Method for detecting fores in a processing tank
By setting identification patterns on the bottom of the processing tank or on the optical lens, and using image comparison technology, the problem of misjudgment in foreign object detection in semiconductor manufacturing processes has been solved, achieving high accuracy and timely intervention, and reducing losses.
Patent Information
- Application Number
- CN202410642743.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-05-10
- Filing Date
- 2024-05-23
- Publication Date
- 2025-11-11
AI Technical Summary
In existing semiconductor manufacturing processes, the accuracy of foreign object detection in the processing tank is affected by factors such as the liquid in the processing tank, the reflection of foreign objects, and the angle, leading to misjudgments.
The method involves setting identification patterns at the bottom of the processing tank or on the optical lens. By comparing the images of the wafer before and after entering the processing tank, the presence of foreign objects can be determined by the image differences, thus avoiding interference from liquid and foreign object reflections.
It improves the accuracy of foreign object detection, enabling timely detection and handling of foreign objects, and reducing losses caused by foreign object residue.
Smart Images
Figure CN120928463A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for detecting foreign objects in a processing tank during semiconductor manufacturing processes, and particularly to a method for detecting foreign objects in a processing tank. Background Technology
[0002] In semiconductor manufacturing processes, continuous monitoring of the wafer's condition within the processing tank is crucial. This not only ensures product quality but also allows for immediate intervention to mitigate potential losses. Typically, the monitoring device / system is mounted on a robotic arm, as the wafer moves with the arm and is protected from highly corrosive liquids within the tank. However, this can compromise the accuracy of the inspection. For instance, when identifying foreign objects in the processing tank, optical lenses are often used to measure the ratio of bright to dark areas to determine the presence of foreign objects. However, this method is susceptible to misjudgments due to factors such as the liquid level in the tank, the reflection of the foreign object, and the angle of the object. Summary of the Invention
[0003] The present invention provides a method for detecting foreign objects in a processing tank. The method uses an identification pattern on the bottom of the processing tank or on an optical lens to avoid misjudgment caused by interference from factors such as the liquid in the processing tank, the reflection of the foreign object, and the angle of the foreign object in identifying whether there is a foreign object in the processing tank.
[0004] An embodiment of the present invention provides a method for detecting foreign objects in a processing tank, comprising: capturing an identification pattern disposed on the bottom of the processing tank or disposed on the optical lens using an optical lens to obtain a first image; placing a wafer in the processing tank; removing the wafer from the processing tank; capturing an image of the processing tank after the wafer has been removed using the optical lens to obtain a second image; and identifying the second image and the first image. If the second image is the same as the first image, the identification is considered successful and a first signal is output; if the second image is different from the first image, the identification is considered unsuccessful and a second signal is output.
[0005] In some embodiments, the first signal enables the process equipment to maintain the process program and continue placing the next wafer in the processing tank, while the second signal enables the process equipment to issue a warning or stop the process program.
[0006] In some embodiments, the identification pattern includes a grid pattern.
[0007] In some embodiments, the foreign object includes a wafer fragment.
[0008] In some embodiments, the method for detecting foreign objects in a processing tank further includes: illuminating the processing tank by turning on a light source configured around the processing tank before taking a picture of the processing tank after the wafer has been removed from the processing tank using an optical lens.
[0009] In some embodiments, the method for detecting foreign objects in a processing tank further includes: after identifying a foreign object as qualified and outputting a first signal, the first signal can turn off the light source.
[0010] In some embodiments, the light source is positioned below the processing tank.
[0011] In some embodiments, the wafer is removed from the processing tank by a robotic arm, with a light source disposed on the robotic arm.
[0012] In some embodiments, the optical lens is mounted on a robotic arm.
[0013] In some embodiments, the processing tank is filled with water that can completely immerse the wafer.
[0014] Based on the above, in the above method for detecting foreign objects in a processing tank, the identification pattern on the bottom of the processing tank or on the optical lens is used to avoid misjudgment caused by interference from liquid in the processing tank, reflection of foreign objects, angle of foreign objects, etc., in identifying whether foreign objects exist in the processing tank. Attached Figure Description
[0015] Figure 1A and Figure 1B This is a top view and a cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to an embodiment of the present invention.
[0016] Figure 1C This is a flowchart of a method for detecting foreign objects in a processing tank according to an embodiment of the present invention.
[0017] Figure 2A This is a top view and cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention.
[0018] Figure 2B This is a flowchart of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention.
[0019] Figure 3 This is a cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention.
[0020] Figure 4 This is a cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention.
[0021] [Symbol Explanation]
[0022] 10, 20: Optical lenses
[0023] 12: Light source
[0024] 100: Processing tank
[0025] 110, 210: Pattern Identification
[0026] 1000: Foreign object
[0027] R1, R2: Areas
[0028] S1, S2, S3, S31, S32, S4, S5, S6: Steps Detailed Implementation
[0029] The invention is described more fully with reference to the accompanying drawings of this embodiment. However, the invention may be embodied in various different forms and should not be limited to the embodiments described herein. The thicknesses of layers and regions in the drawings are enlarged for clarity. The same or similar reference numerals denote the same or similar elements, which will not be repeated in the following paragraphs.
[0030] It should be understood that when an element is referred to as being "on" or "connected" to another element, it may be directly on or connected to the other element, or there may be intermediate elements present. If an element is referred to as being "directly on" or "directly connected" to another element, there are no intermediate elements present. As used herein, "connection" may refer to a physical and / or electrical connection, while "electrical connection" or "coupling" may refer to the presence of other elements between two elements. "Electrical connection" as used herein may include physical connections (e.g., wired connections) and physical disconnections (e.g., wireless connections).
[0031] As used herein, “about,” “approximately,” or “substantially” includes the value mentioned and the average value within an acceptable range of deviations from a particular value that can be determined by a person skilled in the art, taking into account the measurement under discussion and a particular number of errors associated with the measurement (i.e., limitations of the measurement system). For example, “about” may mean within one or more standard deviations of the value, or within ±30%, ±20%, ±10%, ±5%. Furthermore, the use of “about,” “approximately,” or “substantially” herein may be chosen based on the optical, etched, or other properties to select a more acceptable range of deviations or standard deviations, and may not require a single standard deviation to apply to all properties.
[0032] The terminology used herein is for illustrative purposes only and is not intended to limit the scope of this disclosure. In this context, the singular form includes the plural form unless the context otherwise requires.
[0033] Figure 1A and Figure 1BThis is a top view and a cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to an embodiment of the present invention. Figure 1C This is a flowchart of a method for detecting foreign objects in a processing tank according to an embodiment of the present invention. Figure 2A This is a top view and cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention. Figure 2B This is a flowchart of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention. Figure 3 This is a cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention. Figure 4 This is a cross-sectional schematic diagram of a method for detecting foreign objects in a processing tank according to another embodiment of the present invention.
[0034] Please refer to Figure 1A , Figure 1B and Figure 1C A method for detecting foreign objects in a processing tank may include the following steps.
[0035] First, proceed as follows Figure 1C The illustrated step S1 (i.e., recording the bottom pattern) involves capturing a first image of the identification pattern 110 disposed at the bottom of the processing tank 100 using an optical lens 10. In some embodiments, the identification pattern 110 may include a grid pattern.
[0036] Next, proceed as follows Figure 1C Step S2 (i.e., wafer entering the water tank) is shown. A wafer (not shown) is placed in a processing tank 100. In some embodiments, the processing tank 100 is filled with water sufficient to completely immerse the wafer. In this embodiment, the processing tank 100 may be a water tank.
[0037] Then, proceed as follows Figure 1C The step S3 shown is (i.e., picking up the wafer with an arm at a specific location). The wafer is removed from the processing tank 100 and placed at a specific location.
[0038] Then, proceed as follows Figure 1C The step S4 shown is "taking and transmitting a photo". The processing tank 100 after the wafer is taken out of the processing tank 100 is photographed by the optical lens 10 to obtain a second image.
[0039] After that, proceed as follows Figure 1C The illustrated step S5 (i.e., identification) involves identifying the second image against the first image. If the second image is identical to the first image, the identification is considered successful (e.g., ...). Figure 1C The output signal is the first signal (as shown in the image). If the second image is different from the first image, the identification is considered a failure (e.g., ...). Figure 1CThe identification pattern 110 clearly identifies the foreign object 1000, avoiding misjudgments caused by interference such as liquid in the processing tank 100, reflections from the foreign object, and the angle of the foreign object. For example, even if a sheet-like foreign object 1000 (e.g., a wafer fragment) falls into the processing tank 100 at an angle, the present invention will not misjudge due to the reflection of the foreign object 1000. This is because the above identification is based on the difference between the first image and the second image (e.g., the second image is the same as the first image in region R1, while the second image is different from the first image in region R2) rather than on the ratio of bright and dark areas in the processing tank 100. In other words, the present invention effectively avoids interference such as liquid in the processing tank 100, reflections from the foreign object 1000, and the angle of the foreign object 1000 by using the identification pattern 110 provided at the bottom of the processing tank 100.
[0040] In some embodiments, a first signal enables the process equipment to maintain the process and continue placing the next wafer into the processing tank 100, while a second signal enables the process equipment to issue a warning or stop the process (e.g., step S6). This allows for immediate intervention when a situation occurs (e.g., wafer fragments remain in the processing tank 100), reducing associated losses. For example, a subsequent wafer placed in the processing tank 100 may collide with a wafer fragment remaining in the processing tank 100, causing secondary damage. In some embodiments, the foreign object 1000 may include wafer fragments.
[0041] Please refer to Figure 2A and Figure 2B The method for detecting foreign objects in a processing tank may further include illuminating the processing tank 100 by turning on a light source 12 disposed around the processing tank 100 to illuminate the processing tank 100 before photographing the processing tank 100 after the wafer has been removed from the processing tank 100 through the optical lens 10 (e.g., by turning on the light source 12 disposed around the processing tank 100). Figure 2B As shown in step S31), this increases the clarity of the second image acquired in the subsequent step S4, thereby improving the accuracy of identifying the first and second images in step S5. Furthermore, as mentioned above, the reflection from the foreign object 1000 does not interfere with the identification process; therefore, the placement of the light source 12 can significantly improve the accuracy of the identification. In some embodiments, the light source 12 may be positioned below or above the processing tank 100. In some embodiments, the wafer is processed by a robotic arm (such as...) Figure 2B The robotic arm mentioned in step S3 is removed from the processing tank 100, and the light source 12 may be disposed on the robotic arm. In some embodiments, the optical lens 10 may also be disposed on the robotic arm. In this embodiment, the specific position where the wafer is removed from the processing tank 100 and moved is the position where the second image is captured.
[0042] In some embodiments, when identified as qualified (e.g.) Figure 2B After the first signal is output (as shown in the diagram), the first signal can turn off the light source 12 (e.g., the pass). Figure 2B The step S32 shown is used to maintain the process program of the manufacturing equipment and continue to place the next wafer in the processing tank 100.
[0043] Please refer to Figure 3 and Figure 4 The recognition pattern 210 can be set on the optical lens 20. In this way, when performing tasks such as... Figure 1C In step S1 (i.e., recording the bottom image), the identification pattern 210 set on the optical lens 20 can also be photographed by the optical lens 20 to obtain the first image.
[0044] In summary, in the method for detecting foreign objects in a processing tank according to the above embodiments, the identification pattern on the bottom of the processing tank or on the optical lens is used to avoid misjudgment caused by interference from liquid in the processing tank, reflection of foreign objects, angle of foreign objects, etc., in identifying whether foreign objects exist in the processing tank.
Claims
1. A method for detecting foreign objects in a processing tank, comprising: A first image is obtained by photographing the identification pattern set at the bottom of the processing tank or on the optical lens using an optical lens; The wafer is placed in the processing tank; The wafer is removed from the processing tank; A second image is obtained by taking a picture of the processing tank after the wafer has been removed from the processing tank using the optical lens; as well as The second image is compared with the first image. If the second image is the same as the first image, it is considered qualified and a first signal is output. If the second image is different from the first image, it is considered unqualified and a second signal is output.
2. The method for detecting foreign objects in a processing tank as claimed in claim 1, wherein the first signal enables the process equipment to maintain the process program and continue placing the next wafer in the processing tank, and the second signal enables the process equipment to issue a warning or stop the process program.
3. The method for detecting foreign objects in a processing tank as claimed in claim 1, wherein the identification pattern includes a grid pattern.
4. The method for detecting foreign matter in a processing tank as claimed in claim 1, wherein the foreign matter includes a wafer fragment.
5. The method for detecting foreign objects in a processing tank as described in claim 1, further comprising: Before photographing the processing tank after the wafer has been removed from the processing tank through the optical lens, a light source disposed around the processing tank is turned on to illuminate the processing tank.
6. The method for detecting foreign objects in a processing tank as described in claim 5, further comprising: After being identified as qualified and the first signal is output, the first signal can turn off the light source.
7. The method for detecting foreign objects in a processing tank as described in claim 5, wherein the light source is disposed below the processing tank.
8. The method for detecting foreign objects in a processing tank as claimed in claim 5, wherein the wafer is removed from the processing tank by a robotic arm, and the light source is disposed on the robotic arm.
9. The method for detecting foreign objects in a processing tank as claimed in claim 8, wherein the optical lens is disposed on the robotic arm.
10. The method for detecting foreign matter in a processing tank as claimed in claim 1, wherein the processing tank is filled with water capable of completely immersing the wafer therein.