Sensing device for wafer manufacturing

Abstract

The utility model discloses a sensing device for wafer manufacturing, which comprises a reflection sensor, a transmitting end and a receiving end of the reflection sensor are arranged on the same side, a reflective mirror is arranged on the opposite side of the transmitting end and the receiving end, and the reflection sensor and the reflective mirror are arranged on one side, close to a wafer clamping plug, of the edge of a carrying table. When the wafer does not protrude, the light of the transmitting end is reflected to the receiving end through the reflector; when the wafer protrudes, the light is reflected to the receiving end through the protruding wafer, the receiving end judges whether the wafer protrudes or not according to different simulation light signals, and transparent and non-transparent wafers can be recognized. The device further comprises a signal processing module and the like. According to the utility model, the problem that the conventional light sensor cannot identify the projection of the transparent wafer is solved, whether the transparent and opaque wafers are projected can be identified, and the light sensor has the advantages of strong compatibility, high detection precision, simple structure, improved production safety and efficiency and the like.

Description

Technical Field

[0001] This utility model relates to the field of wafer manufacturing technology, and in particular to a sensing device for wafer manufacturing. Background Technology

[0002] In today's wafer manufacturing processes, plasma resist stripping equipment plays a crucial role. With continuously increasing manufacturing process requirements and a growing diversity of product types, the performance and stability of plasma resist stripping equipment have become a focus of industry attention. In the production process of automated plasma resist stripping equipment, cassettes are used to store wafers. The wafers are placed on a stage, and wafer scanning determines the number and position of wafers in the cassettes. Subsequently, a robotic arm completes the wafer handling, thereby realizing the relevant processes.

[0003] However, in actual operation, vibration is unavoidable when manually placing the cassette. This vibration may cause the wafer to shift, resulting in wafer bulging. Once the wafer bulges, it is very likely to collide with the scanning equipment during wafer scanning, causing the wafer to break. This not only leads to product scrap and increases production costs, but may also affect the entire production schedule.

[0004] To solve this problem, through-beam sensors are commonly used for sensing and judgment. For example... Figure 5 , Figure 6 As shown, the through-beam sensor consists of a transmitter A and a receiver B. During operation, the transmitter continuously emits light, while the receiver B receives the light emitted by the transmitter A. When an object blocks the path between the transmitter A and the receiver B, the light cannot reach the receiver B smoothly, and the light signal received by the receiver B will change. Based on this, the through-beam sensor can determine the presence of the object, thereby determining whether the wafer is protruding.

[0005] However, through-beam sensors have significant limitations, especially when dealing with transparent wafers. From an optical principle perspective, such as... Figure 7 As shown, a transparent wafer has high light transmittance. When the through-beam light emitted from transmitter A strikes the transparent wafer C, most of the light passes directly through the wafer and continues to propagate, with only a very small portion being reflected by the surface of wafer C. This results in extremely small, almost negligible, changes in the intensity, frequency, and other characteristics of the light signal received by receiver B compared to when there is no wafer obstruction. The signal processing mechanism of through-beam sensors typically identifies objects based on significant changes in the light signal. Therefore, receiver B cannot detect effective changes due to the obstruction of the transparent wafer C, and thus cannot accurately sense whether the transparent wafer is protruding. Therefore, developing a sensing device capable of effectively detecting whether transparent and opaque wafers are protruding is urgently needed. Utility Model Content

[0006] The present invention addresses the aforementioned shortcomings by providing a sensing device for wafer manufacturing. This device solves the problem that existing photosensitive sensors cannot identify transparent wafers when detecting whether a wafer is protruding, thus avoiding mechanical collisions during wafer scanning in production due to wafer protrusion and improving the safety and production efficiency of wafer manufacturing.

[0007] The above-mentioned objective of this utility model is achieved through the following technical solution: A sensing device for wafer manufacturing includes a reflective sensor, with the transmitting end and receiving end of the reflective sensor disposed on the same side, and a reflector disposed on the opposite side of the transmitting end and the receiving end. The reflective sensor and the reflector are mounted on the edge of the stage near the wafer chuck. When the wafer protrudes due to chuck jitter or other reasons, the light emitted from the transmitting end is more easily reflected by the protruding wafer to the receiving end. This unique structural design enables effective detection regardless of whether the wafer is transparent or opaque. When the wafer is not protruding, the light emitted from the transmitting end travels in a straight line, is reflected by the reflector on the opposite side, and reaches the receiving end smoothly; however, when the wafer protrudes, the light emitted from the transmitting end will first come into contact with the protruding wafer during propagation, and is then reflected by the protruding wafer to the receiving end. Since the propagation path of light is different under different conditions, the analog light signal received by the receiving end also differs. Based on this difference, it is possible to determine whether the wafer is protruding.

[0008] Sensor Type: The reflective sensor can be selected from one of the following: an infrared reflective sensor, a laser reflective sensor, or a visible light reflective sensor. Infrared reflective sensors utilize the reflective properties of infrared light and have good resistance to ambient light interference; laser reflective sensors feature high directionality and high energy density, resulting in high detection accuracy; visible light reflective sensors are easy to observe and adjust. Different types of reflective sensors can be selected based on the actual production environment and detection accuracy requirements.

[0009] Integrated Design: The transmitter and receiver are integrated into a single structure, which is positioned opposite the reflector. This integrated design not only simplifies the structure of the sensing device, facilitating installation and maintenance, but also ensures that the relative positions of the transmitter and receiver are fixed, improving the accuracy and stability of the detection.

[0010] Signal Processing Module: The sensing device also includes a signal processing module, which is connected to the receiving end. The signal processing module analyzes and processes the received analog light signal, outputting a judgment result regarding whether the wafer is protruding. Specifically, the signal processing module includes a signal amplifier, an analog-to-digital converter, and a microprocessor. The analog light signal output from the receiving end is first amplified by the signal amplifier to enhance signal strength and reduce signal loss and interference during transmission. Then, the amplified analog signal is converted into a digital signal by the analog-to-digital converter, facilitating digital computation and analysis by the microprocessor. Finally, the microprocessor analyzes and judges the digital signal according to a preset algorithm and threshold to determine whether the wafer is protruding and outputs the corresponding result.

[0011] Reflector Design: The reflector can be a plane mirror or a curved mirror, with its reflective surface polished to improve light reflection efficiency. Plane mirrors are suitable for scenarios with strict requirements on the direction of light reflection, accurately reflecting light to the receiving end. Curved mirrors, on the other hand, can converge or diverge light according to actual needs, expanding the detection range or improving detection accuracy. The polished reflective surface reduces light scattering and absorption, increasing light reflectivity and thus enhancing the detection performance of the sensing device.

[0012] The working principle of this invention is as follows: When the sensing device is working, the transmitting end continuously emits light. In the normal state where the wafer is not protruding, the light emitted by the transmitting end propagates directly to the reflector on the opposite side, and the reflector reflects the light back to the receiving end at a specific angle. At this time, the analog light signal received by the receiving end has specific characteristics such as intensity, frequency, and phase. These characteristics are amplified by the signal amplifier in the signal processing module, converted into a digital signal by the analog-to-digital converter, and transmitted to the microprocessor. The microprocessor determines that the wafer is in a non-protruding state based on a preset normal signal range.

[0013] When a wafer bulges out for various reasons, the light emitted from the transmitter first encounters the bulging wafer during its propagation. Due to the wafer's surface reflectivity, the light is reflected by the bulging wafer, changing its propagation direction, and eventually reaches the receiver. At this point, the analog light signal received by the receiver exhibits significant changes in intensity, frequency, and phase compared to when the wafer is not bulging. For example, after being reflected by the wafer, the light intensity may weaken, the frequency may slightly shift due to the reflective medium, and the phase may also change. These altered analog light signals are amplified by a signal amplifier, converted by an analog-to-digital converter, and then transmitted to the microprocessor. The microprocessor compares these signals with preset bulge signal characteristics to determine that the wafer is in a bulging state and outputs a corresponding warning signal to alert the operator, thereby effectively preventing mechanical collisions during wafer scanning.

[0014] The advantages of this utility model compared with the prior art are:

[0015] 1. Strong compatibility: It can identify whether transparent and opaque wafers are protruding, overcoming the limitations of traditional through-beam sensors. It is suitable for various types of wafer manufacturing processes, improving the versatility and applicability of sensing devices.

[0016] 2. High detection accuracy: By receiving light reflection signals under different conditions through a reflection sensor and performing precise analysis using a signal processing module, it can accurately determine whether the wafer is protruding, effectively reducing false positives and false negatives and improving detection accuracy.

[0017] 3. Simple structure: The transmitter and receiver are integrated into one unit and are positioned opposite the reflector. The overall structure is simple and clear, which facilitates installation, debugging and maintenance, and reduces the maintenance cost and failure rate of the equipment.

[0018] 4. Improve production safety and efficiency: Timely detection of wafer protrusion avoids mechanical collisions caused by wafer protrusion, reduces the risk of wafer breakage, improves the safety and efficiency of wafer manufacturing, and reduces production costs. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the working state when the wafer is bumped in Embodiment 1 of this utility model.

[0020] Figure 2 This is a schematic diagram of the working state when the wafer is not protruding in Embodiment 1 of this utility model.

[0021] Figure 3 This is a schematic diagram of the working state when the wafer is protruding in Embodiment 2 of this utility model.

[0022] Figure 4 This is a schematic diagram of the working state when the wafer is not protruding in Embodiment 2 of this utility model.

[0023] Figure 5 This is a schematic diagram of the working state of an existing through-beam sensor when it protrudes from a non-transparent wafer.

[0024] Figure 6 This is a schematic diagram of the working state of an existing through-beam sensor when the non-transparent wafer is not protruding.

[0025] Figure 7 This is a schematic diagram of the working state of an existing through-beam sensor when the transparent wafer is not protruding. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings.

[0027] Example 1:

[0028] like Figure 1 , Figure 2 As shown, in this embodiment, a sensing device for wafer manufacturing mainly consists of an infrared reflection sensor, a plane mirror 3, and a signal processing module. The infrared reflection sensor integrates the transmitter 1 and the receiver 2 into a small, integrated structure, which has the functions of emitting infrared light and receiving reflected infrared light. The reflective surface of the plane mirror 3 is highly polished, achieving a reflectivity of over 95%, and is used to reflect the infrared light emitted by the transmitter 1 to the receiver 2 under normal conditions. The signal processing module includes a signal amplifier, an analog-to-digital converter, and a microprocessor. The signal amplifier uses a low-noise, high-gain operational amplifier to enhance the weak analog light signal output by the receiver 2; the analog-to-digital converter uses a 12-bit resolution chip to accurately convert the amplified analog signal into a digital signal; the microprocessor uses a high-performance microcontroller with pre-stored analysis algorithms and judgment thresholds for the infrared reflection sensor signal, used to analyze and process the digital signal and determine whether the wafer 4 is protruding.

[0029] In practical applications, this module is installed on one side of the wafer stage, with a plane reflector 3 installed on the opposite side. When wafer 4 is not protruding, the infrared light emitted by transmitter 1 is reflected by plane reflector 3 and received by receiver 2. The analog light signal output by receiver 2 is amplified by a signal amplifier, converted by an analog-to-digital converter, and then transmitted to the microprocessor. The microprocessor determines that the signal is within the normal range and confirms that wafer 4 is not protruding. When wafer 4 protrudes, the infrared light is reflected by the protruding wafer 4 to receiver 2, and the analog light signal output by receiver 2 changes significantly. The microprocessor determines that wafer 4 is protruding based on the changed signal and issues a warning signal through an external warning light. Actual testing shows that this sensing device can accurately detect whether wafer 4 is protruding, with a detection accuracy of ±0.1mm.

[0030] Example 2:

[0031] like Figure 3 , Figure 4As shown, this embodiment of a sensing device for wafer manufacturing comprises a laser reflection sensor, a parabolic reflector 3, and a more powerful signal processing module. The laser reflection sensor integrates the transmitter 1 and receiver 2 into a single structure, capable of emitting laser light with high directionality and high energy density, and receiving the reflected laser signal. The parabolic reflector 3 is a type of curved reflector; its special parabolic shape allows it to focus and reflect the laser light emitted from the transmitter 1 to the receiver 2, thereby expanding the detection range. The signal processing module uses a high-speed, wideband amplifier for rapid response to changes in the laser reflection signal; a 16-bit resolution analog-to-digital converter improves signal conversion accuracy; and an industrial-grade microcontroller provides powerful computing capabilities and stability, enabling more efficient and accurate signal processing.

[0032] In practical applications, the integrated structure of transmitter 1 and receiver 2 is mounted above the wafer stage, with a parabolic reflector 3 mounted on the opposite side. When wafer 4 is not protruding, the laser emitted by transmitter 1 is converged and reflected by the parabolic reflector 3 and received by receiver 2. The signal processing module analyzes and determines that wafer 4 is not protruding. When wafer 4 protrudes, the laser is reflected by the protruding wafer 4, and receiver 2 receives analog light signals with different characteristics. The signal processing module accurately determines that wafer 4 is protruding and transmits the detection result to the host computer via the communication interface, facilitating automated control of the production process. Testing has shown that this sensing device can stably and accurately detect whether wafer 4 is protruding within a large detection range, meeting the needs of large-scale wafer 4 manufacturing.

[0033] As can be seen from the above embodiments, the sensing device of this utility model can effectively solve the problems existing in the prior art and has good market application prospects.

[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A sensing device for wafer manufacturing, characterized in that: The device includes a reflection sensor, with its transmitter and receiver positioned on the same side and a reflector on the opposite side. The reflection sensor and reflector are mounted on the edge of the stage near the wafer chuck. When the wafer is not protruding, the light emitted by the transmitter is reflected by the reflector to the receiver. When the wafer protrudes, the light emitted by the transmitter is reflected by the protruding wafer to the receiver. The receiver determines whether the wafer is protruding based on the different analog light signals received. This sensing device can identify transparent and opaque wafers.

2. The sensing device for wafer manufacturing according to claim 1, characterized in that: The reflection sensor is one of an infrared reflection sensor, a laser reflection sensor, or a visible light reflection sensor.

3. The sensing device for wafer manufacturing according to claim 1, characterized in that: The transmitter and receiver are integrated into a single structure, and this integrated structure is positioned opposite to the reflector.

4. The sensing device for wafer manufacturing according to claim 1, characterized in that: The sensing device also includes a signal processing module. The receiving end is connected to the signal processing module, which is used to analyze and process the received analog light signal and output a judgment result on whether the wafer is protruding.

5. A sensing device for wafer manufacturing according to claim 4, characterized in that: The signal processing module includes a signal amplifier, an analog-to-digital converter, and a microprocessor. The analog light signal output from the receiving end is amplified by the signal amplifier, converted into a digital signal by the analog-to-digital converter, and then transmitted to the microprocessor for analysis and judgment.

6. A sensing device for wafer manufacturing according to claim 1, characterized in that: The reflector is a flat reflector or a curved reflector, and its reflective surface is polished to improve light reflection efficiency.

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