Para-position detection method used in polypeptide biochip synthesis process

Abstract

The invention discloses a para-position detection method in a synthesis process of a thousand polypeptide biochip. The alignment detection method comprises the following steps: processing a selected area of a wafer to form a first alignment identifier; coating photoresist on a selected area of the wafer; exposing the photoresist, and locally heating a selected area of the wafer so as to form a second alignment mark on the photoresist; and measuring to obtain a first distance X1 between the first alignment mark and the second alignment mark in the first direction and a second distance Y1 between the first alignment mark and the second alignment mark in the second direction, and evaluating the overlay deviation of the wafer according to difference values (X1-X) and (Y1-Y) between the measured maximum and minimum values X1 and Y1 and standard values X and Y. According to the invention, alignment detection can be carried out on the overlay deviation of the wafer after exposure and before heat treatment, and the related wafer can be reworked in time after the overlay deviation is found, so that the product yield is greatly improved, and the wafer productivity is increased.

Description

Technical Field

[0001] The invention particularly relates to a method for detecting a position in a polypeptide biochip synthesis process, belonging to the technical field of chip detection. Background Art

[0002] Peptide biochip is a technical platform for high-throughput protein analysis and screening. At present, there are three main methods for preparing peptide microarray chips by in-situ synthesis, namely, photolithography synthesis method, spotting method (SPOT) and based on inkjet printing method. Among them, photolithography synthesis method is the method with the most technical application and market potential among the three technologies. The method firstly makes the photoresist with photoacid generator spin-coated on the wafer in advance react chemically to produce hydrogen ions by illumination, and then the chain reaction produced by the subsequent heat treatment process makes the hydrogen ions reach a specific concentration, so that the pretreated wafer is exposed to active sites, and finally amino acids are connected thereon to construct the peptide sequence.

[0003] However, in the lithography synthesis process route, the detection of overlay deviation of lithography technology has always been a difficulty of this technology platform. The difficulty lies in the following two points: 1) This process is different from the lithography technology in the integrated circuit process. There is no actual development process, and the actual lithography alignment result cannot be observed; 2) There are many lithography layers and the fault tolerance is small. Therefore, it is only possible to judge whether the overlay is accurate by the shadow formed by the photosensitizer after heat treatment. The reasons for the formation of the shadow are as follows: After the exposure / heat treatment link, a large amount of acidic ions are generated in the exposure area, and the photoresist material in the exposure / non-exposure area changes, which leads to a difference in the thickness of the photoresist surface. When observing with a microscope, the shadow due to the thickness difference can be observed. However, after the heat treatment, the chain reaction has actually occurred, and the wrong active point position on the entire wafer has been exposed. At this time, even if the overlay deviation is found, it cannot be repaired, so the detection is meaningless. Therefore, it is very necessary to develop a detection method and system that can detect overlay deviation after exposure and before heat treatment. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for detecting overlay deviation after exposure and before heat treatment during the synthesis of a polypeptide biochip, thereby overcoming the deficiencies in the prior art.

[0005] To achieve the aforementioned object of the invention, the present invention provides a method for detecting a position in the synthesis process of a polypeptide biochip, comprising:

[0006] Processing a first alignment mark in a selected area of ​​the wafer;

[0007] Covering the selected area of ​​the wafer with a photoresist containing a photoacid generator, and making the photoresist cover the first alignment mark;

[0008] Exposing the photoresist located in a selected area of ​​the wafer, and locally heating the selected area of ​​the wafer, thereby forming a second alignment mark on the photoresist;

[0009] Measure and obtain a first distance X1 between the first alignment mark and the second alignment mark in the first direction, and a second distance Y1 between the first alignment mark and the second alignment mark in the second direction, obtain differences (X1-X), (Y1-Y) between the measured values ​​X1, Y1 and the standard values ​​X, Y, and evaluate the overlay deviation of the wafer based on the differences (X1-X), (Y1-Y).

[0010] Compared with the prior art, the present invention provides an alignment detection method for use in the synthesis process of a polypeptide biochip, which can perform alignment detection on the overlay deviation of a wafer after exposure and before heat treatment, and can promptly rework the relevant wafer after the overlay deviation is discovered, thereby helping to improve product yield and increase wafer production capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the structure of a position detection system used in the synthesis process of a polypeptide biochip provided in Example 1 of the present invention;

[0012] Figure 2 It is a side view of a position detection system used in the synthesis process of a polypeptide biochip provided in Example 1 of the present invention;

[0013] Figure 3 This is a schematic diagram of the structure of a position detection system used in the synthesis process of a polypeptide biochip provided in Example 1 of the present invention;

[0014] Figure 4 It is a schematic structural diagram of a wafer loading tray provided in Embodiment 1 of the present invention;

[0015] Figure 5 is a schematic structural diagram of a wafer fixing unit provided in Embodiment 1 of the present invention;

[0016] Figure 6 is a schematic diagram of the structure of the wafer to be inspected;

[0017] Figure 7 It is a schematic diagram of the collected image of the wafer alignment inspection area. DETAILED DESCRIPTION

[0018] In view of the deficiencies in the prior art, the inventor of this case has proposed the technical solution of the present invention after long-term research and extensive practice. The technical solution, its implementation process and principle will be further explained as follows.

[0019] The present invention provides a method for detecting a position in the process of synthesizing a polypeptide biochip, comprising:

[0020] Processing a first alignment mark in a selected area of ​​the wafer;

[0021] Covering the selected area of ​​the wafer with a photoresist containing a photoacid generator, and making the photoresist cover the first alignment mark;

[0022] Exposing the photoresist located in a selected area of ​​the wafer, and locally heating the selected area of ​​the wafer, thereby forming a second alignment mark on the photoresist;

[0023] Measure and obtain a first distance X1 between the first alignment mark and the second alignment mark in the first direction, and a second distance Y1 between the first alignment mark and the second alignment mark in the second direction, obtain differences (X1-X), (Y1-Y) between the measured values ​​X1, Y1 and the standard values ​​X, Y, and evaluate the overlay deviation of the wafer based on the differences (X1-X), (Y1-Y).

[0024] Further, when (X1-X) and (Y1-Y) are both less than the specified value, it means that the overlay of the wafer is accurate. Otherwise, it means that the overlay of the wafer is inaccurate and the posture of the wafer needs to be adjusted. Specifically, the specified value is within 0.5μm. Preferably, the specified value can be 0.1-5μm.

[0025] Furthermore, the first alignment mark includes a first mark and a second mark, the second alignment mark includes a third mark and a fourth mark, the first distance is a straight-line distance between the first mark and the third mark along the first direction, and the second distance is a straight-line distance between the second mark and the fourth mark along the second direction.

[0026] Further, the first mark is a short line segment extending along the second direction, and the second mark is a short line segment extending along the first direction.

[0027] Further, the first mark and the second mark are arranged to intersect with each other, or one of the first mark and the second mark is arranged to intersect with an extension line of the other.

[0028] Further, the first mark and the second mark intersect vertically, or one of the first mark and the second mark intersects vertically with an extension line of the other.

[0029] Furthermore, the first alignment mark is a cross mark.

[0030] Furthermore, the first direction is perpendicular to the second direction.

[0031] Furthermore, the third mark is a short line segment extending along the second direction, and the fourth mark is a short line segment extending along the first direction.

[0032] Further, the third mark and the fourth mark are arranged to cross each other, or one of the third mark and the fourth mark is arranged to cross each other with an extension line of the other.

[0033] Further, the third mark and the fourth mark intersect vertically, or one of the third mark and the fourth mark intersects vertically with an extension line of the other.

[0034] Furthermore, the second alignment mark is a shadow pattern formed after the selected area of ​​the wafer is heated, and the third mark and the fourth mark are two adjacent sides of the shadow pattern.

[0035] Furthermore, the alignment detection method used in the synthesis process of the polypeptide biochip includes: processing a plurality of the first alignment marks in selected areas of the wafer, exposing the photoresist located in the plurality of selected areas of the wafer, and locally heating the plurality of the selected areas of the wafer, thereby forming a plurality of the second alignment marks on the photoresist.

[0036] Furthermore, the first alignment mark is located on a cutting path of the wafer.

[0037] Furthermore, a plurality of the first corresponding marks are distributed at the vertices of a polygon.

[0038] Furthermore, the alignment detection method used in the synthesis process of the polypeptide biochip specifically includes: using a graphic mask to assist in exposing the photoresist located in the selected area of ​​the wafer, thereby forming an exposure pattern on the photoresist located in the selected area of ​​the wafer, and the exposure pattern is the same as the second alignment mark and the pattern on the mask.

[0039] Furthermore, the alignment detection method used in the synthesis process of the polypeptide biochip specifically includes: first adjusting the wafer formed with the first alignment mark to a selected posture, and then exposing the photoresist with the assistance of the graphic mask, wherein when the wafer is in the selected posture, at least part of the first alignment mark corresponds to the selected area.

[0040] Furthermore, the alignment detection method for the polypeptide biochip synthesis process specifically includes: rotating the wafer around the θ axis and / or translating in the XY plane to adjust the wafer to the selected posture.

[0041] Furthermore, the alignment detection method used in the polypeptide biochip synthesis process specifically includes: acquiring an image of the wafer, and extracting edge position information and center position information of the wafer displayed in the image, comparing the edge position information and center position information with preset position information, and adjusting the posture of the wafer until the edge position information and center position information meet the standard position information.

[0042] The technical solution, its implementation process and principles, etc. will be further explained below in conjunction with the accompanying drawings. Unless otherwise specified, the photoresist, mask, linear actuator for linear drive, θ-axis actuator for rotation, camera, controller and numerical control circuits, identification / detection programs, etc. used in the embodiments of the present invention are all known to those skilled in the art and can be purchased commercially, so no specific limitation is made here.

[0043] Example 1

[0044] See also Figure 1 , Figure 2 and Figure 3 A positioning detection system for use in a polypeptide biochip synthesis process includes a wafer fixing unit 200, a wafer position correction unit 300, a local heating unit 400, an image acquisition unit 500 and a control unit. The control unit is connected to the wafer position correction unit 300, the local heating unit 400 and the image acquisition unit 500, and is used to adjust the working state of the wafer position correction unit 300, the local heating unit 400 and the image acquisition unit 500, and the working state is achieved by adjusting working parameters.

[0045] Specifically, the wafer fixing unit 200 is at least used to carry and fix the wafer. More specifically, the wafer fixing unit 200 includes a wafer loading tray 210 and a wafer fixing mechanism. The wafer loading tray 210 has a fixed table surface. The wafer fixing mechanism is arranged on the wafer loading tray 210 and is used to limit / fix the wafer on the fixed table surface.

[0046] In a specific embodiment, the wafer fixing mechanism is a clamping mechanism, which fixes the wafer by clamping. More specifically, the clamping mechanism includes two or more clamping arms, which are arranged at intervals along the circumference of the wafer loading plate 210, and a restricted space is formed between the two or more clamping arms, and the wafer can be restricted / fixed in the restricted space. More specifically, part of the clamping arm can be flexible / elastic, and when the wafer is set in the restricted space and contacts with the clamping arm, the clamping arm is in an elastic compression state, or an elastic or flexible buffer can be provided between the clamping arm and the wafer loading plate 210, and when the wafer is set in the restricted space and contacts with the clamping arm, the buffer is in an elastic compression state, so that the wafer is more firmly restricted / fixed on the wafer loading plate 210 through the elastic restoring force of the clamping arm itself or the buffer.

[0047] In another specific embodiment, please refer to Figure 5 , the wafer fixing mechanism is a negative pressure generating mechanism 220, and the negative pressure generating mechanism 220 can fix the wafer by negative pressure adsorption. Specifically, the wafer loading plate 210 has an air flow channel 211 inside, and the fixed table is provided with air holes connected to the air flow channel 211. The negative pressure generating mechanism 220 is connected to the air flow channel 211, so that negative pressure is formed at the air holes. Under the action of the air pressure difference between the upper and lower sides of the wafer, the wafer is adsorbed and fixed on the fixed table. More specifically, there can be multiple air holes on the fixed table, and the multiple air holes can be distributed in an array. Specifically, the negative pressure generating mechanism can be a vacuum pump, etc.

[0048] Specifically, the wafer fixing unit 200 further includes a photoelectric sensor, which is disposed on the wafer loading tray 210 and is at least used to confirm whether the wafer is loaded and fixed on the wafer loading tray 210. The photoelectric sensor is also connected to the control unit. The number, model, distribution position, etc. of the photoelectric sensors are not specifically limited.

[0049] Specifically, the wafer position correction unit 300 is in driving cooperation with the wafer loading tray 210 and is at least used to drive the wafer loading tray 210 to perform linear motion along the X-axis direction, perform linear motion along the Y-axis direction and rotate around the θ-axis.

[0050] Specifically, the wafer position correction unit 300 includes a wafer position correction platform 310 and a θ-axis actuator 320. The θ-axis actuator 320 is arranged on the wafer position correction platform 310, and the wafer loading plate 210 is arranged on the θ-axis actuator 320. The wafer loading plate 210 can rotate around the θ-axis under the drive of the θ-axis actuator 320. The wafer loading plate 210 and the θ-axis actuator 320 as a whole can perform linear motion along the X-axis and Y-axis of a three-dimensional coordinate system under the drive of the wafer position correction platform 310.

[0051] Specifically, the wafer position correction platform 310 includes an X-axis linear actuator and a Y-axis linear actuator, and the X-axis linear actuator, the Y-axis linear actuator and the θ-axis actuator 320 are in transmission cooperation. More specifically, the X-axis linear actuator, the Y-axis linear actuator and the θ-axis actuator 320 are connected to the control unit.

[0052] Specifically, the local heating unit 400 is mainly used to heat a part of the wafer on the wafer loading plate 210. More specifically, the local heating unit 400 includes one or more heating mechanisms 410, each of which cooperates with only a local area of ​​the wafer and is in thermal contact with the local area of ​​the wafer to achieve local heating.

[0053] For details, please refer to Figure 4 One or more avoidance holes 212 are also provided on the fixed table top of the wafer loading plate 210. The heating mechanism 410 is arranged in the avoidance hole 212 and has no direct contact with the wafer loading plate 210. It can be understood that the area of ​​the radial cross-section of an avoidance hole 212 is larger than the area of ​​the radial cross-section of a heating mechanism 410. When a heating mechanism 410 is correspondingly arranged in an avoidance hole 212, there is a clearance fit between the heating mechanism 410 and the avoidance hole 212. These heating mechanisms have no contact interference with the wafer loading plate when performing the lifting movement, which can slow down the heat exchange between the heating area and the non-heating area of ​​the wafer.

[0054] Specifically, the local heating unit 400 further includes a Z-axis linear actuator, which is transmission-connected to the heating mechanism 410 and is at least used to drive the heating mechanism 410 to move along the Z-axis of a three-dimensional coordinate system. Accordingly, the avoidance hole 212 is a through hole that penetrates the wafer loading plate 210, and the heating mechanism 410 can pass through the avoidance hole 212 and contact the wafer under the drive of the Z-axis linear actuator, and separate from the wafer after completing the local heating process on the wafer. It should be noted that the Z-axis linear actuator is connected to the control unit.

[0055] Specifically, the local heating unit 400 includes a plurality of heating mechanisms 410, which are arranged at intervals, and a plurality of avoidance holes 212 are also arranged on the fixed table of the wafer loading plate 210, and the plurality of avoidance holes 212 are arranged at intervals, and each heating mechanism 410 corresponds to a avoidance hole 212; more specifically, the plurality of avoidance holes 212 are respectively distributed at a plurality of vertices of a polygon. Specifically, the heating mechanism 410 can be a resistance heating mechanism, etc. More specifically, the heating mechanism 410 can be a bump structure, and therefore, the heating mechanism can also be referred to as a heating bump.

[0056] Specifically, the image acquisition unit 500 is mainly used to acquire image information of the wafer and transmit the acquired image information to the control unit, and the control unit is also used to determine the posture and photolithography deviation of the wafer according to the image information of the wafer acquired by the image acquisition unit 500. More specifically, the image acquisition unit 500 can be a camera or the like.

[0057] Specifically, the alignment detection system for the polypeptide biochip synthesis process also includes a support frame 100, and a wafer position correction unit 300, a local heating unit 400, and an image acquisition unit 500 are installed on the support frame 100. More specifically, the support frame 100 includes a substrate stage 110 and an upper panel 120, and the upper panel 120 is arranged above the substrate stage 110 along the Z-axis direction of a three-dimensional coordinate system, and the substrate stage 110 and the upper panel 120 are fixed by a vertical plate or a column. More specifically, the wafer position correction platform 310 can be installed on the substrate stage 110. More specifically, an installation window that cooperates with the wafer loading disk 210 is provided on the upper panel 120, and the wafer loading disk 210 is correspondingly arranged at the installation window. Specifically, the camera can be fixed above the upper panel 120 and facing the installation table of the wafer loading disk 210.

[0058] Example 2

[0059] A method for detecting a position in a peptide biochip synthesis process comprises the following steps:

[0060] Processing a first alignment mark in a selected area of ​​the wafer;

[0061] Covering the selected area of ​​the wafer with a photoresist containing a photoacid generator, and making the photoresist cover the first alignment mark;

[0062] The wafer having the first alignment mark formed thereon is adjusted to a selected posture, wherein when the wafer is in the selected posture, at least a portion of the first alignment mark corresponds to a selected area to be locally heated (i.e., an area to be exposed);

[0063] Exposing the photoresist located in the selected area of ​​the wafer, and locally heating the selected area of ​​the wafer, thereby forming a second alignment mark on the photoresist;

[0064] Measure the first distance X1 between the first alignment mark and the second alignment mark in the first direction, and the second distance Y1 between the first alignment mark and the second alignment mark in the second direction, obtain the differences (X1-X), (Y1-Y) between the measured values ​​X1, Y1 and the standard values ​​X, Y, and evaluate the overlay deviation of the wafer based on the differences (X1-X), (Y1-Y).

[0065] Specifically, the alignment detection method used in the peptide biochip synthesis process includes: processing a plurality of first alignment marks in a selected area of ​​a wafer, exposing a photoresist located in a selected area of ​​the wafer, and locally heating the selected area of ​​the wafer, thereby forming a plurality of second alignment marks on the photoresist.

[0066] Specifically, the first alignment mark is located on the dicing path of the wafer. More specifically, a plurality of first corresponding marks are distributed at the vertices of a polygon.

[0067] Specifically, the first alignment mark includes a first mark and a second mark, the second alignment mark includes a third mark and a fourth mark, the first distance is the straight-line distance between the first mark and the third mark along the first direction, and the second distance is the straight-line distance between the second mark and the fourth mark along the second direction. More specifically, the first mark is a short line segment extending along the second direction, and the second mark is a short line segment extending along the first direction. As a preferred embodiment, the first mark and the second mark are arranged crosswise, or one of the first mark and the second mark is arranged crosswise with the extension line of the other. More specifically, the first mark and the second mark cross vertically, or one of the first mark and the second mark cross vertically with the extension line of the other. For example, the first alignment mark is a cross mark, that is, the first direction is perpendicular to the second direction.

[0068] Specifically, the second alignment mark is a shadow pattern formed after the selected area of ​​the wafer is heated, the third mark and the fourth mark are two adjacent sides of the shadow pattern, the third mark is a short line segment extending along the second direction, and the fourth mark is a short line segment extending along the first direction. Corresponding to the first alignment mark, the third mark and the fourth mark are arranged crosswise, or one of the third mark and the fourth mark is arranged crosswise with the extension line of the other. More specifically, the third mark and the fourth mark are perpendicularly crossed, or one of the third mark and the fourth mark is perpendicularly crossed with the extension line of the other.

[0069] Specifically, the alignment detection method used in the polypeptide biochip synthesis process specifically includes: collecting an image of the wafer, and extracting the edge position information and the center position information of the wafer displayed in the image, comparing the edge position information and the center position information with the preset position information, and rotating the wafer around the θ axis and / or translating in the XY plane to adjust the wafer to a selected posture until the edge position information and the center position information meet the standard position information.

[0070] Specifically, the alignment detection method used in the synthesis process of the polypeptide biochip specifically includes: using a graphic mask to assist in exposing the photoresist located in the selected area of ​​the wafer, thereby forming an exposure pattern on the photoresist located in the selected area of ​​the wafer, and the exposure pattern is the same as the second alignment mark and the pattern on the mask.

[0071] Specifically, the alignment detection method used in the polypeptide biochip synthesis process specifically includes: first adjusting the wafer with a first alignment mark to a selected posture, and then exposing the photoresist with the assistance of a graphic mask, wherein when the wafer is in the selected posture, at least part of the first alignment mark corresponds to the selected area.

[0072] Specifically, a method for alignment detection in the process of polypeptide biochip synthesis in this embodiment is implemented by using a system for alignment detection in the process of polypeptide biochip synthesis in Example 1, and the method for alignment detection in the process of polypeptide biochip synthesis specifically includes:

[0073] 1) A robot is used to place the exposed wafer on the wafer loading plate 210, and the wafer is fixed on the wafer loading plate 210 by suction. The wafer has been processed in advance in a selected area to form a first alignment mark (i.e., an overlay mark or a wafer alignment mark point) and is coated with a photoresist containing a photoacid generator, such as Figure 6 As shown, the area to be exposed on the wafer corresponds to the first alignment mark, and the first alignment mark is completely located in the exposed area. It can be understood that the exposed area is the selected area that needs to be locally heated later, that is, the heating area in the figure;

[0074] 2) The high-resolution camera of the image acquisition unit 500 is used to capture photos of the wafer, and the captured data is transmitted to the position controller of the control unit. The position controller extracts the data of the edge and center position of the wafer, and compares them with the standard values ​​set in advance, and feeds back the comparison results to the control unit. The control unit controls the working parameters of the position correction platform and the θ-axis actuator 320 according to the comparison results to adjust the position of the wafer, and repeats this process until the position of the wafer is adjusted to the preset position. It should be noted that, at the preset position, the multiple first alignment marks on the wafer correspond to the multiple avoidance holes 212 on the wafer loading plate 210 respectively;

[0075] 3) adjusting the wafer with the first alignment mark formed thereon to a selected posture, wherein when the wafer is in the selected posture, at least a portion of the first alignment mark corresponds to a selected area to be locally heated;

[0076] 4) The control unit controls the Z-axis linear actuator to operate, and causes the heating mechanism 410 (for example, the temperature of the heating mechanism 410 is set to 85°C in advance) to rise and pass through the avoidance hole 212 to come into thermal contact with the wafer, and the non-heating area of ​​the wafer is in contact with the wafer loading plate 210, and the temperature of the wafer loading plate 210 is approximately room temperature. After heating starts for a preset time, the Z-axis linear actuator drives the heating mechanism 410 to descend, and the heating surface of the heating mechanism 410 is separated from the wafer, and heating is stopped. It should be noted that the selected area of ​​the photoresist on the surface of the wafer after local heating forms a shadow pattern identical to the pattern on the mask, i.e., the aforementioned second comparison mark.

[0077] 5) The high-resolution camera of the image acquisition unit 500 is used to respectively acquire images of the four groups of alignment detection areas (i.e., the aforementioned selected areas) on the wafer (the acquired images are as follows: Figure 7 As shown), the collected image data is transmitted to the control unit for overlay deviation measurement: the first alignment mark on the wafer is compared with the second alignment mark on the mask during exposure of the layer, the first distance X1 in the first direction between the first alignment mark and the second alignment mark, and the second distance Y1 in the second direction between the first alignment mark and the second alignment mark are compared, and the differences (X1-X) and (Y1-Y) between the measured values ​​X1 and Y1 and the standard values ​​X and Y are obtained, and the overlay deviation of the wafer is evaluated based on the differences (X1-X) and (Y1-Y) to determine whether the wafer should proceed to the next process or be reworked. For example, when (X1-X) and (Y1-Y) are both within 5μm, the wafer can proceed to the next process, otherwise, it needs to be reworked until (X1-X) and (Y1-Y) are both within 5μm.

[0078] It should be understood that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting a position in the synthesis process of a polypeptide biochip, characterized in that: include: Processing a first alignment mark in a selected area of ​​the wafer; Covering the selected area of ​​the wafer with a photoresist containing a photoacid generator, and making the photoresist cover the first alignment mark; Exposing the photoresist and locally heating a selected area of ​​the wafer to form a second alignment mark on the photoresist; Measure and obtain a first distance X1 between the first alignment mark and the second alignment mark in the first direction, and a second distance Y1 between the first alignment mark and the second alignment mark in the second direction, obtain the differences (X1-X), (Y1-Y) between the measured values ​​X1, Y1 and the standard values ​​x, Y, and evaluate the overlay deviation of the wafer based on the differences (X1-X), (Y1-Y).

2. The method for detecting the position of a polypeptide during biochip synthesis according to claim 1, characterized in that: The first alignment mark includes a first mark and a second mark, the second alignment mark includes a third mark and a fourth mark, the first distance is a straight-line distance between the first mark and the third mark along the first direction, and the second distance is a straight-line distance between the second mark and the fourth mark along the second direction.

3. The method for position detection in the process of peptide biochip synthesis according to claim 2, characterized in that: The first mark is a short line segment extending along the second direction, and the second mark is a short line segment extending along the first direction; Preferably, the first mark and the second mark are arranged crosswise, or one of the first mark and the second mark is arranged crosswise with an extension line of the other; Preferably, the first mark and the second mark intersect vertically, or one of the first mark and the second mark intersects vertically with an extension line of the other; Preferably, the first alignment mark is a cross mark; Preferably, the first direction is perpendicular to the second direction.

4. The method for position detection in the process of peptide biochip synthesis according to claim 2, characterized in that: The third mark is a short line segment extending along the second direction, and the fourth mark is a short line segment extending along the first direction; Preferably, the third mark and the fourth mark are arranged crosswise, or one of the third mark and the fourth mark is arranged crosswise with an extension line of the other; Preferably, the third mark and the fourth mark intersect vertically, or one of the third mark and the fourth mark intersects vertically with an extension line of the other.

5. The method for position detection in the process of peptide biochip synthesis according to claim 4, characterized in that: The second alignment mark is a shadow pattern formed after the selected area of ​​the wafer is heated, and the third mark and the fourth mark are two adjacent sides of the shadow pattern.

6. The method for position detection in the process of peptide biochip synthesis according to claim 2, characterized in that: include: Processing a plurality of the first alignment marks in a selected area of ​​the wafer, and exposing the photoresist and locally heating the selected area of ​​the wafer to form a plurality of the second alignment marks on the photoresist; Preferably, the first alignment mark is located on a cutting path of the wafer; Preferably, a plurality of the first corresponding marks are distributed at the vertices of a polygon.

7. The method for position detection in the process of peptide biochip synthesis according to claim 1, characterized in that: Specifically include: The photoresist is exposed with the assistance of a patterned mask, so as to form an exposure pattern on the photoresist, and the exposure pattern is the same as the second alignment mark and the pattern on the mask.

8. The method for position detection in the process of peptide biochip synthesis according to claim 7, characterized in that: Specifically include: First, the wafer formed with the first alignment mark is adjusted to a selected posture, and then the photoresist is exposed with the assistance of the patterned mask, wherein when the wafer is in the selected posture, at least part of the first alignment mark corresponds to the selected area.

9. The method for position detection in the process of peptide biochip synthesis according to claim 8, characterized in that: The wafer is rotated about the θ axis and / or translated in the XY plane to adjust the wafer to the selected posture.

10. The method for position detection in the process of peptide biochip synthesis according to claim 8, characterized in that: Specifically include: Capture an image of the wafer, extract edge position information and center position information of the wafer displayed in the image, compare the edge position information and center position information with preset position information, and adjust the posture of the wafer until the edge position information and center position information meet the standard position information.

Images