Wafer gap detection device

Abstract

The invention relates to the technical field of wafer gap detection, in particular to a wafer gap detection device which comprises a sensor and a wafer supporting piece. The sensor comprises a transmitting module and a receiving module, and the transmitting module is provided with a transmitting lamp; the receiving module is provided with a photosensitive device; the transmitting lamp and the photosensitive device are arranged at an interval, the transmitting module transmits light rays to the photosensitive device through the transmitting lamp, and the receiving module receives the transmitted light rays through the photosensitive device and outputs current or voltage with corresponding magnitude according to the illumination intensity of the received light rays; and the wafer supporting piece is used for supporting the wafer and can drive the wafer to rotate around the rotation axis of the wafer supporting piece, so that the edge of the wafer sequentially passes through the space between the emission lamp and the photosensitive device to partially shield the light of the emission lamp. According to the detection method, the wafer does not need to be photographed, and accessories such as a light source do not need to be additionally mounted, so that the space can be greatly saved, and the space occupancy rate of the detection device is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer notch detection, and in particular to a wafer notch detection device. Background Art

[0002] Against the backdrop of the rapid development of the domestic semiconductor industry, the wafer industry chain is growing stronger and stronger, and there are more and more types of equipment used to produce and process wafers. Many devices must first locate the direction of the wafer notch when producing and processing wafers. At present, domestic detection equipment for wafer positioning generally uses array cameras or linear cameras. Among them, the camera needs to install additional auxiliary tools such as light sources, and the space occupancy rate is large, so there is an urgent need to solve this situation. Summary of the invention

[0003] In view of this, the present invention provides a wafer notch detection device, the main technical problem to be solved is: how to reduce the space occupancy rate of the detection device.

[0004] In order to achieve the above object, the present invention mainly provides the following technical solutions: An embodiment of the present invention provides a wafer notch detection device, including a sensor and a wafer support; The sensor comprises a transmitting module and a receiving module, wherein the transmitting module has a transmitting lamp; the receiving module has a photosensitive device; the transmitting lamp and the photosensitive device are arranged at intervals, the transmitting module transmits light to the photosensitive device through the transmitting lamp, the receiving module receives the emitted light through the photosensitive device, and outputs a current or voltage of corresponding magnitude according to the light intensity of the received light; The wafer support is used to support the wafer and can drive the wafer to rotate around the rotation axis of the wafer support, so that the edge of the wafer passes between the emitting lamp and the photosensitive device in sequence to partially block the light of the emitting lamp.

[0005] In some embodiments, the number of the transmitting modules is more than two, and the number of the receiving modules is equal to the number of the transmitting modules and corresponds one to one; The wafer support is used to support wafers of different specifications, and when driving the wafer of corresponding specifications to rotate around the rotation axis, the edge of the wafer of this specification passes between the corresponding emitting lamp and the photosensitive device in sequence.

[0006] In some embodiments, the transmitting module further includes a control gate circuit, and the control gate circuit is used to control the on and off of the circuit where the transmitting light is located according to the signal; The control gate circuit of each transmitting module is connected to the controller, and each transmitting module corresponds to the wafer specification one by one; the controller is used to send a conduction signal to the control gate circuit of the corresponding transmitting module according to the specifications of the wafer placed on the wafer support, and send a disconnection signal to the control gate circuits of other transmitting modules.

[0007] In some embodiments, the wafer notch detection device further includes a support frame, a transmitting plate and a receiving plate; the transmitting plate and the receiving plate are both fixed on the support frame, and the transmitting plate and the receiving plate are spaced apart; the transmitting modules are both arranged on the transmitting plate, and the receiving modules are both arranged on the receiving plate.

[0008] In some embodiments, the transmitting module further includes a power supply module and a power supply voltage stabilizing circuit; The power supply module is used to supply power to the circuit where the transmitting light is located; The power supply voltage stabilizing circuit is used to stabilize the output voltage of the power supply module.

[0009] In some embodiments, the transmitting module further includes a first power amplifier circuit; and the power supply module is connected to the transmitting lamp via the first power amplifier circuit.

[0010] In some embodiments, the receiving module includes a second power amplifier circuit, and the second power amplifier circuit is connected to the output end of the photosensitive device to amplify the current or voltage output by the photosensitive device.

[0011] In some embodiments, the wafer support is provided with a vacuum suction port to suction the wafer through the vacuum suction port.

[0012] In some embodiments, the wafer notch detection device further includes a driving mechanism, and the driving mechanism is used to drive the wafer support to rotate around a rotation axis.

[0013] By means of the above technical solution, the wafer notch detection device of the present invention has at least the following beneficial effects: The wafer notch detection method of the present invention is different from the traditional camera visual detection. The camera visual detection needs to be mounted on the top of the wafer to take pictures, and a light source module needs to be installed, which requires a large installation space. The detection method of the present invention does not need to take pictures of the wafer, and does not need to install additional accessories such as light sources, thereby greatly saving space and reducing the space occupancy rate of the detection device.

[0014] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic diagram of a wafer notch detection device provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the edge of the wafer partially blocking the emitted light; Figure 3 is a schematic diagram of a transmitting circuit of a transmitting module provided by an embodiment of the present invention; Figure 4 It is a circuit diagram of a receiving module provided by an embodiment of the present invention.

[0016] Figure numerals: 1. wafer support; 2. driving mechanism; 3. sensor; 4. support frame; 31. transmitting plate; 32. receiving plate; 311. transmitting lamp; 321. photosensitive device; 100. wafer; 101. vacuum adsorption port. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0019] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0020] like Figure 1 As shown, an embodiment of the present invention provides a wafer notch detection device, which includes a sensor 3 and a wafer support 1. The sensor 3 includes a transmitting module and a receiving module, and the transmitting module has a transmitting lamp 311, which can be an infrared LED lamp, and preferably, the transmitting lamp 311 can emit a linear laser.

[0021] The aforementioned receiving module has a photosensitive device 321, which can be a silicon photocell. The transmitting lamp 311 and the photosensitive device 321 are arranged at intervals. The transmitting module transmits light to the photosensitive device 321 through the transmitting lamp 311. The receiving module receives the emitted light through the photosensitive device 321, and outputs a current or voltage of corresponding magnitude according to the light intensity of the received light. Among them, when the light intensity of the light received by the photosensitive device 321 is different, the current or voltage output by the receiving module will also be different.

[0022] The aforementioned wafer support 1 is used to support the wafer 100. The wafer support 1 has a rotation axis a, and the wafer support 1 can rotate around the rotation axis a. When the wafer support 1 drives the wafer 100 to rotate around the rotation axis a, the edge of the wafer 100 can pass between the emission lamp 311 and the photosensitive device 321 in sequence to partially block the light of the emission lamp 311.

[0023] In the above example, the edge of the wafer 100 has a notch, such as Figure 2 As shown, when the wafer 100 rotates, its edge passes between the emission lamp 311 and the photosensitive device 321 in sequence. The edge at the notch and the edge at other positions block different areas of the emission lamp 311, so that the area of ​​light received by the photosensitive device 321 is different, and thus the light intensity received by the photosensitive device 321 is different. The receiving module can output different currents or voltages according to different light intensities, so the position of the notch can be determined according to the difference in the current or voltage output by the receiving module.

[0024] The wafer notch detection method of the present invention is different from the traditional camera visual detection. The camera visual detection needs to be mounted on the top of the wafer 100 to take pictures, and a light source module needs to be installed, which requires a large installation space. The detection method of the present invention does not need to take pictures of the wafer 100, and does not need to install additional accessories such as light sources, thereby greatly saving space and reducing the space occupancy rate of the detection device.

[0025] In addition, when the wafer 100 is rotating, the sensor 3 can also collect the position of the edge of the wafer 100 in real time and fit the center position of the wafer 100 according to the range of the light received by the photosensitive device 321 from the transmitting lamp 311 blocked by the edge of the wafer 100. The circular position of the wafer 100 can then be compared with the preset position. When the two are inconsistent, the position of the wafer 100 can be corrected so that the center of the wafer 100 is located at the preset position.

[0026] Preferably, the number of the aforementioned transmitting modules is more than two, and the number of the aforementioned receiving modules is equal to the number of the transmitting modules and corresponds one to one. The aforementioned wafer support 1 is used to support wafers 100 of different specifications, for example, it can support 8-inch wafers or 12-inch wafers. When the wafer support 1 drives the wafer 100 of corresponding specifications to rotate around the rotation axis a, the edge of the wafer 100 of this specification passes between the corresponding transmitting lamp 311 and the photosensitive device 321 in sequence.

[0027] In the above example, each transmitting module and the corresponding receiving module form a detection module, the number of detection modules is more than two, and each detection module corresponds to a specification of wafer 100. When the rotating support supports a wafer 100 of a certain specification, the edge of the wafer 100 of the specification can just extend between the transmitting lamp 311 and the photosensitive device 321 of the corresponding detection module to be detected by the detection module.

[0028] In a specific application example, the number of both the aforementioned transmitting modules and receiving modules is two, one transmitting module and its corresponding receiving module form a first detection module, and the other transmitting module and its corresponding receiving module form a second detection module. Among them, the first detection module is used to detect 8-inch wafers, and the second detection module is used to detect 12-inch wafers. Specifically, when an 8-inch wafer is placed on the wafer support 1, the edge of the 8-inch wafer just extends between the transmitting light 311 and the photosensitive device 321 of the first detection module, so that the first detection module can detect its edge. When a 12-inch wafer is placed on the wafer support 1, the edge of the 12-inch wafer just extends between the transmitting light 311 and the photosensitive device 321 of the second detection module, so that the second detection module can detect its edge.

[0029] The aforementioned transmitting module may also include a control gate circuit, which is used to control the on and off of the circuit where the transmitting lamp 311 is located according to the signal. Among them, the control gate circuit of each transmitting module is connected to the controller, and each transmitting module corresponds to the wafer specification one by one. The controller is used to send a conduction signal to the control gate circuit of the corresponding transmitting module according to the specification of the wafer 100 placed on the wafer support 1, and send a disconnection signal to the control gate circuits of other transmitting modules. Specifically, when an 8-inch wafer is placed on the wafer support 1, the controller transmits a conduction signal to the control gate circuit of the transmitting module corresponding to the 8-inch wafer, so that the transmitting lamp 311 of the transmitting module emits light to detect the edge of the 8-inch wafer. At the same time, the controller also transmits a disconnection signal to the control gate circuits of other transmitting modules to turn off the transmitting lamps 311 of other transmitting modules, which can greatly extend the life of the transmitting lamp 311 and solve the problem of light intensity attenuation.

[0030] It should be noted here that: a wafer specification signal can be manually input into the controller, and the controller sends a conduction signal to the control gate circuit of the corresponding transmitting module according to the wafer specification signal, and sends a disconnection signal to the control gate circuits of other transmitting modules. Of course, an identification module can also be set to identify the specifications of the wafer 100, and the identification module generates a wafer specification signal according to the specifications of the wafer 100 on the wafer support 1. The controller sends a conduction signal to the control gate circuit of the corresponding transmitting module according to the wafer specification signal, and sends a disconnection signal to the control gate circuits of other transmitting modules.

[0031] like Figure 1 As shown, the aforementioned wafer notch detection device may further include a support frame 4, and the sensor includes a transmitting plate 31 and a receiving plate 32. The aforementioned transmitting plate 31 and the receiving plate 32 are both fixed on the support frame 4, and the transmitting plate 31 and the receiving plate 32 are arranged at intervals. The aforementioned transmitting modules are all arranged on the transmitting plate 31, and the aforementioned receiving modules are all arranged on the receiving plate 32.

[0032] In the above example, the sensor 3 can detect the gaps of wafers 100 of different specifications. The transmitting circuits of the above transmitting modules and the receiving circuits of the receiving modules can be integrated on the same circuit board, so that one circuit board integrates more than two detection channels. In a specific application example, a circuit board integrates two detection channels, and a more suitable transmitting lamp 311 is selected to transmit infrared bands for detection, eliminating other unused functions like displacement sensor 3, and the circuit is simpler, more reliable and more cost-effective. Among them, the wavelength of infrared light emitted by each transmitting lamp 311 can be 920nm.

[0033] The aforementioned transmitting module may also include a power supply module and a power supply voltage stabilizing circuit. The power supply module is used to supply power to the circuit where the transmitting lamp 311 is located. The power supply voltage stabilizing circuit is used to stabilize the output voltage of the power supply module.

[0034] The aforementioned transmitting module further includes a first power amplifier circuit, and the power supply module is connected to the transmitting lamp 311 via the first power amplifier circuit. The first power amplifier circuit can amplify the voltage to drive the high-power transmitting lamp 311 to emit laser.

[0035] Figure 3A schematic diagram of a transmitting circuit of a transmitting module is shown, which includes a thyristor V1, a light emitting diode H1, a resistor R1, a resistor R2, a resistor R3, a first capacitor C1, a first voltage connection terminal +v1, a second voltage connection terminal -v1 and a signal access terminal IN. The control electrode of the thyristor is connected to the first voltage connection terminal +v1, the first electrode of the thyristor is connected to one end of the second resistor R2, the second electrode of the thyristor is connected to one end of the third resistor R3, the other end of the third resistor is connected to one end of the light emitting diode H1, the other end of the light emitting diode H1 is connected to one end of the first capacitor C1, and the connection ends of the two are commonly connected to the second voltage connection terminal -v1; the other end of the first capacitor C1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to the other end of the second resistor R2, and the connection ends of the two are commonly connected to the signal access terminal IN.

[0036] In a specific application example, the first voltage connection terminal +v1 is used to connect a +5v voltage, the second voltage connection terminal -v1 is used to connect a -5v voltage, and the signal access terminal IN is used to connect to a controller.

[0037] The aforementioned receiving module may include a second power amplifier circuit, which is connected to the output end of the photosensitive device 321 to amplify the current or voltage output by the photosensitive device 321. In a specific application example, after the photosensitive device receives light, it will generate a weak voltage. The voltage output by the photosensitive device is amplified by a specified multiple through the second power amplifier circuit to output a voltage analog quantity; then the AD module can be used to collect the analog quantity, and the size of the analog quantity is the amount of light shielding.

[0038] Figure 4 A circuit diagram of a receiving module is shown, which includes a photosensitive device V2, an operational amplifier U, a fourth resistor R4, a sliding rheostat R5, a sixth resistor R6, a second capacitor C2, and an output terminal OUT. Among them, one end of the photosensitive device V2 is connected to one end of the sixth resistor R6, and both are connected to the reverse input terminal of the operational amplifier U, the other end of the photosensitive device V2 is connected to one end of the second capacitor C2, and both are connected to the same-direction input terminal of the operational amplifier U, the other end of the photosensitive device V2 is also connected to the other end of the second capacitor C2, and both are connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to one end of the sliding rheostat R5, the other end of the sliding rheostat R5 is connected to the output terminal of the operational amplifier U, and both are connected to the output terminal OUT, and the other end of the sixth resistor R6 is grounded.

[0039] like Figure 1As shown, the aforementioned wafer support 1 may be provided with a vacuum suction port 101 to suction the wafer 100 through the vacuum suction port 101. The wafer notch detection device may further include a driving mechanism 2, which is used to drive the wafer support 1 to rotate around the rotation axis a. The driving mechanism 2 may include a motor to drive the wafer support 1 to rotate through the motor.

[0040] The working principle and preferred embodiments of the present invention are introduced below.

[0041] The present invention is to design a wafer notch detection device, which is specifically used for wafer notch alignment, using the light-sensitive characteristics of a photosensitive device 321, such as a silicon photocell, and the different areas of light received by the silicon photocell when the wafer 100 rotates to judge the notch of the wafer 100. The sensor 3 structure is divided into an upper infrared receiving module and a lower infrared transmitting module. The basic structure is composed of an aluminum block substrate, a circuit board supporting copper columns, an internal circuit board, an outer cover, and a filter. The circuit structure of the sensor 3 is composed of a transmitting circuit, a receiving circuit, an amplifying circuit, and a filtering circuit. The basic principle is that according to the characteristics of the silicon photocell, the transmitting module transmits light of the corresponding wavelength to the silicon photocell, and the silicon photocell amplifies the voltage through the internal amplifier circuit and outputs it after filtering.

[0042] The present invention solves the following technical problems: 1. Greatly reduce the detection cost and the impact of restrictions on foreign high-end sensors; 2. The frequency of data collection is increased while reducing the space occupancy of the detection module; 3. Enhanced the anti-interference ability of the sensor.

[0043] The technical effect of the present invention is as follows: simple components are used to realize the intensity of the corresponding band of red line detection and feedback of the corresponding analog quantity, the circuit structure is simple and the response speed is fast, which reduces the cost and also reduces the installation volume of the sensor 3.

[0044] The sensor 3 of the present invention is used to detect the edge of the wafer 100. When the wafer 100 rotates, the sensor 3 collects the position of the edge of the wafer 100 in real time according to the range of infrared light received by the silicon photocell blocked by the edge of the wafer 100, and performs fitting to calculate the notch position and the center position of the wafer 100. This is different from the traditional camera visual detection. The camera visual detection needs to be mounted on the top of the wafer 100 to take pictures, and the light source module needs to be installed, which requires a large installation space. The camera field of view for detecting 8 inches and 12 inches is also different. If one camera is not compatible and two cameras are required, this also greatly increases the detection cost. At the same time, when using a standard displacement sensor, two sensors are also needed, which also takes up more space and the displacement sensor is more expensive. Although there are many functions, they are not used in the detection of the wafer 100. The sensor 3 of the present invention is compatible with the notch alignment of 8-inch wafers and 12-inch wafers 100 according to the different sizes of wafers 100. The infrared wavelengths of its two detection channels are both 920nm. A circuit board integrates two detection channels, and a more appropriate infrared band is selected for detection. Other unused functions of similar displacement sensors 3 are eliminated, and the circuit is simpler, more reliable and more cost-effective.

[0045] The entire sensor 3 is divided into a receiving module and a transmitting module. The main function of the receiving module is to receive infrared rays, generate current or voltage according to the light intensity of the received infrared rays, and then amplify the current or voltage and output it to the main control device. The host computer analyzes the received current or voltage data and determines the center of the wafer 100 and the position of the notch. The main function of the transmitting module is to provide infrared light of a specific wavelength for the silicon photocell. There are two transmitting modules. The infrared LED lights of the two transmitting modules will automatically trigger the detection of the wafer 100 of the corresponding size according to the selection settings on the host computer. The infrared LED lights do not need to be lit for a long time, which greatly extends the life of the LED lights and the problem of light intensity attenuation.

[0046] It should be noted here that: in the absence of conflict, technicians in this field can combine the relevant technical features in the above examples according to actual conditions to achieve corresponding technical effects, and the specific combinations are not described here one by one.

[0047] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A wafer (100) notch detection device, characterized in that: It comprises a sensor (3) and a wafer (100) support (1); The sensor (3) comprises a transmitting module and a receiving module, the transmitting module having a transmitting lamp (311); the receiving module having a photosensitive device (321); the transmitting lamp (311) and the photosensitive device (321) are arranged at intervals, the transmitting module transmits light to the photosensitive device (321) through the transmitting lamp (311), the receiving module receives the emitted light through the photosensitive device (321), and outputs a current or voltage of a corresponding magnitude according to the illumination intensity of the received light; The wafer (100) support (1) is used to support the wafer (100) and can drive the wafer (100) to rotate around the rotation axis of the wafer (100) support (1), so that the edge of the wafer (100) passes between the emitting lamp (311) and the photosensitive device (321) in sequence to partially block the light of the emitting lamp (311).

2. The wafer (100) notch detection device according to claim 1, characterized in that: The number of the transmitting modules is more than two, and the number of the receiving modules is equal to the number of the transmitting modules and corresponds one to one; The wafer (100) support (1) is used to support wafers (100) of different specifications, and when driving the wafer (100) of corresponding specifications to rotate around the rotation axis, the edge of the wafer (100) of corresponding specifications passes between the corresponding emitting lamp (311) and the photosensitive device (321) in sequence.

3. The wafer (100) notch detection device according to claim 2, characterized in that: The transmitting module also includes a control gate circuit, and the control gate circuit is used to control the on and off of the circuit where the transmitting lamp (311) is located according to the signal; The control gate circuit of each transmitting module is connected to the controller, and each transmitting module corresponds to the specification of the wafer (100) one by one; the controller is used to send a conduction signal to the control gate circuit of the corresponding transmitting module according to the specification of the wafer (100) placed on the wafer (100) support (1), and send a disconnection signal to the control gate circuits of other transmitting modules.

4. The wafer (100) notch detection device according to claim 2 or 3, characterized in that: It also includes a support frame (4); the sensor includes a transmitting plate (31) and a receiving plate (32); The transmitting plate (31) and the receiving plate (32) are both fixed on the supporting frame (4), and the transmitting plate (31) and the receiving plate (32) are arranged at an interval; The transmitting modules are all arranged on the transmitting board (31), and the receiving modules are all arranged on the receiving board (32).

5. The wafer (100) notch detection device according to claim 1, characterized in that: The transmitting module also includes a power supply module and a power supply voltage stabilizing circuit; The power supply module is used to supply power to the circuit where the emitting lamp (311) is located; The power supply voltage stabilizing circuit is used to stabilize the output voltage of the power supply module.

6. The wafer (100) notch detection device according to claim 1, characterized in that: The transmitting module also includes a first power amplifier circuit; the power supply module is connected to the transmitting lamp (311) via the first power amplifier circuit.

7. The wafer (100) notch detection device according to claim 1, characterized in that: The receiving module comprises a second power amplifier circuit, which is connected to the output end of the photosensitive device (321) to amplify the current or voltage output by the photosensitive device (321).

8. The wafer (100) notch detection device according to claim 1, characterized in that: The wafer (100) support member (1) is provided with a vacuum adsorption port (101) so as to adsorb the wafer (100) through the vacuum adsorption port (101).

9. The wafer (100) notch detection device according to claim 1, characterized in that: It also comprises a driving mechanism (2), wherein the driving mechanism (2) is used to drive the wafer (100) support (1) to rotate around a rotation axis.

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