Wafer positioning device and positioning method for electron beam exposure machine

Abstract

The present invention discloses a wafer positioning device and positioning method for an electron beam exposure machine, the device includes a wafer carrier and a wafer clamp; the wafer carrier includes a base plate, a film feed guide rail and a self-locking slope are symmetrically arranged on both sides of the base plate, the self-locking slope is located inside the film feed guide rail and close to a limiting wall, a first positioning boss is located inside the self-locking slope, the limiting wall and the film transfer port are relatively arranged at both ends of the base plate, and a limiting assembly is provided on the limiting wall to achieve wafer positioning in the X, Y and Rz directions; a fixture body of the wafer clamp is provided with a guide roller, a positioning roller and a second positioning boss; when the guide roller drives the wafer clamp to move along the film feed guide rail, the positioning roller drives the wafer clamp to first rise and then fall along the self-locking slope, and when the wafer clamp falls, the second positioning boss rests on the first positioning boss to achieve wafer positioning in the Z, Rx and Ry directions. The present invention has the characteristics of convenient operation and high positioning accuracy, and meets the special working condition use requirements of the electron beam exposure machine.

Description

Technical Field

[0001] The present invention belongs to the technical field of wafer positioning, and in particular relates to a wafer positioning device and a positioning method for an electron beam exposure machine and similar working conditions. Background Art

[0002] Electron beam lithography (EBLI) systems use an electron beam to directly expose photoresist-coated wafers or wafers. They hold a significant position and importance in the semiconductor process equipment sector. Compared to other semiconductor process equipment, EBLIs offer certain unique advantages. Because they can control the deflection of the electron beam during exposure, they offer exceptional flexibility and can create patterns without the need for a mask.

[0003] However, the ability to achieve accurate mapping requires very precise positioning methods and benchmarks. Therefore, the benchmark and coordinate system of the electron beam exposure machine are very critical, which also leads to the need for positioning of the wafer fixture, which is also an important function of the equipment carrier.

[0004] In electron beam equipment, the coordinate system is a very important part. The equipment relies on laser interferometer measurement to form the coordinate reference of the entire machine and identify the position of the workpiece stage (carrier stage). Figure 1 As shown, there are positioning marks on the stage, and their position relative to the measuring surface is fixed. Therefore, the stage position measured by the laser interferometer can be regarded as the coordinate position of the stage mark. There are also positioning marks on the wafer fixture, and the marks can be regarded as the origin of the fixture. The coordinate system between them can be established through the relative distance and angle relationship between the marks. Similarly, there are marks on the wafer to identify the relative distance between the wafer and the wafer fixture. The mark position on the wafer is the addressing reference for the exposure process. It can be seen that in the electron beam exposure machine, from the stage mark-wafer fixture mark-wafer mark, two coordinate transformations are carried out to construct the coordinate system of the equipment. Only when the two coordinate transformations are accurate can the high precision requirements of the equipment process be guaranteed.

[0005] In actual work use, these two relative coordinate transformations are different.

[0006] First, the coordinate conversion between the wafer fixture mark and the wafer mark needs to be determined in advance. Because the position of each wafer mark is different from the position of the wafer fixture mark, the relative coordinate distance between them is not exactly the same. During use, before the fixture with the wafer is placed into the equipment for the exposure process, it is necessary to operate on the pre-alignment table. First, the alignment measurement is performed under an optical microscope. Then, the relative coordinate distance between the coordinate position on the wafer and the coordinate position on the wafer fixture is recorded and measured using a manual adjustment platform with a mobile position measurement function. The relative coordinate conversion at this point can be easily and accurately achieved using the manual adjustment table.

[0007] Secondly, the coordinate conversion between the stage mark and the wafer fixture mark is measured inside the equipment, and the relative position must be kept constant during the exposure process where the workpiece stage moves frequently for a long time (an exposure cycle is often greater than 1 hour), otherwise the process accuracy index will have errors that cannot be detected during the process. Therefore, the key thing to ensure for the wafer fixture during equipment operation is that the relative position between the stage mark and the wafer fixture mark remains unchanged. In addition, since the fixture is used in conjunction with the electron beam exposure machine, each fixture can quickly perform coordinate conversion by identifying its number during operation. Unless it is necessary to measure the relative coordinates of the fixture mark again due to circumstances such as changing the mark, there is no need to measure the relative position internally again, which can greatly improve the working efficiency of the equipment. The premise for realizing automatic coordinate conversion of the fixture according to its number is that the position of the same fixture placed each time can be kept consistent from beginning to end, that is, for each fixture, its loading position on the stage needs to have extremely high repeatability and maintain relative position stability during the process.

[0008] However, it is not easy to ensure the relative position stability and high repeatability between the wafer stage and the wafer fixture. This is reflected in the high-precision requirements in multiple degrees of freedom, mainly the height (Z) and horizontality (Rx, Ry) requirements after positioning. At the same time, the positioning angle (Rz) must be kept as vertical as possible relative to the wafer feed direction. This is also an important basis for reducing the workload of coordinate correction. In addition, the height requirement (Z) also includes the horizontality requirement.

[0009] In terms of wafer fixture positioning, there are many methods in the prior art for detecting position or achieving repeated positioning. Among the methods for equipment to locate and identify certain specific components, there are methods that use CCD plus image processing for measurement and positioning, methods that use in-place detection devices or measuring devices for measurement and positioning, and methods that use structurally designed fixed positioning references to achieve repeated positioning. Using CCD plus graphic processing allows the position of each loading to be different, but it is necessary to perform an inspection before each process, which is a large workload for the equipment. In addition, this method is easy to process data in the X, Y, and Rz directions, but it is difficult to achieve accurate detection in terms of height and flatness. The method of measuring and positioning by in-place detection devices or measuring devices does not have high accuracy using conventional detection methods (such as photoelectric switches, micro switches, etc.). If laser ranging methods are used, the cost (component material cost, installation space cost) is too high, and it increases the complexity of the equipment and reduces reliability. Summary of the Invention

[0010] The technical problem to be solved by the present invention is mainly to meet the high repeatability positioning accuracy requirements of the electron beam exposure machine for wafer clamp positioning, while meeting the process environment requirements of electron beam exposure for low magnetism (magnetic field will cause electron beam deflection) and low heat (temperature changes will cause thermal deformation errors), and provide a wafer positioning device and positioning method for electron beam exposure machine with compact structure, simple operation and high repeatability positioning accuracy.

[0011] To achieve the above object, the present invention can adopt the following technical solutions:

[0012] A wafer positioning device for an electron beam exposure machine, comprising a wafer stage and a wafer clamp; the wafer stage comprises a base plate, and a film feed guide rail, a self-locking slope, a first positioning boss, a limit wall and a film transfer port arranged on the base plate, the two film feed guide rails and the two self-locking slopes being symmetrically arranged on both sides of the base plate, the self-locking slopes being trapezoidal in structure, the self-locking slopes being located on the inner side of the film feed guide rails and close to the limit wall, a plurality of the first positioning bosses being evenly distributed on the base plate and located on the inner side of the self-locking slopes, the limit wall and the film transfer port being relatively arranged at both ends of the base plate, and limit assemblies being provided on both sides of the limit wall for realizing the positioning of the wafer clamp carrying the wafer in the X, Y and Rz directions; the The wafer clamp includes a clamp body, on which a guide roller, a positioning roller and a second positioning boss are provided. The guide roller matches the film feed guide rail and is used to assist the wafer clamp in carrying the wafer in and out of the wafer stage. The positioning roller matches the self-locking slope, and the first positioning boss matches the second positioning boss. When the guide roller drives the wafer clamp to move from the film transfer port along the film feed guide rail toward the limit wall, the positioning roller drives the wafer clamp to first rise and then fall along the self-locking slope. When the wafer clamp descends along the self-locking slope, the second positioning boss stays on the first positioning boss to realize the positioning of the wafer clamp carrying the wafer in the Z, Rx and Ry directions.

[0013] As a further improvement of the present invention, one side of the limiting wall is a V-shaped boss with the pointed corner facing forward, and fixed reference columns are installed on the inclined surfaces on both sides of the V-shaped boss. The other side of the limiting wall is a rectangular boss, and an adjustable reference column is provided on the end face of the rectangular boss facing the film transmission port.

[0014] As a further improvement of the present invention, a recessed V-shaped notch is provided on one side of the end of the clamp body, and fixed bosses are installed on the inclined surfaces on both sides of the V-shaped notch; a recessed rectangular notch is provided on the other side of the end of the clamp body, and a horizontal boss is installed on the rectangular notch; the fixed boss matches the fixed reference column, and the horizontal boss matches the adjustable reference column to realize the positioning of the wafer in the X, Y and Rz directions.

[0015] As a further improvement of the present invention, the film feed guide rail is in a right angle shape, and the guide rollers include lateral guide rollers and bottom guide rollers, the lateral guide rollers move along the sides of the film feed guide rail, and the bottom guide rollers move along the bottom of the film feed guide rail.

[0016] As a further improvement of the present invention, a mounting boss is further provided on the bottom plate. The mounting boss is located outside the film feed guide rail and is used to mount a reflector.

[0017] As a further improvement of the present invention, a mounting groove is further provided on the base plate, and the mounting groove is located in the middle of the base plate. The mounting groove is used to accommodate and install a locking device to provide locking force for the positioned wafer clamp.

[0018] As a further improvement of the present invention, a marking mounting seat is further provided on the bottom plate for fixing the marking silicon wafer.

[0019] As a further improvement of the present invention, three of each of the first positioning bosses and the second positioning bosses are provided to achieve three-point determination of the plane.

[0020] As a general technical concept, the present invention also provides a positioning method applicable to the wafer positioning device for the electron beam exposure machine, comprising the following steps:

[0021] Step S1: Under the push of the wafer transfer robot, the side guide rollers and the bottom guide rollers drive the wafer clamp to move forward along the wafer feed guide rail;

[0022] Step S2: When the wafer clamp moves to the position of the self-locking slope, the positioning roller contacts the surface of the self-locking slope, and the wafer clamp begins to rise along the upper ramp of the self-locking slope and leaves the bearing surface of the wafer feed guide rail;

[0023] Step S3: After the positioning roller passes the highest plane of the self-locking slope, the wafer clamp begins to move forward and downward along the downward slope of the self-locking slope, and the second positioning boss stops on the first positioning boss. At this time, the fixed boss and the fixed reference column, as well as the horizontal boss and the adjustable reference column, maintain contact;

[0024] Step S4: Use the locking device on the bottom plate to fix the wafer clamp so that the wafer clamp rests against the limit wall, and achieve high-precision repeated positioning through the position reference of the reference columns on both sides of the limit wall.

[0025] As a further improvement of the present invention, in step S1, when the lateral guide rollers and the bottom guide rollers move along the film feed guide rail, the positioning rollers are in a suspended state.

[0026] Compared with the prior art, the advantages of the present invention are:

[0027] 1. The wafer positioning device for an electron beam exposure machine of the present invention is based on the demand of the electron beam exposure machine for high-precision positioning of the wafer clamp, and a wafer stage structure is designed to cooperate to achieve high-precision positioning of the wafer clamp. Specifically, two film feed guide rails and two self-locking slopes are symmetrically arranged on both sides of the wafer stage bottom plate, and the self-locking slope is a trapezoidal structure. The self-locking slope is arranged on the inner side of the film feed guide rail and close to the limit wall, and then a plurality of first positioning bosses are evenly distributed on the bottom plate and located on the inner side of the self-locking slope, and limit assemblies are arranged on both sides of the limit wall; correspondingly, a guide roller, a positioning roller and a second positioning boss are arranged on the fixture body of the wafer clamp, the guide roller matches the film feed guide rail, the positioning roller matches the self-locking slope, and the first positioning boss matches the second positioning boss; when the guide roller drives As the wafer clamp moves from the film transfer port along the film feed guide toward the limit wall, the positioning roller drives the wafer clamp to first rise and then fall along the self-locking slope. As the wafer clamp descends along the self-locking slope, the second positioning boss stays on the first positioning boss. The positioning of the wafer in the X, Y and Rz directions is achieved by utilizing the limit components on both sides of the limit wall. The positioning of the wafer in the Z, Rx and Ry directions is achieved by utilizing the cooperation of the first positioning boss and the second positioning boss. The present invention achieves high repeatability positioning accuracy by adopting a fixed position, does not require additional electrical components, is simpler for the equipment, and has higher long-term reliability. Ultimately, high-precision positioning of the wafer in the Z, Rz, Rx and Ry degrees of freedom is achieved, meeting the special working environment requirements of the electron beam exposure machine.

[0028] 2. The wafer positioning device for the electron beam exposure machine of the present invention sets the self-locking slope as a trapezoidal structure with ups and downslopes. The trapezoidal parts and the lifting rollers are used to first raise the wafer clamp to a certain height during the conveying process, and then lower it to the positioning boss to limit the Z-direction freedom. At the same time, the horizontal reference is constrained by the limit wall. The ups and downslope action design greatly reduces the relative friction between the Z-direction contact parts, which is more conducive to ensuring long-term reliability.

[0029] 3. The wafer positioning method for an electron beam exposure machine of the present invention adopts multiple sets of guide rollers to carry out the wafer transfer process before the positioning action, thereby improving the smoothness of the wafer transfer process and reducing the relative friction during the wafer transfer process. At the same time, the key components related to the uphill and downhill actions can be kept suspended during the wafer transfer process through the rolling of the guide wheels, thereby avoiding the loss of the reference features and further strengthening the guarantee of positioning accuracy and long-term reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the coordinate transformation relationship of the electron beam exposure machine;

[0031] Figure 2 A schematic diagram of the structural principle of a wafer positioning device in a specific embodiment of the present invention;

[0032] Figure 3 Schematic diagram of the bottom structure principle of the wafer clamp in a specific embodiment of the present invention;

[0033] Figure 4 Schematic diagram of the cross section of the slide stage and the principle of up and down slope motion in a specific embodiment of the present invention;

[0034] Figure 5 A schematic diagram of a process for wafer positioning in a specific embodiment of the present invention;

[0035] Legend: 100, wafer carrier; 101, base plate; 102, film feed guide; 103, self-locking slope; 104, first positioning boss; 105, limiting wall; 106, fixed reference column; 107, adjustable reference column; 108, film transfer port; 200, wafer clamp; 201, clamp body; 202, lateral guide roller; 203, bottom guide roller; 204, positioning roller; 205, second positioning boss; 206, fixed boss; 207, horizontal boss; 301, mounting boss; 302, mounting slot; 303, marking mounting seat. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the scope of protection of the present invention is not limited thereby.

[0037] In the description of the present invention, it should be understood that the terms "side", "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0038] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or suggesting 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 one or more of the features. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0039] Example 1

[0040] like Figures 2 to 4As shown, the wafer positioning device for an electron beam exposure machine of the present invention includes a wafer stage 100 and a wafer clamp 200. The wafer stage 100 includes a base plate 101, and a film feed guide rail 102, a self-locking slope 103, a first positioning boss 104, a limiting wall 105 and a wafer transfer port 108 arranged on the base plate 101. The film feed guide rail 102 is a structure that constrains the forward direction of the wafer clamp 200 and guides its movement when it is transferred to the wafer stage 100. A pair of film feed guide rails 102 are respectively installed on both sides of the wafer stage 100, remain parallel to each other, and are perpendicular to the wafer transfer port 108. The self-locking slope 103 is a part of a trapezoidal structure, and the height of the top of the trapezoidal structure is greater than the thickness of the bottom of the film feed guide rail 102. The self-locking slope 103 is located on the inner side of the film feed guide rail 102 and close to the limiting wall 105, and is used to lift and lower the wafer clamp. A plurality of first positioning bosses 104 are evenly distributed on the bottom plate 101 and are located on the inner side of the self-locking slope 103. The limiting walls 105 and the film transfer port 108 are relatively arranged at the two ends of the bottom plate 101. Limiting components are provided on both sides of the limiting walls 105 to realize the positioning of the wafer clamp 200 carrying the wafer in the X, Y and Rz directions. The wafer clamp 200 includes a clamp body 201. The clamp body 201 is provided with a guide roller, a positioning roller 204 and a second positioning boss 205. The guide roller matches the film feed guide 102 and is used to assist the wafer clamp 200 in carrying the wafer in and out of the wafer carrier 100. The positioning roller 204 matches the self-locking slope 103. The first positioning boss 104 matches the second positioning boss 205. Figure 4 As shown, when the guide roller drives the wafer clamp 200 to move from the film transfer port 108 along the film feed guide rail 102 toward the limiting wall 105, the positioning roller 204 drives the wafer clamp 200 to first rise and then fall along the self-locking slope 103. In the process of the wafer clamp 200 descending along the self-locking slope 103, the second positioning boss 205 stays on the first positioning boss 104 to realize the positioning of the wafer clamp 200 carrying the wafer in the Z, Rx and Ry directions.

[0041] In this embodiment, three first positioning bosses 104 and three second positioning bosses 205 are provided to achieve three-point plane determination and improve positioning accuracy. Positioning bosses 104 can be inlaid with sapphire glass or directly machined. The three positioning bosses 104 must be of the same height and remain in the same plane. The assembly accuracy or machining accuracy must be 1 μm, which can also be determined based on the positioning accuracy requirements of the wafer.

[0042] In this embodiment, based on the demand for high-precision positioning of the wafer clamp by the electron beam exposure machine, a wafer carrier structure is designed to cooperate with the realization of high-precision positioning of the wafer clamp. Specifically, the two film feed guide rails 102 and the two self-locking slopes 103 are symmetrically arranged on both sides of the wafer carrier base plate, and the self-locking slopes 103 are trapezoidal in structure. The self-locking slopes 103 are arranged on the inner side of the film feed guide rail 102 and close to the limiting wall 105. Then, multiple first positioning bosses 104 are evenly distributed on the base plate 101 and are located on the inner side of the self-locking slopes 103. Limiting components are set on both sides of the limiting wall 105; correspondingly, a guide roller, a positioning roller 204 and a second positioning boss 205 are set on the fixture body 201 of the wafer clamp 200, the guide roller matches the film feed guide rail 102, the positioning roller 204 matches the self-locking slope 103, and the first positioning boss 104 matches the second positioning boss 205; when the guide roller belt In the process of the movable wafer clamp 200 moving from the film transfer port 108 along the film feed guide 102 toward the limit wall 105, the positioning roller drives the wafer clamp 200 to first rise and then fall along the self-locking slope 103. In the process of the wafer clamp 200 falling along the self-locking slope 103, the second positioning boss 205 stays on the first positioning boss 104. The positioning of the wafer in the X, Y and Rz directions is achieved by utilizing the limiting components on both sides of the limit wall 105. The positioning of the wafer in the Z, Rx and Ry directions is achieved by utilizing the cooperation between the first positioning boss 104 and the second positioning boss 205. This embodiment adopts a fixed position to achieve high repeatability positioning accuracy, without the need for additional electrical components, which is simpler for the equipment and has higher long-term reliability. Finally, high-precision positioning of the wafer in the Z, Rz, Rx and Ry degrees of freedom is achieved, meeting the special working environment requirements of the electron beam exposure machine.

[0043] like Figure 2 As shown, one side of the limiting wall 105 is a V-shaped boss with the pointed corner facing forward, and fixed reference columns 106 are installed on the inclined surfaces on both sides of the V-shaped boss. The other side of the limiting wall 105 is a rectangular boss, and an adjustable reference column 107 is provided on the end face of the rectangular boss facing the film transmission port 108.

[0044] In this embodiment, the fixed reference column 106 is inlaid with sapphire, and can also be made directly by processing. The requirement for the V-shaped boss is that its surface is 45° to the film transmission direction, and the two surfaces are symmetrical to the film transmission direction, thus forming a 90° V-shaped surface. The specific accuracy requirement value of the fixed reference column 106 can be determined according to the positioning accuracy requirement of the wafer. The adjustable reference column 107 can determine the boss height of the adjustable reference column by the screwing depth of the set screw at its rear. This design is to match the positioning position of the wafer clamp 200 with the V-shaped surface on the other side of the limiting wall 105 to maintain consistency. The design of fixed on one side and adjustable on the other side can greatly reduce the overall precision processing requirements for the limiting wall 105.

[0045] like Figure 3 As shown, one side of the end of the fixture body 201 is provided with a recessed V-shaped notch, with fixed bosses 206 mounted on the inclined surfaces on both sides of the V-shaped notch. The other side of the end of the fixture body 201 is provided with a recessed rectangular notch, with horizontal bosses 207 mounted on the rectangular notch. The fixed bosses 206 mate with the fixed reference posts 106, and the horizontal bosses 207 mate with the adjustable reference posts 107, to achieve wafer positioning in the X, Y, and Rz directions.

[0046] In this embodiment, fixed boss 206 is formed by inlaying sapphire, and its position is consistent with that of fixed reference post 106 on the V-shaped boss of limiting wall 105. This is also a key structural component for wafer positioning. Horizontal boss 207 is also inlaid with sapphire, but the height of this boss is not strictly required; it only needs to be perpendicular to the wafer transfer direction. The adjustable reference post 107 on the wafer carrier 100 can be adjusted in height to achieve a matching relationship.

[0047] In this embodiment, since the bottom guide roller 203 acts on the film feed guide rail 102, the surface of the film feed guide rail 102 is slightly higher than the surface of the wafer stage 100. Therefore, during the film transfer process, the three positioning rollers 204 passing through the self-locking slope 103 are suspended and inactive most of the time. However, when passing through the self-locking slope 103, since the trapezoidal upper surface is higher than the surface of the film feed guide rail 102, the wafer clamp 200 will be lifted a certain distance through the three positioning rollers 204 and the self-locking slope 103, and then begin to descend along the downhill slope. The bottom of the wafer clamp 200 is adjacent to the position of the three positioning rollers 204, and there are three second positioning bosses 205, which are made of inlaid sapphire glass. Through high processing precision and adjustment means, the surfaces of the three second positioning bosses 205 are ensured to be in the same plane, and their positions correspond one-to-one with the positions of the three first positioning bosses on the wafer carrier 100. Based on the three-point positioning principle, in order to ensure the accuracy of horizontality, the contact surfaces of the positioning bosses need to be in the same horizontal plane. Therefore, both sets of positioning bosses have high processing precision and adjustment precision requirements. When the wafer clamp 200 descends along the ramp of the self-locking slope 103, it will reach the positioning position halfway, that is, the second positioning boss 205 of the wafer clamp 200 will stop on the first positioning boss 104 of the wafer carrier 100, achieving the wafer positioning requirement for horizontality, that is, the repeatable positioning accuracy in the Z, Rx, and Ry directions. In addition, the positioning of the X, Y, and Rz directions by the structure of the limit wall described above, through the above structure and method, high-precision positioning of the wafer can be achieved without the help of components.

[0048] In this embodiment, the film feed guide rail 102 is in a right-angled shape, and the guide rollers include a lateral guide roller 202 and a bottom guide roller 203. The lateral guide roller 202 moves along the side of the film feed guide rail 102, and the bottom guide roller 203 moves along the bottom of the film feed guide rail 102 to avoid direct contact and friction.

[0049] like Figure 2 As shown, a mounting boss 301 is further provided on the base plate 101. The mounting boss 301 is located on the outside of the film feed guide rail 102. The mounting boss 301 is used to install and measure the long reflective mirror. The height and flatness of the mounting boss 301 are required to have high processing accuracy. The installation height and horizontality benchmark of the long reflective mirror are achieved by the mounting boss 301, which is also an important basis for realizing the measurement of the position of the film stage.

[0050] like Figure 2 As shown, a mounting groove 302 is further provided on the base plate 101. The mounting groove 302 is located in the middle of the base plate 101. The mounting groove 302 is used to accommodate and install a locking device to provide a locking force for the positioned wafer clamp 200 so that it can continue to remain in a positioned state.

[0051] like Figure 2 As shown, a mark mounting seat 303 is also provided on the base plate 101 for fixing the marked silicon wafer. After the mark position is detected by electron beam scanning, the mark position is used as the origin of the wafer stage in the control system for coordinate system conversion.

[0052] The wafer positioning device of this embodiment can achieve high repeatability positioning accuracy while having low requirements for processing accuracy. It only has high requirements for V-shaped structure processing, and the position matching with the V-shaped structure can be achieved through the adjustable reference column. Similarly, since structural parts are used to achieve repeatability positioning, it has better reliability than using electrical components. The working principle of the wafer positioning device of this embodiment is simple and reliable. It realizes a positioning scheme with a certain degree of self-locking effect by utilizing different heights. Positioning is achieved through a mechanical structure, and a fixed structural surface is used as a reference surface for positioning. In this way, it has a high repeatability positioning accuracy. It is equipped with an electrically controlled clamping device to press the wafer clamp 200 tightly against the reference surface, which is conducive to ensuring accuracy and greatly improves the reliability of positioning.

[0053] Example 2

[0054] like Figure 5 As shown, the wafer positioning device positioning method for an electron beam exposure machine of the present invention is implemented based on the wafer positioning device in Example 1, and includes the following steps:

[0055] Step S1 : Under the push of the wafer transfer robot, the side guide rollers 202 and the bottom guide rollers 203 drive the wafer clamp 200 to move forward along the wafer feed guide rail 102 .

[0056] Step S2: When the wafer clamp 200 moves to the position of the self-locking slope 103, the positioning roller 204 contacts the surface of the self-locking slope 103, and the wafer clamp 200 begins to rise along the upper ramp of the self-locking slope 103 and leaves the bearing surface of the wafer feed guide rail 102.

[0057] Step S3: After positioning roller 204 passes the highest plane of self-locking slope 103, wafer clamp 200 begins to move forward and downward along the downward slope of self-locking slope 103. Second positioning boss 205 rests on first positioning boss 104. At this point, fixed boss 206 maintains contact with fixed reference post 106, and horizontal boss 207 maintains contact with adjustable reference post 107. This up-and-down slope design allows for the wafer clamp to sink into place, reducing friction between the reference feature surfaces, significantly reducing surface wear, ensuring accuracy, and improving long-term reliability.

[0058] Step S4: Use the locking device on the base plate 101 to fix the wafer clamp 200 so that the wafer clamp 200 rests against the limiting wall 105 , and achieve high-precision repeated positioning through the position reference of the reference columns on both sides of the limiting wall 105 .

[0059] In step S1 of this embodiment, while the lateral guide rollers 202 and the bottom guide rollers 203 are moving along the film feed guide rail 102 , the positioning rollers 204 are in a suspended state.

[0060] Specifically, because the bottom guide rollers 203 act on the film feed rail 102, and the surface of the film feed rail 102 is slightly higher than the surface of the wafer stage 100, during the film transfer process, the three positioning rollers 204 passing through the self-locking slope 103 are mostly suspended and inactive. However, when passing the self-locking slope 103, because the trapezoidal upper surface of the self-locking slope 103 is higher than the surface of the film feed rail 102, the wafer clamp 200 is lifted a certain distance by the three positioning rollers 204 and the self-locking slope 103, and then begins to descend along the downward slope. When the wafer clamp 200 descends along the ramp of the self-locking slope 103, it will reach the positioning position halfway, that is, the second positioning boss 205 of the wafer clamp 200 will stay on the first positioning boss 104 of the wafer carrier 100, realizing the wafer positioning requirement for horizontality, that is, the repeatable positioning accuracy in the Z, Rx, and Ry directions, and the structure of the limiting wall 105 positions the wafer in the X, Y, and Rz directions, so that high-precision positioning of the wafer can be achieved without the aid of components.

[0061] In this embodiment, multiple sets of guide rollers are used to carry out the film transmission process before the positioning action, which improves the smoothness of the film transmission process and reduces the relative friction during the film transmission process. At the same time, the rolling of the guide wheels can keep the key components related to the uphill and downhill actions suspended during the film transmission process, avoiding the loss of the reference features and further strengthening the guarantee of positioning accuracy and long-term reliability.

[0062] Although the present invention is disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the spirit and technical solutions of the present invention, use the methods and technical contents disclosed above to make many possible changes and modifications to the technical solutions of the present invention, or modify them into equivalent embodiments with equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments based on the technical spirit of the present invention without departing from the content of the technical solutions of the present invention, shall still fall within the scope of protection of the technical solutions of the present invention.

Claims

1. A wafer positioning device for an electron beam exposure machine, characterized in that: The invention comprises a wafer carrier (100) and a wafer clamp (200); the wafer carrier (100) comprises a bottom plate (101), and a wafer feed guide rail (102), a self-locking slope (103), a first positioning boss (104), a limiting wall (105) and a wafer transfer port (108) arranged on the bottom plate (101); the two wafer feed guide rails (102) and the two self-locking slopes (103) are symmetrically arranged on both sides of the bottom plate (101); the self-locking slopes (103) are in a trapezoidal structure, and the self-locking slopes (103) are arranged on the bottom plate (101). (103) is located on the inner side of the film feed guide rail (102) and close to the limiting wall (105), a plurality of the first positioning bosses (104) are evenly distributed on the bottom plate (101) and are located on the inner side of the self-locking slope (103), the limiting wall (105) and the film transfer port (108) are relatively arranged at the two ends of the bottom plate (101), and limiting components are provided on both sides of the limiting wall (105) to realize the positioning of the wafer clamp (200) carrying the wafer in the X, Y and Rz directions; the wafer clamp (20 0) includes a clamp body (201), the clamp body (201) is provided with a guide roller, a positioning roller (204) and a second positioning boss (205), the guide roller matches the wafer feed guide rail (102) and is used to assist the wafer clamp (200) in carrying the wafer in and out of the wafer carrier (100), the positioning roller (204) matches the self-locking slope (103), and the first positioning boss (104) matches the second positioning boss (205); when the guide roller drives the wafer clamp During the process of the wafer clamp (200) moving from the wafer conveying port (108) along the wafer feeding guide rail (102) toward the limiting wall (105), the positioning roller (204) drives the wafer clamp (200) to first rise and then fall along the self-locking slope (103); during the process of the wafer clamp (200) falling along the self-locking slope (103), the second positioning boss (205) stays on the first positioning boss (104) to realize the positioning of the wafer clamp (200) carrying the wafer in the Z, Rx and Ry directions.

2. The wafer positioning device for an electron beam exposure machine according to claim 1, wherein: One side of the limiting wall (105) is a V-shaped boss with its pointed corner facing forward, and fixed reference columns (106) are installed on the inclined surfaces on both sides of the V-shaped boss. The other side of the limiting wall (105) is a rectangular boss, and an adjustable reference column (107) is provided on the end surface of the rectangular boss facing the film transmission port (108).

3. The wafer positioning device for an electron beam exposure machine according to claim 2, wherein: A concave V-shaped notch is provided on one side of the end of the clamp body (201), and fixed bosses (206) are installed on the inclined surfaces on both sides of the V-shaped notch. A concave rectangular notch is provided on the other side of the end of the clamp body (201), and a horizontal boss (207) is installed on the rectangular notch; the fixed boss (206) matches the fixed reference column (106), and the horizontal boss (207) matches the adjustable reference column (107), so as to realize the positioning of the wafer in the X, Y and Rz directions.

4. The wafer positioning device for an electron beam exposure machine according to claim 3, wherein: The film feed guide rail (102) is in a right-angled shape, and the guide rollers include lateral guide rollers (202) and bottom guide rollers (203). The lateral guide rollers (202) move along the sides of the film feed guide rail (102), and the bottom guide rollers (203) move along the bottom of the film feed guide rail (102).

5. The wafer positioning device for an electron beam exposure machine according to any one of claims 1 to 4, characterized in that: The bottom plate (101) is further provided with a mounting boss (301), the mounting boss (301) being located outside the film feed guide rail (102), and the mounting boss (301) is used for mounting a reflector.

6. The wafer positioning device for an electron beam exposure machine according to any one of claims 1 to 4, characterized in that: The base plate (101) is further provided with a mounting groove (302), which is located in the middle of the base plate (101). The mounting groove (302) is used to accommodate and install a locking device to provide a locking force for the wafer clamp (200) after positioning.

7. The wafer positioning device for an electron beam exposure machine according to any one of claims 1 to 4, characterized in that: The bottom plate (101) is also provided with a marking mounting seat (303) for fixing the marking silicon wafer.

8. The wafer positioning device for an electron beam exposure machine according to any one of claims 1 to 4, characterized in that: Three of the first positioning bosses (104) and the second positioning bosses (205) are provided to achieve three-point determination of the plane.

9. A positioning method for a wafer positioning device for an electron beam exposure machine based on any one of claims 1 to 8, characterized in that: The following steps are included: Step S1: Under the push of the wafer conveyor robot, the side guide rollers (202) and the bottom guide rollers (203) drive the wafer clamp (200) to move forward along the wafer feed guide rail (102); Step S2: When the wafer clamp (200) moves to the position of the self-locking slope (103), the positioning roller (204) contacts the surface of the self-locking slope (103), and the wafer clamp (200) begins to rise along the upper ramp of the self-locking slope (103) and leaves the bearing surface of the wafer feed guide rail (102); Step S3, after the positioning roller (204) passes the highest plane of the self-locking slope (103), the wafer clamp (200) starts to move forward and downward along the downhill slope of the self-locking slope (103), and the second positioning boss (205) stops on the first positioning boss (104). At this time, the fixed boss (206) and the fixed reference column (106), and the horizontal boss (207) and the adjustable reference column (107) are in contact. Step S4: Using the locking device on the base plate (101) to fix the wafer clamp (200), the wafer clamp (200) is placed against the limiting wall (105), and high-precision repeated positioning is achieved through the position reference of the reference columns on both sides of the limiting wall (105).

10. The positioning method according to claim 9, characterized in that: In step S1, while the lateral guide roller (202) and the bottom guide roller (203) are moving along the film feed guide rail (102), the positioning roller (204) is in a suspended state.

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