calibrated barcode reading device rereads the barcode on the photomask.

2. The photomask detection method according to claim 1, characterized in that, The calibration of the barcode reader includes: Turn on the power supply to energize the electromagnet; When energized, the electromagnet pushes the calibration base to control the movement of the calibration rod, causing the tip of the calibration rod to press the calibration button on the barcode reader to calibrate the barcode reader; After maintaining the calibration for the predetermined time, disconnect the power supply to de-energize the electromagnet, and the calibration rod will reset under the action of the spring.

3. The photomask detection method according to claim 1, characterized in that, Measuring the thickness of the photomask using the sensor module includes: The sensor module measures the distance between the sensor module and the robotic arm to obtain a first distance; The robotic arm moves the photomask so that it passes through the illumination area of ​​the photomask thickness measuring device. The sensor module measures the distance between the sensor module and the top surface of the photomask to obtain a second distance. The difference between the first distance and the second distance is calculated, and the difference is the thickness of the photomask.

4. A photomask inspection system for implementing the photomask inspection method according to any one of claims 1-3, characterized in that, include: A photomask thickness measuring device includes multiple sensor modules arranged side by side, the sensor modules being used to measure the thickness of the photomask, wherein the total scanning length of the multiple sensor modules arranged side by side is greater than or equal to the width of the photomask; A barcode reading device is provided, which is positioned opposite the photomask thickness measuring device. The barcode reading device is used to read the barcode on the photomask to obtain the thickness information of the photomask. A calibration device is provided, comprising a calibration rod and an electromagnet. The calibration rod includes a calibration arm and a calibration base. The electromagnet is disposed correspondingly to the bottom of the calibration base. The calibration device is used to automatically calibrate the barcode reader when the barcode reader malfunctions.

5. The photomask inspection system according to claim 4, characterized in that, The calibration rod is connected to the top surface of the calibration base.

6. The photomask inspection system according to claim 4, characterized in that, The barcode reader also includes a calibration button, and the calibration lever calibrates the barcode reader by contacting the calibration button.

7. The photomask inspection system according to claim 4, characterized in that, The photomask detection system also includes a power supply, which uses a voltage regulator chip to provide voltage to the electromagnet, so that the electromagnet generates polarity after being energized.

8. The photomask inspection system according to claim 6, characterized in that, The diameter of the calibration rod is less than or equal to the diameter of the calibration button.

9. The photomask inspection system according to claim 4, characterized in that, Both the calibration base and the electromagnet are circular in shape, and the diameter of the calibration base is equal to the diameter of the electromagnet.

10. The photomask inspection system according to claim 4, characterized in that, The polarity of the calibration base is the same as the polarity of the electromagnet after it is energized.

11. The photomask inspection system according to claim 4, characterized in that, The calibration base is connected to the electromagnet in a non-contact manner.

12. The photomask inspection system according to claim 4, characterized in that, The calibration device also includes a spring that passes through the calibration rod.

13. The photomask inspection system according to claim 12, characterized in that, The length of the spring is equal to the length of the calibration rod.

14. The photomask inspection system according to claim 4, characterized in that, The calibration device also includes a fixed baffle with a through hole, through which the calibration rod passes.

15. The photomask inspection system according to claim 14, characterized in that, The fixed baffle is located at the top of the calibration rod.

16. The photomask inspection system according to claim 4, characterized in that, The sensor module includes a reflective photoelectric sensor.

Images