Wafer pre-positioning method and device, and electronic equipment

Abstract

The present invention discloses a wafer pre-positioning method and device, and electronic equipment, the method comprising: obtaining a spatial voltage signal output by a wafer pre-positioning sensor assembly; the pre-positioning sensor assembly is arranged at the edge of the wafer; the edge of the wafer is provided with a positioning edge; the spatial voltage signal is converted into a time duty cycle signal according to a trigonometric proportional relationship; and the wafer is subjected to center pre-positioning and positioning edge pre-positioning according to the time duty cycle signal. The technical solution provided by the present invention can realize the positioning identification of a transparent wafer.

Description

Technical Field

[0001] The present invention relates to the field of display technology, and in particular to a wafer pre-positioning method and device, and electronic equipment. Background Art

[0002] Semiconductor production and testing equipment mostly have automatic transmission functions to achieve accurate material identification, feeding, processing and management. Among them, the wafer needs to be pre-positioned (positioning identification) during the measurement or transmission process, so that the corresponding measurement and processing can be carried out after pre-positioning. Positioning identification includes center (identified by xy coordinates) pre-positioning and angle (flat edge (FLAT) or notch (NOTCH)) pre-positioning. This process is called pre-positioning (PreAligner, PA).

[0003] In the past, silicon-based wafers were opaque, so the original PA equipment did not support transparent identification. However, the emerging compound semiconductors such as SiC and GaN cannot be positioned and identified because they are transparent. Summary of the invention

[0004] The embodiments of the present invention provide a wafer pre-positioning method and device, and electronic equipment to realize positioning and identification of a transparent wafer.

[0005] In a first aspect, an embodiment of the present invention provides a wafer pre-positioning method, comprising:

[0006] Acquiring a spatial voltage signal output by a pre-positioning sensor component of a wafer; the pre-positioning sensor component is disposed at an edge of the wafer; and a positioning edge is disposed at the edge of the wafer;

[0007] Converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship;

[0008] Center pre-positioning and positioning edge pre-positioning are performed on the wafer according to the time duty cycle signal.

[0009] In a second aspect, an embodiment of the present invention provides a wafer pre-positioning device, which is applicable to the wafer pre-positioning method provided by any embodiment of the present invention, including:

[0010] A signal acquisition module, used to obtain a spatial voltage signal output by a wafer pre-positioning sensor assembly;

[0011] A signal conversion module, used for converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship;

[0012] A pre-positioning module is used to perform center positioning and edge positioning on the wafer according to the time duty cycle signal.

[0013] In a third aspect, an embodiment of the present invention provides an electronic device, characterized in that it includes a pre-positioning control processor, wherein for any wafer, the pre-positioning control processor adopts the pre-positioning method described in any embodiment of the present invention to perform wafer pre-positioning.

[0014] In the present invention, the output of the pre-positioning sensor group is a spatial voltage signal, which can be converted into a time duty cycle signal according to a trigonometric proportional relationship, and the wafer is pre-positioned according to the time duty cycle signal. This avoids the problem of being unable to pre-position transparent wafers in the prior art, and does not require the use of a specific time duty cycle sensor for data collection, but rather uses a spatial voltage sensor for data collection, such as the Keyence IG028 sensor, and then converts the signal output by the spatial voltage sensor from a spatial variable to a time variable through the processing of a controller, thereby expanding the scope of application to wafers of various transparencies; effective positioning can be achieved in different practical machine models, with convenient application, low replacement cost, multi-model compatibility, and unified standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Output waveform diagram of a pre-positioning sensor for a non-transparent wafer in the prior art;

[0016] Figure 2 Output waveform diagram of a pre-positioning sensor of a transparent wafer in the prior art;

[0017] Figure 3 A schematic flow chart of a wafer pre-positioning method provided by an embodiment of the present invention;

[0018] Figure 4 A schematic diagram of a planar structure of a wafer provided by an embodiment of the present invention;

[0019] Figure 5 A schematic diagram of a planar structure of another wafer provided by an embodiment of the present invention;

[0020] Figure 6 A high-speed output waveform of a wafer time duty cycle PA provided by an embodiment of the present invention;

[0021] Figure 7 The spatial voltage PA output waveform of the wafer provided by the embodiment of the present invention;

[0022] Figure 8 The output waveform of the non-transparent wafer of the space voltage PA of the wafer provided by the embodiment of the present invention;

[0023] Fig. 9 The output waveform of the transparent wafer of the space voltage PA of the wafer provided by the embodiment of the present invention;

[0024] Fig.10A schematic structural diagram of a pre-positioning device provided by an embodiment of the present invention;

[0025] Fig.11 A waveform diagram of a wafer pre-positioning method provided by an embodiment of the present invention;

[0026] Fig.12 A waveform diagram of a wafer pre-positioning method provided by an embodiment of the present invention;

[0027] Fig.13 A schematic diagram of the structure of a small signal noise suppression processing circuit provided by an embodiment of the present invention;

[0028] Fig.14 A schematic structural diagram of a wafer pre-positioning device provided by an embodiment of the present invention;

[0029] Fig.15 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0031] In the past, silicon-based wafers were opaque, and the original PA equipment did not support transparent identification. However, for wafers formed by compound semiconductors such as SiC and GaN, which are commonly used today, the original PA equipment cannot work properly and needs to be modified. Specifically, a pre-positioning sensor is required during the measurement process. Figure 1 The waveform diagram is output by the pre-positioning sensor of the non-transparent wafer in the prior art. Figure 2 The present invention is a waveform diagram outputted by a pre-positioning sensor of a transparent wafer in the prior art. Figure 1 and Figure 2 , are waveforms of several nodes of charge coupled device (CCD) PA signal processing. A certain period T' of the waveform corresponds to a CCD photo imaging. The light distribution represents the spatial position of the wafer. For example, the low level is the case of full light (the wafer does not block the pre-positioning sensor), and the high level is the inherent black high level area (the wafer blocks the pre-positioning sensor). Figure 2 The high level of the middle waveform slowly decreases, which is the light distribution caused by the semi-transparency of the wafer. The small peak A1 in the middle is the black edge effect of the transparent wafer edge. Because for transparent or semi-transparent wafers, the edge of the wafer has poor light transmittance due to total reflection of light, which will form a black line. Figure 2 The small peak A1 is shown in FIG. Figure 1As shown in the figure, the native silicon wafer is fully shielded, and the level is all high to the edge of the wafer. Figure 2 It can be seen that the signal changes caused by wafer transparency will cause large fluctuations in the PA signal, which will make it difficult and inaccurate for the subsequent circuit to extract the location of the wafer edge, making it impossible to locate the wafer.

[0032] In order to solve the above problems, an embodiment of the present invention provides a wafer pre-positioning method. Figure 3 A schematic diagram of a process flow of a wafer pre-positioning method provided by an embodiment of the present invention. Figure 3 As shown, the method of this embodiment includes the following steps:

[0033] Step S110, obtaining a spatial voltage signal output by a pre-positioning sensor assembly of the wafer; the pre-positioning sensor assembly is disposed at an edge of the wafer; and a positioning edge is disposed at the edge of the wafer.

[0034] like Figure 4 and Figure 5 As shown, Figure 4 A schematic diagram of the planar structure of a wafer provided in an embodiment of the present invention. Figure 5 A schematic diagram of the planar structure of another wafer provided in an embodiment of the present invention. Figure 4 and Figure 5 The positioning edge 211 of the wafer 21 is shown in FIG. Figure 4 The positioning edge 211 shown in FIG. 2 is a NOTCH notch 212. Figure 5 The positioning edge 211 shown in the figure is a FLAT flat edge 213. The pre-positioning sensor assembly may include a plurality of pre-positioning sensors 26. The pre-positioning sensor assembly may be arranged at the edge of the wafer 21. When the wafer 21 rotates in a set direction, for example, in the L1 direction, the pre-positioning sensor 26 can output different signals when the wafer 21 covers the pre-positioning sensor 26 and when the pre-positioning sensor 26 is not covered, thereby pre-positioning the wafer 21 through the positioning edge 211.

[0035] Above Figure 1 and Figure 2 The PA output signal shown is based on multiple consecutive recordings of light distribution information, that is, an output signal of a time duty cycle type, which can be called a time duty cycle signal. Figure 6 The high-speed output waveform of a wafer time duty cycle PA provided by an embodiment of the present invention. Figure 1 Based on this, compress the time axis and get Figure 6 The continuous high-speed microscopic photography shown in the figure records the spatial position change of the wafer positioning edge at the light and CCD sensor, and the eccentricity value of the wafer and the position of the Flat / Notch mark are obtained through macroscopic algorithm analysis. Figure 6As shown in the macro envelope display, the slowly changing envelope A2 corresponds to the wafer eccentricity, and the rapidly changing envelope A3 corresponds to the wafer Flat / Notch mark position. There is also a PA output signal such as Figures 7 to 9 It characterizes the spatial position of the wafer based on recording the real-time and continuous voltage value generated by the edge of the wafer at the pre-positioning sensor component, which can also be called a spatial voltage signal. Figure 7 The spatial voltage PA output waveform of the wafer provided by the embodiment of the present invention is as follows: Figure 8 The output waveform of the non-transparent wafer of the space voltage PA of the wafer provided by the embodiment of the present invention is Fig. 9 The output waveform of the transparent wafer of the space voltage PA of the wafer provided by the embodiment of the present invention. Figure 7 As shown, the voltage sine curve A4 corresponds to the wafer eccentricity, and the peak A5 corresponds to the wafer Flat / Notch mark position. In other words, the sine curve reflects the eccentricity, and the peak corresponds to the positioning edge (notch mark or flat edge mark). Figure 8 Silicon wafers and Fig. 9 The transparent wafers in the figure all react to eccentricity through a sinusoidal curve, with the peaks corresponding to the notch marks.

[0036] Step S120: converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship.

[0037] Generally speaking, in the PA transparency transformation plan, the direct idea is to replace the sensor to support transparent film. For the spatial voltage type PA, there are products that support transparent films, such as Keyence IG028. You can directly replace the pre-positioning sensor component with Keyence IG028 and set it up. However, for the time duty cycle type PA, there is no direct reliability sensor available. Therefore, this embodiment proposes an IG028 U2P (U to P) solution, that is, the IG028 that supports GLS transparent film can be applied to the duty cycle type PA solution. The core idea is: convert the sampled spatial voltage signal into the time duty cycle signal required by the time duty cycle type PA in real time, complete the conversion of spatial voltage U to time duty ratio P, and realize it at high speed by the MCU microcontroller. Because the period of the signals output by the space voltage PA and the duty cycle PA is the same, and the identification changes of the positioning edge are synchronous, they have a certain proportional relationship. This embodiment converts the space voltage signal into a time duty cycle signal through a trigonometric proportional relationship, and completes the conversion of the space voltage U to the time proportion P at high speed in the single chip microcomputer, effectively improving the final pre-positioning rate and accuracy. Effectively realizing the transparent scheme transformation of the duty cycle PA scheme can realize universal transformation for many pre-positioning equipment manufacturers, and improve the practicality and reliability of the scheme.

[0038] Optionally, the MCU can be used to implement sampling based on the MA89G564 MCU. The ADC uses the MCU's built-in maximum 250ksps, 12-bit successive approximation ADC analog-to-digital converter, working in single-node mode, with a range of [0V, 5V], 4096 equal divisions, and a minimum resolution of 1.22mV. The MCU sampling rate is 32M / 6 / 2 / 24=111Ksps, that is, the sampling period is 9us. The sampling trigger can be set by T3OF overflow and taken every 15us (or other values ​​greater than 9us), or it can be triggered immediately when ADCS is started (continuous and uninterrupted multiple samplings for averaging).

[0039] Step S130 , performing center pre-positioning and positioning edge pre-positioning on the wafer according to the time duty cycle signal.

[0040] Fig.10 A schematic diagram of the structure of a pre-positioning device provided in an embodiment of the present invention. Optionally, before obtaining the spatial voltage signal output by the pre-positioning sensor assembly of the wafer 21, it may include: controlling the wafer 21 to be adsorbed on the rotating shaft 24, and controlling the rotating shaft 24 to rotate at a constant speed. In this embodiment, the wafer 21 can be adsorbed on the rotating shaft 24 through a vacuum tube, and the rotating shaft 24 can be controlled to rotate at a constant speed, then the spatial voltage signal output by the pre-positioning sensor assembly of the wafer.

[0041] After converting the spatial voltage signal into a precise time duty cycle signal, the pre-positioning device of the duty cycle PA can directly perform a pre-positioning operation through the time duty cycle signal. The pre-positioning operation can sequentially include center pre-positioning and positioning edge pre-positioning.

[0042] In the embodiment of the present invention, the output of the pre-positioning sensor group is a spatial voltage signal, which can be converted into a time duty cycle signal according to the trigonometric proportional relationship, and the wafer is pre-positioned according to the time duty cycle signal. This avoids the problem of being unable to pre-position transparent wafers in the prior art, and does not require the use of a specific time duty cycle sensor for data collection. Instead, data is collected through a spatial voltage sensor, such as the Keyence IG028 sensor, and then the signal output by the spatial voltage sensor is converted from a spatial variable to a time variable through the processing of the controller, expanding the scope of application to wafers of various transparencies; effective positioning can be achieved in different practical machine models, with convenient application, low replacement cost, multi-model compatibility, and unified standards.

[0043] The above is the core idea of ​​the present invention. The technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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.

[0044] Based on the above embodiments, Fig.10 As shown, the pre-positioning sensor assembly may include at least one pre-positioning sensor; the pre-positioning sensor includes a light emitter 22 and a receiver 23; the light emitter 22 and the receiver 23 are respectively arranged on both sides of the wafer 21. When the light emitter 22 emits light, if there is an obstruction of the wafer 21 between the light emitter 22 and the receiver 23, the receiver 23 cannot receive the light signal and output the first voltage; if there is no obstruction of the wafer 21 between the light emitter 22 and the receiver 23, the receiver 23 receives the light signal and outputs the second voltage. In this embodiment, the positioning edge of the wafer 21 is identified by the level signal output by the receiver 23. Optionally, the width d1 of the light emitter 22 may be slightly smaller than the width d2 of the receiver 23. It is convenient for the receiver 23 to fully receive the light emitted by the light emitter 22, further improve the accuracy of the output voltage value of the pre-positioning sensor group, thereby improving the accuracy of the spatial voltage signal, and finally achieving the accuracy of the pre-positioning of the transparent wafer.

[0045] Fig.11 A waveform diagram of a wafer pre-positioning method provided by an embodiment of the present invention. Fig.12 A waveform diagram of a wafer pre-positioning method provided in an embodiment of the present invention. Optionally, obtaining a spatial voltage signal output by a wafer pre-positioning sensor assembly may include: obtaining a voltage-time curve output by the wafer pre-positioning sensor assembly; the voltage-time curve includes a plurality of first pulses M1; the first voltage of the first pulse corresponds to a state in which the pre-positioning sensor assembly is completely blocked by the wafer; the second voltage between two adjacent first pulses M1 corresponds to a state in which the pre-positioning sensor assembly is completely exposed across the positioning edge; the first pulse M1 also includes a first rising edge s1 and a first falling edge s2; the voltage in the voltage-time curve is used as a spatial voltage signal. In this embodiment, during the rotation of the wafer 21, the pre-positioning sensor assembly generates a voltage-time curve. For the voltage-time curve, when the pre-positioning sensor assembly is completely blocked by the wafer, a fixed first voltage will be directly formed, and when the pre-positioning sensor assembly is completely exposed across the positioning edge, a fixed second voltage will be directly formed, and a variable voltage will be formed at the first rising edge s1 and the first falling edge s2 between the first voltage and the second voltage. In the process of converting the voltage-time curve into the time duty cycle curve (potential-time curve), it can be seen that the voltage-time curve and the time duty cycle curve have a certain geometric relationship. In this embodiment, the voltage in the voltage-time curve is used as the spatial voltage signal u, and the spatial voltage signal u is transformed in a geometric relationship to obtain the time duty cycle signal.

[0046] It should be noted that the variable voltage needs to perform the transformation between the spatial quantity and the temporal quantity. The present embodiment needs to focus on the spatial voltage signal u in the first rising edge s1 or the first falling edge s2, which is used to realize the conversion of the voltage-time curve into the potential-time curve, to realize the pre-positioning process of the transparent wafer, and to realize the transparent transformation of the duty cycle PA solution.

[0047] Optionally, if the pre-positioning sensor assembly is installed in a positive sequence, the spatial voltage signal on the first falling edge s2 of the first pulse M1 is output first, and then the spatial voltage signal on the first rising edge s1 of the first pulse M1 is output; if the pre-positioning sensor assembly is installed in a reverse sequence, the spatial voltage signal on the first rising edge s1 of the first pulse M1 is output first, and then the spatial voltage signal on the first falling edge s2 of the first pulse M1 is output. Figure 4 , this embodiment may include a plurality of linear receiving arrays arranged in sequence along the X direction. Exemplarily, along the X direction, the 1st to 1024th linear receiving arrays are arranged in sequence. In this embodiment, the positive sequence installation and the reverse sequence installation are the directions flipped along the X direction. Optionally, this embodiment may select the installation method in which the 1st to 1024th linear receiving arrays are arranged in sequence along the X direction as the positive sequence installation of the pre-positioning sensor assembly; along the X direction, the installation method in which the 1024th to 1st linear receiving arrays are arranged in sequence is the reverse sequence installation of the pre-positioning sensor assembly. Exemplarily, such as Fig.11 As shown, CCDout1 can be the output waveform (voltage-time curve) of the odd-numbered columns of the linear receiving array, and CCDout2 can be the output waveform (voltage-time curve) of the even-numbered columns of the linear receiving array. CCDout can refer to the output waveform (voltage-time curve) of any column of the linear receiving array. Fig.11 , when the pre-positioning sensor assembly is installed in the positive sequence, the spatial voltage signal on the first falling edge s2 of the first pulse M1 is output first, and then the spatial voltage signal on the first rising edge s1 is output. At this time, the first falling edge s2 of the first pulse M1 coincides with the time point of the second rising edge s3 of the second pulse M2 of the potential-time curve that needs to be generated in the end; continue to refer to 12, when the pre-positioning sensor assembly is installed in the reverse sequence, the voltage-time curve first outputs the spatial voltage signal on the first rising edge s1 of the first pulse M1, and then the spatial voltage signal on the first falling edge s2 of the first pulse M1 is output. At this time, the first rising edge s1 of the first pulse M1 coincides with the time point of the second falling edge s4 of the second pulse M2 of the potential-time curve that needs to be generated in the end. This embodiment can convert between spatial quantity and time quantity by collecting the spatial voltage signals on the first falling edge s2 and the first rising edge s1 of the first pulse M1, thereby effectively improving the conversion efficiency and improving the reliability of the pre-positioning of the transparent wafer.

[0048] Continue to refer Fig.11Optionally, converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship may include:

[0049] If the pre-positioning sensor assembly is installed in positive sequence, the spatial voltage signal u is converted into the time duty cycle signal y according to the following formula:

[0050]

[0051] Among them, U is the standard voltage of the wafer at the standard position; T is the fixed exposure period of the wafer; Y is the standard time duty cycle signal of the standard position of the wafer; the time points of Y and U are the same.

[0052] The voltage-time curves CCDout1 and CCDout2 output a light distribution photographic signal with a frame period of T. The second rising edge s3 of the second pulse M2 of the potential-time curve PW corresponds to the current wafer positioning edge position, and the exposure synchronization signal PX has a negative pulse in each period T. As the wafer positioning edge shakes, the second rising edge s3 of the second pulse M2 of PW forms a different time duty cycle signal y (a certain position); let the standard time duty cycle signal of the standard non-eccentricity be Y. If the pre-positioning sensor assembly is installed in a positive sequence, the wafer insertion action is from left to right, the corresponding shielding increases (first voltage), and the duty cycle of the second pulse M2 of PW decreases. Exemplarily, after the IG028CCD sensor is used in this embodiment, CCDout=5V (first voltage) when there is no wafer fully exposed on the extreme left, and CCDout=0V (second voltage) when it is fully shielded on the extreme right; and the voltage CCDout=U (the same as the time point of proportion Y) at the standard non-eccentric position, and the spatial voltage signal CCDout=u (corresponding to proportion y) at other above-mentioned certain positions y. Then, according to the trigonometric relationship (the starting 0V vertex is on the right of the figure), the above signal model has:

[0053]

[0054] Thus we get:

[0055] After T, Y and U are known, the spatial voltage signal u can be measured at any current position and quantified into the time proportion y in real time. Figure 8 and Fig. 9 IG028 sensor outputs the voltage corresponding to the spatial point. Therefore, in this embodiment, the MCU performs high-speed AD sampling, and then the PCA outputs the PW signal at high speed to the wafer pre-positioning device to improve the transformation efficiency.

[0056] Optionally, the program design uses a programmable counter array PCA, and can be set to a 16-bit timing mode for timing calculation, controlling the timing between the PX exposure signal and the PW cycle signal start edge output, that is, the PCA is responsible for strict frame synchronization. The capture of the exposure signal PX is realized by the INT0 interrupt, in which the initial synchronization of the ADC and PCA resources is also realized.

[0057] Continue to refer Fig.12 Optionally, converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship may include:

[0058] If the pre-positioning sensor components are installed in reverse order, the spatial voltage signal u is converted into the time duty cycle signal y according to the following formula:

[0059]

[0060] Among them, U is the standard voltage of the wafer at the standard position; Y is the standard duty cycle of the wafer at the standard position; the time points of Y and U are the same.

[0061] Similarly, the voltage-time curve CCDout outputs a light distribution photographic signal with a frame period of T, and the exposure synchronization signal PX has a negative pulse in each period T. The original CCD of this type of PA is reverse output, and the wafer insertion action is from right to left on the time axis, corresponding to the increase in shielding and the decrease in the duty cycle of the second pulse M2 of PW. Exemplarily, after the duty cycle type PA transparent transformation solution of this embodiment is replaced with the IG028CCD sensor, CCDout = 5V (first voltage) when there is no wafer fully exposed, and CCDout = 0V (second voltage) when it is fully shielded. Then from the signal model in the figure, according to the trigonometric relationship (the starting 0V vertex is on the left of the figure), we have:

[0062]

[0063] Thus we get:

[0064] That is, after knowing Y and U, the voltage u can be measured at any current position and quantified into the time proportion y in real time.

[0065] Optionally, performing center pre-positioning and positioning edge pre-positioning on the wafer according to the time duty cycle signal may include: generating a potential-time curve according to the time duty cycle signal; the potential-time curve includes a second pulse M2; the first potential (e.g., a high level) of the second pulse M2 corresponds to a state in which the pre-positioning sensor component is completely exposed across the positioning edge; the second potential (e.g., a low level) of the adjacent second pulse M2 corresponds to a state in which the pre-positioning sensor component is completely blocked by the wafer; the second pulse M2 also includes a second rising edge s3 and a second falling edge s4; the time duty cycle signal y is used to control the duty cycle of the second pulse M2 so that the first rising edge s1 and the second falling edge s4 are at the same time point, and the first falling edge s2 and the second rising edge s3 are at the same time point; and controlling the wafer to perform center pre-positioning and positioning edge pre-positioning according to the change speed of the potential-time curve. Specifically, for a high-speed potential-time curve, the center pre-positioning data of the wafer is obtained through a slowly changing envelope, and the positioning edge pre-positioning data of the wafer is obtained through a rapidly changing envelope. This embodiment quickly obtains a potential-time curve based on a voltage-time curve, converts a signal from a spatial quantity to a temporal quantity, and improves the accuracy of transparent wafer pre-positioning recognition.

[0066] Optionally, controlling the wafer to perform center pre-positioning and positioning edge pre-positioning according to the changing speed rule of the potential-time curve may include: determining the center of the wafer according to the changing speed rule of the potential-time curve, controlling the wafer to rotate around the center, and continuing to obtain the updated potential-time curve; positioning the positioning edge according to the updated potential-time curve.

[0067] Specifically, the machine 25 controls the mechanical arm to grab the wafer and place it between the light emitter 22 and the receiver 23. The machine 25 can determine the center of the wafer according to the detection data of multiple sets of pre-positioning sensors, and then control the wafer to move along the X-axis and / or Y-axis to determine the center of the wafer. The machine 25 is provided with a rotating shaft 24, controls the vacuum pump to adsorb the wafer on the rotating shaft 24 through the vacuum pipe, and the machine 25 controls the rotating motor to drive the rotating shaft to rotate so as to drive the wafer to rotate. Then, the machine 25 rotates the positioning edge of the wafer to the specified position according to the detection data of multiple sets of pre-positioning sensors, thereby completing the positioning of the wafer.

[0068] On the basis of the above-mentioned embodiments, the voltage sampling accuracy and time output minimum scale support in the wafer pre-positioning method of this embodiment are relatively high in accuracy; the bit width supports voltage range and time length: supports [0,5V] voltage, [0,100]% duty cycle; sampling rate design, precise timing synchronization, and high-speed operation: accurate to the us level.

[0069] Based on the above embodiments, Fig.13The schematic diagram of the structure of a small signal noise suppression processing circuit provided by an embodiment of the present invention is as follows. The spatial voltage signal CCDout can be subjected to noise reduction processing first to obtain a more accurate waveform, and then the spatial voltage signal is converted into a time duty cycle signal to further improve the accuracy of pre-positioning. Specifically, Fig.13 As shown, the small signal noise suppression processing circuit includes a bias follower module 31, a differential amplifier module 32 and a common direction amplifier module 33. The first input terminal of the small signal noise suppression processing circuit inputs the shielded ground Sin_GND=V2, and the second input terminal inputs the spatial voltage signal Sin=V1 sampled by the pre-position sensor. When the variable resistor RP1 is zero, the resistance values ​​of the resistors R1 and R2 are the same, and the resistance values ​​of the resistors R3 and R4 are the same, the first output voltage Vout=Vref+(V2-V1)R3 / R1=V2=Sin, and the common mode noise is suppressed. Finally, the second output voltage Sout=(1+RP2 / R6)Vout, when the variable resistor RP2 is zero, Sout=Sin, but at this time, the common mode noise has been removed.

[0070] Based on the same concept, an embodiment of the present invention further provides a wafer pre-positioning device, which is applicable to the wafer pre-positioning method provided by any embodiment of the present invention. Fig.14 As shown, Fig.14 A schematic diagram of the structure of a wafer pre-positioning device provided in an embodiment of the present invention. The wafer pre-positioning device may include:

[0071] The signal acquisition module 101 is used to acquire the spatial voltage signal output by the wafer pre-positioning sensor assembly;

[0072] A signal conversion module 102, used to convert the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship;

[0073] The pre-positioning module 103 is used to perform center positioning and edge positioning on the wafer according to the time duty cycle signal.

[0074] In the embodiment of the present invention, the output of the pre-positioning sensor group is a spatial voltage signal, which can be converted into a time duty cycle signal according to the trigonometric proportional relationship, and the wafer is pre-positioned according to the time duty cycle signal. This avoids the problem of being unable to pre-position transparent wafers in the prior art, and does not require the use of a specific time duty cycle sensor for data collection. Instead, data is collected through a spatial voltage sensor, such as the Keyence IG028 sensor, and then the signal output by the spatial voltage sensor is converted from a spatial variable to a time variable through the processing of the controller, expanding the scope of application to wafers of various transparencies; effective positioning can be achieved in different practical machine models, with convenient application, low replacement cost, multi-model compatibility, and unified standards.

[0075] An embodiment of the present invention further provides an electronic device. Fig.15 A schematic diagram of the structure of an electronic device provided in an embodiment of the present invention, the electronic device comprises a pre-positioning control processor 11, wherein for any wafer, the pre-positioning control processor 11 adopts the pre-positioning method described in any embodiment of the present invention to perform wafer pre-positioning.

[0076] Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices may also represent various forms of mobile devices, such as personal digital processing, single-chip computers, wearable devices (such as helmets, glasses, watches, etc.), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0077] The pre-positioning control processor 11 may be a variety of general and / or dedicated processing components with processing and computing capabilities. Some examples of the pre-positioning control processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any appropriate processor, controller, microcontroller, etc. The pre-positioning control processor 11 performs the various methods and processes described above, for example, a wafer pre-positioning method.

[0078] In some embodiments, the wafer pre-positioning method may be implemented as a computer program, which is tangibly contained in a computer-readable storage medium, such as a storage unit. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 10 via a ROM and / or a communication unit. When the computer program is loaded into the RAM and executed by the pre-positioning control processor 11, one or more steps of the wafer pre-positioning method described above may be performed. Alternatively, in other embodiments, the pre-positioning control processor 11 may be configured to perform the wafer pre-positioning method in any other appropriate manner (e.g., by means of firmware).

[0079] Computer programs for implementing the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that when the computer program is executed by the processor, the functions / operations specified in the flow chart and / or block diagram are implemented. The computer program may be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0080] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A wafer pre-positioning method, characterized in that: include: Acquiring a spatial voltage signal output by a pre-positioning sensor component of a wafer; the pre-positioning sensor component is disposed at an edge of the wafer; The edge of the wafer is provided with a positioning edge; Converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship; performing center pre-positioning and positioning edge pre-positioning on the wafer according to the time duty cycle signal; Obtaining a spatial voltage signal output by a wafer pre-positioning sensor assembly, including: Obtaining a voltage-time curve output by a wafer pre-positioning sensor component; the voltage-time curve includes a plurality of first pulses; a first voltage of the first pulse corresponds to a state in which the pre-positioning sensor component is completely blocked by the wafer; a second voltage between two adjacent first pulses corresponds to a state in which the pre-positioning sensor component is completely exposed across the positioning edge; the first pulse also includes a first rising edge and a first falling edge; Taking the voltage in the voltage-time curve as a spatial voltage signal; Converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship includes: If the pre-positioning sensor assembly is installed in a positive sequence, the spatial voltage signal u is converted into a time duty cycle signal y according to the following formula: ； Wherein, U is the standard voltage of the wafer at the standard position; T is the fixed exposure period of the wafer; Y is the standard time duty cycle signal of the standard position of the wafer; the time point of Y is the same as that of U; Converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship includes: If the pre-positioning sensor components are installed in reverse order, the spatial voltage signal u is converted into a time duty cycle signal y according to the following formula: ； Among them, U is the standard voltage of the wafer at the standard position; Y is the standard duty cycle of the wafer at the standard position; the time points of Y and U are the same.

2. The wafer pre-positioning method according to claim 1, characterized in that: Before obtaining the spatial voltage signal output by the wafer pre-positioning sensor assembly, it includes: The wafer is controlled to be adsorbed on the rotating shaft, and the rotating shaft is controlled to rotate at a constant speed.

3. The wafer pre-positioning method according to claim 1, characterized in that: If the pre-positioning sensor assembly is installed in a positive sequence, the spatial voltage signal on the first falling edge of the first pulse is output first, and then the spatial voltage signal on the first rising edge of the first pulse is output; If the pre-positioning sensor components are installed in reverse order, the spatial voltage signal on the first rising edge of the first pulse is output first, and then the spatial voltage signal on the first falling edge of the first pulse is output.

4. The wafer pre-positioning method according to claim 1, characterized in that: Performing center pre-positioning and positioning edge pre-positioning on the wafer according to the time duty cycle signal includes: A potential-time curve is generated according to the time duty cycle signal; the potential-time curve includes a second pulse; a first potential of the second pulse corresponds to a state in which the pre-positioning sensor component is completely exposed across the positioning edge; a second potential adjacent to the second pulse corresponds to a state in which the pre-positioning sensor component is completely blocked by the wafer; the second pulse also includes a second rising edge and a second falling edge; the time duty cycle signal is used to control the duty cycle of the second pulse so that the first rising edge and the second falling edge are at the same time point, and the first falling edge and the second rising edge are at the same time point; The wafer is controlled to perform center pre-positioning and positioning edge pre-positioning according to the changing speed rule of the potential-time curve.

5. The wafer pre-positioning method according to claim 4, characterized in that: Controlling the wafer to perform center pre-positioning and positioning edge pre-positioning according to the changing speed rule of the potential-time curve includes: Determine the center of the wafer according to the changing speed rule of the potential-time curve, control the wafer to rotate around the center, and continue to obtain the updated potential-time curve; The positioning edge is positioned according to the changing speed rule of the updated potential-time curve.

6. The wafer pre-positioning method according to claim 1, characterized in that: The pre-positioning sensor assembly includes at least one pre-positioning sensor; The pre-positioning sensor comprises a light emitter and a receiver; the light emitter and the receiver are respectively arranged on two sides of the wafer.

7. A wafer pre-positioning device, characterized in that: The wafer pre-positioning method according to any one of claims 1 to 6 comprises: A signal acquisition module, used to obtain a spatial voltage signal output by a wafer pre-positioning sensor assembly; A signal conversion module, used for converting the spatial voltage signal into a time duty cycle signal according to a trigonometric proportional relationship; A pre-positioning module is used to perform center positioning and edge positioning on the wafer according to the time duty cycle signal.

8. An electronic device, characterized in that: It comprises a pre-positioning control processor, wherein, for any wafer, the pre-positioning control processor adopts the pre-positioning method described in any one of claims 1 to 6 to perform wafer pre-positioning.

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