A pre-alignment device and alignment method

Abstract

This invention relates to the field of semiconductor processing technology, and discloses a pre-alignment device and alignment method. The device includes a stage with an elongated hole extending along a first direction; a support assembly comprising a first support pillar and a support component, the support component including two second support pillars distributed along a second direction on both sides of the elongated hole, the first support pillar and the two second support pillars supporting a wafer; an adjustment assembly comprising a tray and a drive component, the drive component located below the stage, the drive component having an output shaft passing through the elongated hole and connected to the tray, the tray carrying and holding the wafer, the drive component driving the tray to move; and a detection device disposed above the alignment device, the detection device comprising a housing and a camera, the camera being mounted inside the housing, the bottom wall of the housing having a clearance hole, the camera being able to illuminate the edge of the wafer near the first support pillar through the clearance hole.

Description

Technical Field

[0001] This invention relates to the field of semiconductor processing technology, and in particular to a pre-alignment device and alignment method. Background Technology

[0002] Currently, most pre-aligners on the market connect the main body and camera unit via a support shaft, forming a C-shaped structure. The wafer is pre-aligned in the center. Due to the presence of the support shaft, the distance between the camera and the main body is relatively fixed. This traditional pre-aligner structure becomes limiting when space requirements are large or when unobstructed access in all four directions is needed. Furthermore, existing pre-aligners use a robotic arm for position compensation after identifying wafer centering deviations, and then use the robotic arm to pick up the wafer. However, adding a robotic arm increases product size, hinders spatial layout, and raises equipment costs.

[0003] Therefore, there is an urgent need for a pre-alignment instrument and alignment method to solve the aforementioned problems. Summary of the Invention

[0004] Based on the above, the purpose of this invention is to provide a pre-alignment instrument and alignment method, in which there are no connecting rods between the alignment device and the detection device, and no obstruction in the four horizontal directions; the pre-alignment of the wafer can be achieved by using an adjustment component, eliminating the need for a robotic arm, reducing product size, facilitating space layout, and lowering equipment costs.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] On one hand, a pre-alignment device is provided, including an alignment device and a detection device, wherein the alignment device includes:

[0007] A platform, wherein an elongated hole extending in a first direction is provided on the platform;

[0008] A support assembly, comprising a first support post and a support component, the support component comprising at least two second support posts, the second support posts being distributed along a second direction on both sides of the elongated hole, the first support post and the at least two second support posts being used to support the wafer;

[0009] An adjustment assembly includes a tray and a drive component. The drive component is located below the stage and has an output shaft that passes through the elongated hole and is connected to the tray. The tray is used to carry and hold wafers, and the drive component is used to drive the tray to move.

[0010] The detection device is disposed above the alignment device. The detection device includes a housing and a camera. The camera is installed inside the housing. The bottom wall of the housing is provided with a clearance hole. The camera can illuminate the edge of the wafer near the first support pillar through the clearance hole.

[0011] As a preferred technical solution for a pre-alignment device, the support components are at least two sets, and each set of the support components includes two second support columns; the support components are spaced apart along the first direction, and the distance between the two second support columns in the support components gradually increases in the direction away from the first support column.

[0012] As a preferred technical solution for a pre-alignment device, the two second support columns in the support component are disposed on the upper surface of the stage and are symmetrically arranged around the center line of the elongated hole; the first support column is disposed near one end of the elongated hole, and the two second support columns in the same group are arranged in an isosceles triangle with the first support column.

[0013] As a preferred technical solution for a pre-alignment device, the support end faces of the first support column and the second support column are on the same horizontal plane.

[0014] As a preferred technical solution for a pre-alignment device, a height adjustment device is provided below the first support column and / or the second support column. The height adjustment device is adapted to adjust the height of the support end faces of the first support column and the preset second support column to the same horizontal height.

[0015] As a preferred technical solution for a pre-alignment device, the support end faces of the two second support columns in each set of support components are located on the same horizontal plane, and the height of the second support column gradually increases in the direction away from the first support column;

[0016] The support assembly further includes a second lifting drive, which is connected to the first support column and drives the first support column to rise and fall to be flush with the support end face of the second support column in one of the support components, so as to horizontally support one of the wafers.

[0017] As a preferred technical solution for a pre-alignment device, the driving component includes a first horizontal driving member, a first lifting driving member, and a first rotary driving member. The first horizontal driving member is driven and connected to the first lifting driving member, and the first horizontal driving member is used to drive the first lifting driving member to move along a first direction. The first lifting driving member is driven and connected to the first rotary driving member, and the first lifting driving member is used to drive the first rotary driving member to move up and down. The first rotary driving member is provided with an output shaft, which passes through the elongated hole and is connected to the tray. The first rotary driving member is used to drive the tray to rotate.

[0018] As a preferred technical solution for a pre-alignment device, the detection device further includes a buffer assembly, which is installed at the bottom of the housing and spaced apart from the camera along a first direction. The buffer assembly includes a non-contact suction cup for adsorbing the wafer.

[0019] As a preferred technical solution for a pre-alignment device, the buffer assembly further includes a third lifting drive, a mounting base plate, a mounting plate, and multiple positioning pins. The third lifting drive is connected to the housing and driven to the mounting base plate. The third lifting drive is used to drive the mounting base plate to lift. The mounting plate and the non-contact suction cup are both mounted on the mounting base plate.

[0020] Multiple positioning pins are disposed on the mounting plate, and multiple positioning pins are arranged around the non-contact suction cup. The wafer can be embedded between multiple positioning pins.

[0021] As a preferred technical solution for a pre-alignment device, the non-contact chuck is a Bernoulli chuck or an electrostatic chuck.

[0022] As a preferred technical solution for a pre-alignment device, the end of the positioning pin away from the mounting plate is provided with a tapered portion, and the sidewalls of the plurality of positioning pins near the non-contact chuck form a first circle, the centers of the tapered portions of the plurality of positioning pins form a second circle, and the diameter of the wafer is between the diameter of the first circle and the diameter of the second circle.

[0023] On the other hand, an alignment method is provided for use with any of the pre-aligners described above, the alignment method comprising the following steps;

[0024] S1. Place the wafer horizontally on the first support pillar and the two second support pillars;

[0025] S2. The driving component drives the tray to move below the wafer, lifts the wafer and drives the wafer to rotate by a preset angle. When the wafer rotates, the camera acquires the contour information of the wafer edge and calculates the center coordinates of the wafer. The eccentricity of the wafer is calculated based on the center coordinates.

[0026] S3. The driving component drives the wafer to rotate according to the eccentricity data calculated in step S2, so that the line connecting the center of the wafer and the center of the tray is located in the first direction.

[0027] S4. After the driving component drives the tray to descend to a horizontal height lower than the first support column, the wafer is supported by the first support column and one of the second support columns. Then the tray moves along the first direction to directly below the wafer, and the center of the wafer and the center of the tray are on the same vertical line.

[0028] S5. The driving component drives the tray to move upward and lifts the wafer, completing the center calibration of the wafer.

[0029] As a preferred embodiment of the alignment method, when the edge of the wafer is provided with a notch or a flat edge, step S2 further includes the camera acquiring the coordinates of the notch or flat edge;

[0030] The alignment method further includes:

[0031] S6. The driving component drives the tray to rotate so that the line connecting the center of the notch or the center of the flat edge with the center of the tray is located in the first direction.

[0032] The beneficial effects of this invention are as follows:

[0033] This invention provides a pre-alignment device. During operation, the edge of a wafer is attached to a first support pillar and two second support pillars. A driving component moves a tray below the wafer, lifts the wafer, and drives it to rotate by a preset angle. As the wafer rotates, a camera acquires the wafer's contour information and calculates the wafer's center coordinates. Based on these coordinates, a center offset is calculated. The driving component drives the wafer so that its center is located on one side of the tray's center along a first direction. The driving component then drives the tray to descend and move along the first direction so that the tray's center coincides with the wafer's center. Finally, the driving component lifts the wafer with the tray, completing the wafer alignment.

[0034] This invention separates the alignment device and the detection device into two relatively independent modules. The alignment device and the detection device are installed independently, with no connecting rods between them and no obstructions in any of the four horizontal directions. Furthermore, after identifying the wafer's center deviation, the wafer pre-alignment can be achieved using an adjustment component, eliminating the need for a robotic arm, reducing product size, facilitating space layout, and lowering equipment costs. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of the pre-alignment device provided in a specific embodiment of the present invention;

[0037] Figure 2 This is a top view of the alignment device provided in a specific embodiment of the present invention;

[0038] Figure 3 This is a cross-sectional view of the detection device provided in a specific embodiment of the present invention;

[0039] Figure 4 This is a bottom view of the detection device provided in a specific embodiment of the present invention;

[0040] Figure 5 This is one of the cross-sectional views of the alignment device provided in a specific embodiment of the present invention;

[0041] Figure 6 This is a second cross-sectional view of the alignment device provided in a specific embodiment of the present invention;

[0042] Figure 7 This is a partial structural schematic diagram of the detection device provided in a specific embodiment of the present invention;

[0043] Figure 8 This is a flowchart of the alignment method provided in a specific embodiment of the present invention.

[0044] The markings in the image are as follows:

[0045] 1. Alignment device; 11. Housing; 111. Platform; 1111. Elongated hole; 12. Support assembly; 121. First support column; 122. Support component; 1221. Second support column; 123. Second lifting drive component; 13. Adjustment assembly; 131. Tray; 132. Drive component; 1321. First horizontal drive component; 1322. First lifting drive component; 1323. First rotation drive component; 13231. Output shaft;

[0046] 2. Detection device; 21. Housing; 211. Clearance hole; 22. Camera; 23. Buffer assembly; 231. Non-contact suction cup; 232. Third lifting drive component; 233. Mounting base plate; 234. Mounting plate; 235. Positioning pin; 2351. Conical part. Detailed Implementation

[0047] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0048] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0049] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0050] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0051] like Figures 1-4As shown, this embodiment provides a pre-alignment device, which includes an alignment device 1 and a detection device 2. The alignment device 1 includes a stage 111, a support assembly 12 and an adjustment assembly 13. The stage 111 is provided with an elongated hole 1111 extending along a first direction; the support assembly 12 includes a first support column 121 and a support component 122. The support component 122 includes at least two second support columns 1221. The at least two second support columns 1221 cooperate with one first support column 121 to achieve three-point support, which not only has good support stability, but also facilitates adjustment of the support level and effectively reduces the wear of the wafer on the support end face of the support column; the second support columns 1221 are distributed on both sides of the elongated hole 1111 along a second direction and are fixedly installed on the upper surface of the stage 111. In this embodiment, the second direction is perpendicular to the first direction on the horizontal plane. The two second support columns 1221 are symmetrically arranged on both sides of the elongated hole 1111. The first support column 121 and the two second support columns 1221 are used to support the position of the wafer near the edge, so that sufficient space is reserved between the support columns for the movement of the tray 131; adjustment assembly 1 The 3 includes a tray 131 and a driving component 132. The driving component 132 is located below the stage 111 and is provided with an output shaft 13231. The output shaft 13231 passes through the elongated hole 1111 and is connected to the tray 131. The tray 131 is used to carry and adsorb wafers. The driving component 132 is used to drive the tray 131 to lift, rotate and move along a first direction. The detection device 2 is located above the alignment device 1. The detection device 2 includes a housing 21 and a camera 22. In this embodiment, the camera 22 is preferably a linear array matrix camera. The side of the first support column 121 away from the elongated hole 1111 is basically located at the center of the scanning area of ​​the linear array camera. When wafers of different sizes are placed on the support component 12, the edge of the wafer located on the side of the first support column 121 is basically located at the center of the scanning area so that when the wafer rotates, the outline of its edge can pass through the scanning area and be acquired by the linear camera 22. Camera 22 is mounted inside housing 21. The bottom wall of housing 21 has a clearance hole 211, through which camera 22 can illuminate the edge of the wafer located on the first support post 121. In this embodiment, tray 131 can adsorb the wafer when holding it; the adsorption method is vacuum adsorption. Several vacuum nozzles or vacuum grooves can be provided on the support surface of tray 131 for vacuum adsorption, improving the stability of the wafer. See also... Figure 1 The first direction is X, the second direction is Y, and the first direction is perpendicular to the second direction.

[0052] During operation, the wafer is placed on the first support post 121 and the second support post 1221. (See also...) Figure 2 As shown, in this embodiment, a first support column 121 is provided, located outside the first elongated hole 1111 and near the end of the elongated hole 1111. Figure 2 On the horizontal projection plane shown, the line connecting the axis of the first support column 121 and the axis of the tray 131 is in the first direction (X direction), while the second support columns 1221 are symmetrically arranged on both sides of the elongated hole 1111 along the second direction (Y direction). The driving component 132 drives the tray 131 to move under the wafer, lifts the wafer, and drives the wafer to rotate at a preset angle. In this embodiment, the preset angle is preferably one full turn. When the wafer rotates, the edges of the wafer pass through the scanning area of ​​the camera 22 in sequence according to the direction of rotation. Figure 2 The elongated hole 1111 shown above acquires the wafer's outline information and calculates the wafer's center coordinates on the left side. Based on these coordinates, the center offset is calculated. The driving component 132 drives the wafer so that its center is located on one side of the center of the tray 131 along the first direction. At this point, the wafer's center offset in the Y direction is adjusted to 0, thus completing the Y-direction eccentricity correction. Then, the driving component 132 drives the tray 131 to descend to a height below the support end face of the support pillars. At this point, the wafer is separated from the tray 131 because it is supported by the first support pillar 121 and the second support pillar 1221. Once the tray 131 has completely separated from the wafer after moving downwards... The driving component 132 drives the tray 131 to move along the first direction until the center of the tray 131 is directly below the center of the wafer. At this time, the center of the tray 131 coincides with the horizontal projection of the center of the wafer, and the X-axis offset correction of the wafer is completed. Then, the driving component 132 drives the tray 131 to move upward and lifts the wafer placed on the first support column 121 and the second support column 1221 upward. After the wafer is separated from the support column, the tray 131 starts vacuum adsorption to fix the wafer. At this time, the center calibration of the wafer is completed. That is, at this time, the center of the wafer lifted on the tray 131 coincides with the center of the tray 131 itself. To facilitate photolithography alignment, existing wafers generally have notch marks and flat edge marks on their edges. In the above process, after the wafer rotates one revolution, the camera 22 collects the position information of the wafer edge, calculates not only the eccentricity of the wafer center, but also confirms the position coordinate information of the notch or flat edge mark at the wafer edge. When the center of the wafer is aligned with the center of the tray 131, the position information of the notch or flat edge of the wafer edge has been confirmed. By rotating a certain angle in the forward or reverse direction, the center point of the notch or flat edge of the wafer is rotated to a preset position to complete the edge finding action. Preferably, the line connecting the preset position of the notch or flat edge and the center of the tray 131 is in the first direction.

[0053] In this embodiment, the alignment device 1 and the detection device 2 are separated into two relatively independent modules. The alignment device 1 and the detection device 2 are installed independently, with no connecting rods between them, and no obstruction in the circumferential area between them. Furthermore, after identifying the wafer's center deviation, the wafer pre-alignment can be achieved using the adjustment component 13, eliminating the need for a robotic arm for position compensation, reducing product size, facilitating space layout, and lowering equipment costs. Finally, the wafer is supported by a first support pillar 121 and two second support pillars 1221, with their top surfaces flush to ensure the wafer remains flat during adsorption by the tray 131. This prevents the wafer from bending or breaking due to uneven force. The support provided by the first support pillar 121 and the two second support pillars 1221 offers good adsorption reliability and versatility, applicable to the support and adsorption of wafers of different sizes, offering high flexibility, easy maintenance, and low cost.

[0054] It should be noted that the camera 22 acquires the outline information of the wafer and calculates the center coordinates of the wafer when the wafer rotates. This is existing technology, and its working principle and calculation method will not be described in detail here.

[0055] Preferably, such as Figure 1 and Figure 2 As shown, there are at least two sets of support components 122. In this embodiment, seven sets are provided. Two second support pillars 1221 within each set of support components 122 are symmetrically arranged relative to the elongated hole 1111. Each set of support components 122 includes two second support pillars 1221. The support components 122 in each set are spaced apart along a first direction, and the distance between the two second support pillars 1221 in each support component 122 gradually increases in the direction away from the first support pillar 121 to accommodate wafers with larger dimensions. By providing multiple sets of support components 122, it is convenient for the support components 122 and the first support pillars 121 to cooperate in supporting wafers of different sizes. In other embodiments, each set of support components 122 may also include three or more second support pillars 1221, or even be configured with two or more staggered support points at the upper end of one second support pillar 1221 for support. The specific support form is not limited, as long as it can cooperate with the first support pillar 121 to achieve multi-point support for the wafer.

[0056] In existing technologies, wafers of different sizes are concentric during pre-alignment. This results in inconsistent scanning positions for the camera during pre-alignment. Designing a separate camera for each wafer size offers the advantage of fixed camera positions and ease of use. However, this approach significantly increases cost and space requirements due to the use of multiple cameras. Another approach involves adding a transverse axis to the camera, moving its position so that the pre-aligner's camera can precisely scan the edges of wafers of different sizes. However, this approach requires an additional motion axis to drive the camera movement, and this axis has high requirements for load and motion accuracy. Furthermore, depending on the required wafer size, the travel of this motion axis can reach nearly 150mm when compatible with 2-12 inch wafers. Therefore, it also significantly impacts overall space and price. Moreover, camera movement not only affects its optimal focal plane (affecting image acquisition clarity), but frequent movements also increase computational load and accumulated errors due to frequent changes in the camera's reference coordinates, thus significantly impacting detection accuracy.

[0057] To solve the above problems, such as Figure 2 and Figure 5 As shown, this application provides a base point on the side of the first support post 121 away from the elongated hole 1111 (this base point is preset by the system and is not specifically set in the pre-alignment instrument). Wafers of different sizes and models are placed starting from this base point. See [link to relevant documentation]. Figure 2As the wafer size increases, the right edge of the wafer gradually extends to the right. When the height of the second support pillar 1221 in each group is the same as that of the first support pillar 121, the second support pillar 1221 under the horizontal projection of the wafer of the corresponding size will all play a supporting role. The advantage of this method is that it can provide multi-point support for the bottom surface of the wafer. The disadvantage is that when multiple second support pillars 1221 are adjusted to the same horizontal height, the assembly process requirements are high, and if the wafer is not flat enough, it will also affect the stability of the support. Therefore, in other embodiments, the support end faces of the two second support columns 1221 in each set of support components 122 are located on the same horizontal plane, and the height of the second support columns 1221 in adjacent support components 122 gradually increases in the direction away from the first support column 121; for example, the increased height can be about 1-2 mm, and the height difference can also be other values; the support assembly 12 also includes a second lifting drive 123, which is connected to the first support column 121 and drives the first support column 121 to rise and fall to be flush with the support end face of the second support column 1221 in one of the sets of support components 122, so as to horizontally support a wafer. In this embodiment, different groups of support components 122 correspond to different types of wafers. Therefore, when supporting wafers of different types, the second lifting drive component 123 drives the first support column 121 to rise and fall, so that the first support column 121 and the second support column 1221 of the corresponding support component 122 are at the same height. This ensures that the edges of wafers of different types are supported by one first support column 121 and two second support columns 1221, which is a three-point support. For the horizontal adjustment process, since the number of support points is small, it is easier to adjust the level. Moreover, since the three-point support reduces the contact area with the back of the wafer, it can reduce wear on the back of the wafer. Furthermore, in this embodiment, when wafers of different types are placed on the first support column 121, the edge of the wafer on the side closest to the first support column 121 is located at the base point and is within the detection range of the camera 22. When the wafer rotates, the edge of the wafer below the camera 22 is always within the detection range of the camera 22, so that the pre-alignment requirements of wafers of different specifications can be met using only one camera 22.

[0058] Preferably, the first support post 121 and the second support post 1221 can adsorb wafers, improving the stability of the wafer support. The second support posts 1221 of different sets of support components 122 can operate independently with vacuum switches to achieve the purpose of adsorbing wafers of different sizes.

[0059] like Figure 2As shown, this embodiment includes a total of 7 sets of support components 122. Along the direction away from the first support column 121, the first set of support components 122, in conjunction with the first support column 121, can support a 2-inch wafer; the second set of support components 122, in conjunction with the first support column 121, can support a 3-inch wafer; the third set of support components 122, in conjunction with the first support column 121, can support a 4-inch wafer; the fourth set of support components 122, in conjunction with the first support column 121, can support a 5-inch wafer; the fifth set of support components 122, in conjunction with the first support column 121, can support a 6-inch wafer; the sixth set of support components 122, in conjunction with the first support column 121, can support an 8-inch wafer; and the seventh set of support components 122, in conjunction with the first support column 121, can support a 12-inch wafer. Figure 2 The seven circles shown represent the outlines of 2-inch, 3-inch, 4-inch, 5-inch, 6-inch, 8-inch, and 12-inch wafers (these are also the most common standard wafer sizes). Wafers of different models are not pre-aligned simultaneously on the pre-aligner of this invention. Instead, each batch of pre-alignment is performed only for one type of wafer. For example, when pre-aligning a 2-inch wafer, only one type of wafer is used. Figure 2 The leftmost three support pillars provide support, while when pre-aligning a 12-inch wafer, the 12-inch wafer is mainly supported by the leftmost first support pillar 121 and the rightmost two second support pillars 1221.

[0060] When supporting wafers of different sizes, it is preferable that the two second support pillars 1221 closest to the wafer edge in the horizontal projection of the wafer work in conjunction with the first support pillar 121. Of course, if the height of all the second support pillars 1221 on the stage 111 is set to the same level, and the supporting end faces of the first and second support pillars 121 are on the same horizontal plane, then all the second support pillars 1221 and the first support pillar 121 in the horizontal projection of the corresponding size wafer will provide support for that wafer. Taking a 12-inch wafer as an example, in this case… Figure 2 The first support pillar 121 and the second support pillar 1221 shown are both located below the horizontal projection of the 12-inch wafer, and together they support the 12-inch wafer, as shown. Figure 6 As shown, the second support columns 1221 of the multiple sets of support components 122 have the same height, which simplifies the product structure. During assembly, the horizontal height of each second support column 1221 needs to be adjusted to be consistent, and each second support column 1221 can be fixed to the upper surface of the platform 111.

[0061] In other embodiments, a height adjustment device is provided below the first support column 121 and / or the second support column 1221. The height adjustment device is adapted to adjust the height of the support end faces of the first support column 121 and the preset second support column 1221 to the same horizontal level. That is, the height of the first support column 121 and the second support column 1221 in this application can be adjusted by the height adjustment device, or the height of one of them can be fixed, and the height of the other can be adjusted by the height adjustment device. The above embodiments describe the height adjustment of the first support column 121. In other embodiments, the first support column 121 can be fixed, and a height adjustment device can be provided below the second support column 1221. A separate height adjustment device can be provided below each second support column 1221, or all the second support columns 1221 with height differences can be adjusted as a whole. This application does not limit this, as long as it is convenient to adjust the support effect of the support column on the wafer; and the structure of the height adjustment device is not limited, as long as it is a mechanism or device that is easy to control and can be driven up and down.

[0062] Further, the driving component 132 includes a first horizontal driving member 1321, a first lifting driving member 1322, and a first rotary driving member 1323. The first horizontal driving member 1321 is driven and connected to the first lifting driving member 1322, and is used to drive the first lifting driving member 1322 to move along a first direction. The first lifting driving member 1322 is driven and connected to the first rotary driving member 1323, and is used to drive the first rotary driving member 1323 to lift and lower. The first rotary driving member 1323 is provided with an output shaft 13231, which passes through an elongated hole 1111 and is connected to the tray 131. The first rotary driving member 1323 is used to drive the tray 131 to rotate. When the first horizontal driving member 1321 drives the first lifting driving member 1322 to move along the first direction, it further drives the tray 131 to move along the first direction. When the first lifting driving member 1322 drives the first rotary driving member 1323 to lift and lower, it further drives the tray 131 to lift and lower. In this embodiment, both the first horizontal drive component 1321 and the first lifting drive component 1322 are linear drive modules, and the first rotary drive component 1323 is a rotary motor. In this embodiment, the drive component 132 is disposed inside the housing 11, and a platform 111 is disposed on the top of the housing 11.

[0063] Preferably, such as Figure 3 , Figure 4 and Figure 7As shown, the detection device 2 also includes a buffer assembly 23, which is installed at the bottom of the housing 21. The buffer assembly 23 and the camera 22 are spaced apart along a first direction. The buffer assembly 23 includes a non-contact chuck 231, which is used to adsorb the wafer. When the wafer needs to be buffered, the non-contact chuck 231 adsorbs the top surface of the wafer, thus achieving wafer buffering. The non-contact chuck 231 does not contact the top surface of the wafer, preventing contamination or damage to the coated surface of the wafer. The non-contact chuck 231 is a Bernoulli chuck or an electrostatic chuck. In this embodiment, the non-contact chuck 231 is a Bernoulli chuck. The buffer assembly 23 adds a buffer station for temporarily storing or transferring the photolithographically completed wafer.

[0064] More preferably, the cache component 23 further includes a third lifting drive 232, a mounting base plate 233, a mounting plate 234, and a plurality of positioning pins 235. The third lifting drive 232 is connected to the housing 21 and driven to the mounting base plate 233. The third lifting drive 232 is used to drive the mounting base plate 233 to lift. The mounting plate 234 and the non-contact suction cup 231 are both mounted on the mounting base plate 233. The plurality of positioning pins 235 are disposed on the mounting plate 234 and are arranged around the non-contact suction cup 231. The wafer can be embedded between the plurality of positioning pins 235.

[0065] The third lifting drive 232 drives the mounting base plate 233 to move up and down, which in turn drives the mounting plate 234 and the non-contact suction cup 231 to move up and down together. When it is necessary to adsorb the wafer, the fork arm transports the wafer to directly below the Bernoulli suction cup. The third lifting drive 232 pushes the Bernoulli suction cup downward to a preset distance. At this time, the gap between the upper surface of the wafer and the Bernoulli suction cup is within the adsorption range of the suction cup. The Bernoulli suction cup activates positive pressure, and the wafer is adsorbed from above by Bernoulli principle. The wafer is embedded between multiple positioning pins 235, which restrict the wafer from moving or flipping radially.

[0066] In this embodiment, the third lifting drive component 232 can be an electric cylinder, a pneumatic cylinder, or a hydraulic cylinder. In this embodiment, an electric cylinder is selected. The motor of the electric cylinder is fixed inside the housing 21 by a motor mounting bracket. The end of the output shaft 13231 of the electric cylinder is connected to and coaxially arranged with the Bernoulli suction cup. The electric cylinder drives the Bernoulli suction cup to complete the ejection or resetting action.

[0067] Preferably, the end of the positioning pin 235 away from the mounting plate 234 is provided with a tapered portion 2351. Multiple positioning pins 235 form a first circle near the sidewall of the non-contact suction cup 231, and the centers of the tapered portions 2351 of the multiple positioning pins 235 form a second circle. The diameter of the wafer is between the diameters of the first and second circles. After the non-contact suction cup 231 adsorbs the wafer, the edge of the wafer abuts against the tapered portion 2351 of the positioning pin 235, thereby fixing the wafer position and preventing horizontal sliding. The friction between the wafer and the tapered portion 2351 restricts wafer rotation. Preferably, there are three positioning pins 235. Of course, in other embodiments, four, five, six, etc., can also be used. Regardless of the number of positioning pins 235, the tapered portions 2351 of each positioning pin 235 have the same structure and are evenly spaced along the circumferential direction.

[0068] More preferably, the mounting plate 234 is detachably connected to the mounting base plate 233, facilitating replacement of the mounting plate 234 as needed. Different locating pins 235 are required for wafers of different sizes; therefore, mounting plates 234 of different sizes are provided for replacement, ensuring the correct mounting plate 234 is used.

[0069] like Figure 8 As shown, this embodiment also provides an alignment method applied to the pre-aligner described above. The alignment method includes the following steps;

[0070] S1. Place the wafer horizontally on the first support post 121 and two second support posts 1221; wherein the edge of the wafer on the first support post 121 is within the detection range of the camera 22.

[0071] S2. The driving component 132 drives the tray 131 to move below the wafer, lifts the wafer, and drives the wafer to rotate by a preset angle. When the wafer rotates, the camera 22 acquires the contour information of the wafer edge and calculates the center coordinates of the wafer. Based on the center coordinates, the eccentricity of the wafer is calculated. The position of the tray 131 lifting the wafer is approximately located at the center of the wafer, so that when the wafer rotates by the preset angle, the edge of the wafer located below the camera 22 is always within the detection range of the camera 22.

[0072] S3. The drive component 132 drives the wafer to rotate according to the eccentricity data calculated in step S2, so that the line connecting the center of the wafer and the center of the tray 131 is located in the first direction; ensuring that the center of the wafer is located on the moving path of the tray 131 along the first direction.

[0073] S4. After the drive component 132 drives the tray 131 to descend to a horizontal height lower than the first support column 121, the wafer is supported by the first support column 121 and one of the second support columns 1221. Then the tray 131 moves along the first direction to directly below the wafer, and the center of the wafer and the center of the tray 131 are on the same vertical line to compensate for the center eccentricity.

[0074] S5, the driving component 132 drives the tray 131 to move upward and lift the wafer, completing the center calibration of the wafer.

[0075] Furthermore, when the edge of the wafer is provided with a notch or a flat edge, step S2 also includes camera 22 acquiring the coordinates of the notch or flat edge; the alignment method also includes: S6, drive component 132 drives tray 131 to rotate so that the line connecting the center of the notch or the center of the flat edge and the center of tray 131 is located in a first direction, thus completing the orientation.

[0076] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A pre-alignment device, characterized in that, It includes an alignment device (1) and a detection device (2), wherein the alignment device (1) includes: A platform (111) is provided with an elongated hole (1111) extending in a first direction. The support assembly (12) includes a first support post (121) and a support component (122). The support component (122) includes at least two second support posts (1221). The second support posts (1221) are distributed along a second direction on both sides of the elongated hole (1111). The first support post (121) and the at least two second support posts (1221) are used to support the wafer. The adjustment component (13) includes a tray (131) and a drive component (132). The drive component (132) is located below the stage (111). The drive component (132) is provided with an output shaft (13231). The output shaft (13231) passes through the elongated hole (1111) and is connected to the tray (131). The tray (131) is used to carry and adsorb wafers. The drive component (132) is used to drive the tray (131) to move. The detection device (2) is disposed above the alignment device (1). The detection device (2) includes a housing (21) and a camera (22). The camera (22) is installed inside the housing (21). The bottom wall of the housing (21) is provided with a clearance hole (211). The camera (22) can illuminate the edge of the wafer near the first support post (121) through the clearance hole (211). The support member (122) is at least two sets, and each set of the support member (122) includes two second support columns (1221); the support members (122) are spaced apart along the first direction, and the distance between the two second support columns (1221) in the support member (122) gradually increases in the direction away from the first support column (121).

2. The pre-alignment device according to claim 1, characterized in that, The two second support columns (1221) in the support component (122) are disposed on the upper surface of the platform (111) and are symmetrically arranged with respect to the center line of the elongated hole (1111); the first support column (121) is disposed near one end of the elongated hole (1111), and the two second support columns (1221) in the same group are arranged in an isosceles triangle with the first support column (121).

3. The pre-alignment device according to claim 2, characterized in that, The support end faces of the first support column (121) and the second support column (1221) are on the same horizontal plane.

4. The pre-alignment device according to claim 2, characterized in that, A height adjustment device is provided below the first support column (121) and / or the second support column (1221). The height adjustment device is used to adjust the height of the support end face of the first support column (121) and the preset second support column (1221) to the same horizontal height.

5. The pre-alignment device according to claim 2, characterized in that, The support end faces of the two second support columns (1221) in each set of support components (122) are located on the same horizontal plane, and the height of the second support column (1221) gradually increases in the direction away from the first support column (121); The support assembly (12) further includes a second lifting drive (123), which is connected to the first support column (121) and drives the first support column (121) to rise and fall to be flush with the support end face of the second support column (1221) in one of the support components (122) to horizontally support one of the wafers.

6. The pre-alignment device according to any one of claims 3-5, characterized in that, The driving component (132) includes a first horizontal driving component (1321), a first lifting driving component (1322), and a first rotary driving component (1323). The first horizontal driving component (1321) is driven and connected to the first lifting driving component (1322). The first horizontal driving component (1321) is used to drive the first lifting driving component (1322) to move along the first direction. The first lifting driving component (1322) is driven and connected to the first rotary driving component (1323). The first lifting driving component (1322) is used to drive the first rotary driving component (1323) to lift. The first rotary driving component (1323) is provided with the output shaft (13231). The output shaft (13231) passes through the elongated hole (1111) and is connected to the tray (131). The first rotary driving component (1323) is used to drive the tray (131) to rotate.

7. The pre-alignment device according to any one of claims 1-5, characterized in that, The detection device (2) further includes a buffer component (23), which is installed at the bottom of the housing (21). The buffer component (23) and the camera (22) are spaced apart along a first direction. The buffer component (23) includes a non-contact suction cup (231) for adsorbing the wafer.

8. The pre-alignment device according to claim 7, characterized in that, The buffer assembly (23) further includes a third lifting drive (232), a mounting base plate (233), a mounting plate (234), and multiple positioning pins (235). The third lifting drive (232) is connected to the housing (21) and driven to the mounting base plate (233). The third lifting drive (232) is used to drive the mounting base plate (233) to lift. The mounting plate (234) and the non-contact suction cup (231) are both mounted on the mounting base plate (233). Multiple positioning pins (235) are disposed on the mounting plate (234), and multiple positioning pins (235) are arranged around the non-contact chuck (231). The wafer can be embedded between multiple positioning pins (235).

9. The pre-alignment device according to claim 8, characterized in that, The non-contact suction cup (231) is a Bernoulli suction cup or an electrostatic suction cup.

10. The pre-alignment device according to claim 8, characterized in that, The positioning pin (235) has a tapered portion (2351) at one end away from the mounting plate (234). The sidewalls of the multiple positioning pins (235) near the non-contact chuck (231) form a first circle, and the centers of the tapered portions (2351) of the multiple positioning pins (235) form a second circle. The diameter of the wafer is between the diameter of the first circle and the diameter of the second circle.

11. An alignment method, characterized in that, Applied to the pre-aligner as described in any one of claims 1-10, the alignment method includes the following steps; S1. Place the wafer horizontally on the first support pillar (121) and the two second support pillars (1221); S2. The driving component (132) drives the tray (131) to move below the wafer, lifts the wafer and drives the wafer to rotate at a preset angle. When the wafer rotates, the camera (22) acquires the contour information of the wafer edge and calculates the center coordinates of the wafer. The eccentricity of the wafer is calculated based on the center coordinates. S3. The driving component (132) drives the wafer to rotate according to the eccentricity data calculated in step S2, so that the line connecting the center of the wafer and the center of the tray (131) is located in the first direction. S4. After the driving component (132) drives the tray (131) to descend to a horizontal height lower than the first support column (121), the wafer is supported by the first support column (121) and one of the second support columns (1221). Then the tray (131) moves along the first direction to directly below the wafer, and the center of the wafer and the center of the tray (131) are on the same vertical line. S5. The driving component (132) drives the tray (131) to move upward and lift the wafer to complete the center calibration of the wafer.

12. The alignment method according to claim 11, characterized in that, When the edge of the wafer is provided with a notch or a flat edge, step S2 further includes the camera (22) acquiring the coordinates of the notch or flat edge; The alignment method further includes: S6. The driving component (132) drives the tray (131) to rotate so that the line connecting the center of the notch or the center of the flat edge with the center of the tray (131) is located in the first direction.

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