Method for detecting wafer position, wafer girdling method and wafer girdling device
By installing an equilateral triangle arrangement sensor on the chuck, we obtain the wafer edge coordinates and calculate the center coordinates and judge the position offset, solving the problem of position offset during wafer circumcision in semiconductor manufacturing, improving performance and manufacturing The yield reduces manufacturing costs.
Patent Information
- Application Number
- CN202411253638.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-06
- Publication Date
- 2024-12-13
Smart Images
Figure CN119133024A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor manufacturing technology, and in particular to a method for detecting a wafer position, a wafer ring cutting method and a wafer ring cutting device. Background Art
[0002] In the manufacturing process of the semiconductor structure, after the manufacturing process of the semiconductor device is completed on the front side of the wafer, a front protective film is covered on the front side of the wafer, and the back side of the wafer is thinned, for example, the back side of the wafer is thinned using a dual-axis process. After the thinning process, the front protective film on the front side of the wafer is removed. Next, the back side of the wafer is wet cleaned to remove the rough lines produced on the back side of the wafer during the grinding process to effectively reduce the contact resistance. After that, a metal material is deposited on the back side of the wafer to form a back metal layer. Then, the semiconductor structure formed by the above process is tested for electrical properties. Next, a back protective film is attached to the side of the back metal layer away from the wafer, and the wafer is ring-cut to remove the wafer ring (i.e., ring) at the edge of the wafer. After the ring-cut process, the wafer is cut to form multiple independent chips. However, during the current wafer ring cutting process, the position of the wafer is easily shifted, which may cause damage to the wafer during the ring cutting process, such as fragmentation, which ultimately affects the performance and manufacturing yield of the semiconductor structure.
[0003] Therefore, how to avoid the position shift of the wafer and ensure the smooth progress of semiconductor processes such as the ring cutting process, so as to improve the performance and manufacturing yield of the semiconductor structure, is a technical problem that needs to be solved urgently. Summary of the invention
[0004] The present invention provides a method for detecting the position of a wafer, a wafer ring cutting method and a wafer ring cutting device, which are used to avoid the position of the wafer from being offset and ensure the smooth progress of semiconductor processes such as the ring cutting process, thereby improving the performance and manufacturing yield of the semiconductor structure.
[0005] According to some embodiments, the present invention provides a method for detecting a wafer position, comprising the following steps:
[0006] Providing a chuck, the chuck comprising a carrying surface for carrying a wafer, the center of the carrying surface having a carrying center coordinate;
[0007] placing a wafer on the chuck;
[0008] Acquire edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface;
[0009] Calculating the coordinates of the center of the wafer according to the plurality of edge coordinates as the wafer center position coordinates;
[0010] It is determined whether the wafer center position coordinates coincide with the bearing center coordinates. If not, it is determined that the position of the wafer on the chuck is offset.
[0011] In some embodiments, before placing the wafer on the chuck, the following steps are also included:
[0012] Three sensors arranged in an equilateral triangle are installed on the edge of the chuck, and the projection of the center of the equilateral triangle formed by the connection lines of the three sensors on the carrying surface coincides with the center of the carrying surface.
[0013] In some embodiments, the sensor is a contactless sensor.
[0014] In some embodiments, the specific steps of obtaining edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface include:
[0015] An edge coordinate of an edge position of the wafer detected by each sensor relative to the center of the carrying surface is respectively obtained.
[0016] In some embodiments, the specific steps of calculating the coordinates of the center of the wafer according to the plurality of edge coordinates as the coordinates of the center position of the wafer include:
[0017] According to the method for calculating the center coordinates of an equilateral triangle, the coordinates of the center of the wafer are calculated using the three edge coordinates detected by the three sensors as the center position coordinates of the wafer.
[0018] According to some other embodiments, the present invention further provides a wafer ring cutting method, comprising the following steps:
[0019] Providing a chuck, the chuck comprising a carrying surface for carrying a wafer, the center of the carrying surface having a carrying center coordinate;
[0020] Placing a wafer on the chuck, wherein the edge of the wafer has a wafer ring;
[0021] Acquire edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface;
[0022] Calculating the coordinates of the center of the wafer according to the plurality of edge coordinates as the wafer center position coordinates;
[0023] Determine whether the wafer center position coordinates coincide with the bearing center coordinates, and if so, cut the wafer along the wafer ring.
[0024] In some embodiments, before placing the wafer on the chuck, the following steps are also included:
[0025] Three sensors arranged in an equilateral triangle are installed on the edge of the chuck, and the projection of the center of the equilateral triangle formed by the connection lines of the three sensors on the carrying surface coincides with the center of the carrying surface.
[0026] In some embodiments, the following steps are also included:
[0027] It is determined whether the wafer center position coordinates coincide with the bearing center coordinates. If not, it is determined that the position of the wafer on the chuck is offset, and the wafer ring cutting process is stopped.
[0028] According to some further embodiments, the present invention further provides a wafer ring cutting device, comprising:
[0029] A chuck, the chuck comprising a bearing surface for bearing a wafer, the center of the bearing surface having a bearing center coordinate;
[0030] A detection structure, located at the edge of the chuck, for obtaining edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface;
[0031] A control structure is connected to the detection structure and is used to determine whether the center position coordinates of the wafer coincide with the bearing center coordinates. If so, the wafer is cut along the wafer ring.
[0032] In some embodiments, the detection structure includes three sensors arranged in an equilateral triangle at the edge of the chuck, and the projection of the center of the equilateral triangle formed by the connection of the three sensors on the carrying surface coincides with the center of the carrying surface;
[0033] The sensor is used to obtain an edge coordinate of an edge position of the wafer relative to the center of the carrying surface.
[0034] In some embodiments, the sensor is a contactless sensor.
[0035] The method for detecting the position of a wafer, the wafer ring cutting method and the wafer ring cutting device provided by the present invention obtain the edge coordinates of multiple positions on the edge of a wafer placed on a chuck relative to the center of the bearing surface of the chuck, calculate the coordinates of the center of the wafer according to the multiple edge coordinates as the wafer center position coordinates, and determine whether the position of the wafer on the chuck is offset according to whether the wafer center position coordinates coincide with the bearing center coordinates. On the one hand, it can ensure the smooth progress of subsequent processes such as wafer ring cutting and avoid damage such as fragments to the wafer, thereby improving the performance and manufacturing yield of the semiconductor structure. On the other hand, the position of the wafer can be indirectly determined by only obtaining the coordinates of the wafer edge, the operation is simple, and the detection cost is low, thereby helping to reduce the manufacturing cost of the semiconductor structure. BRIEF DESCRIPTION OF THE DRAWINGS
[0036] Figure 1 is a flow chart of a method for detecting wafer position in a specific embodiment of the present invention;
[0037] Figure 2 is a schematic diagram of the structure after the sensor is installed on the edge of the chuck in a specific embodiment of the present invention;
[0038] Figure 3 is a schematic diagram of the structure after a wafer is placed on a chuck in a specific embodiment of the present invention;
[0039] Figure 4 It is a flow chart of a wafer ring cutting method in a specific implementation manner of the present invention. DETAILED DESCRIPTION
[0040] The specific implementation methods of the method for detecting the position of a wafer, the wafer ring cutting method and the wafer ring cutting device provided by the present invention are described in detail below with reference to the accompanying drawings.
[0041] This specific embodiment provides a method for detecting the position of a wafer. Figure 1 1 is a flow chart of a method for detecting wafer position in a specific embodiment of the present invention. Figure 1 As shown, the method for detecting the wafer position comprises the following steps:
[0042] Step S11, providing a chuck, wherein the chuck comprises a bearing surface for bearing a wafer, and the center of the bearing surface has a bearing center coordinate;
[0043] Step S12, placing the wafer on the chuck;
[0044] Step S13, obtaining edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface;
[0045] Step S14, calculating the coordinates of the center of the wafer according to the plurality of edge coordinates as the wafer center position coordinates;
[0046] Step S15, determining whether the wafer center position coordinates coincide with the bearing center coordinates, and if not, determining that the position of the wafer on the chuck is offset.
[0047] Figure 2 2 is a schematic diagram of the structure after the sensor is installed on the edge of the chuck in a specific embodiment of the present invention. In some embodiments, before placing the wafer on the chuck 20, the following steps are also included:
[0048] Three sensors 21 arranged in an equilateral triangle are installed on the edge of the chuck 20, and the projection of the center of the equilateral triangle 22 formed by the three sensors 21 on the carrying surface 201 coincides with the center of the carrying surface 201. Figure 2 shown.
[0049] For example, the chuck 20 includes the relatively distributed carrying surface 201 and the back surface, and the carrying surface 201 is used to carry the wafer. Three sensors 21 are arranged on the carrying surface 201 of the chuck 20, and the three sensors 21 are connected end to end on the carrying surface 201 to form an equilateral triangle 22 (i.e., a triangle formed by the three sensors 21 as three vertices), so that the projection of the center of the equilateral triangle 22 formed by the connecting line of the three sensors 21 on the carrying surface 201 coincides with the center of the carrying surface 201. Directly connecting the three sensors 21 to the chuck 20 can shorten the distance between the sensor and the wafer in the subsequent detection process, thereby helping to improve the accuracy and reliability of the detection. Figure 2 The dotted lines in the figure are used to indicate the positional relationship of the three sensors 21 arranged in an equilateral triangle. In an actual chuck, there is no connection between the three sensors 21 .
[0050] In some embodiments, the sensor 21 is a non-contact sensor to avoid damage to the wafer (especially the edge of the wafer). In one example, the sensor 21 is an optical sensor.
[0051] Figure 3 is a schematic diagram of the structure after the wafer is placed on the chuck in a specific embodiment of the present invention. Figure 3 As shown, the specific steps of obtaining edge coordinates of multiple positions on the edge of the wafer 30 relative to the center of the carrying surface 201 include:
[0052] An edge coordinate of an edge position of the wafer 30 detected by each sensor 21 relative to the center of the carrying surface is obtained respectively.
[0053] In some embodiments, the specific steps of calculating the coordinates of the center of the wafer 30 according to the plurality of edge coordinates as the coordinates of the wafer center position include:
[0054] According to the method of calculating the center coordinates of an equilateral triangle, the coordinates of the center of the wafer 30 are calculated using the three edge coordinates detected by the three sensors 21 as the wafer center position coordinates.
[0055] For example, the sensor 21 is a position sensor. The three sensors 21 detect the coordinates of three positions of the edge of the wafer 30 relative to the center of the carrying surface 201 one by one, and the coordinate of one position of the edge of the wafer 30 relative to the center of the carrying surface 201 detected by each sensor 21 is used as an edge coordinate. Figure 3 The solid arrow in the figure schematically indicates the direction in which the sensor 21 emits the detection signal. According to the method for calculating the center coordinate of an equilateral triangle, the edge coordinate detected by each sensor 21 is used as the coordinate of a vertex of the equilateral triangle to calculate the center coordinate of the equilateral triangle, and the calculated center coordinate of the equilateral triangle is used as the coordinate of the center of the wafer 30 (i.e., the wafer center position coordinate). It is determined whether the wafer center position coordinate is the same as the bearing center coordinate. If not, it is determined that the position of the wafer 30 on the chuck 20 is offset. If the wafer center position coordinate is the same as the bearing center coordinate, it is determined that the position of the wafer 30 on the chuck 20 is not offset. In one example, the bearing center coordinate is the origin coordinate.
[0056] This specific implementation method obtains the coordinates of the edge position of the wafer, determines the position of the center of the wafer based on the coordinates of the edge position of the wafer, and determines whether the position of the wafer on the chuck is offset based on whether the coordinates of the center position of the wafer coincide with the coordinates of the support center. This can quickly and accurately determine whether the position of the wafer on the chuck is offset, thereby avoiding the subjectivity of human eye observation and judgment, and is simple to operate. It only needs to set detection structures such as position sensors on the edge of the chuck, and the detection cost is low.
[0057] This specific embodiment also provides a wafer ring cutting method, Figure 4 1 is a flow chart of a wafer ring cutting method in a specific embodiment of the present invention. The wafer ring cutting method can be implemented as follows: Figure 2 and Figure 3 The device shown is implemented. Figure 2-Figure 4 As shown, the wafer ring cutting method comprises the following steps:
[0058] Step S41, providing a chuck 20, wherein the chuck 20 comprises a carrying surface 201 for carrying the wafer 30, and the center of the carrying surface 201 has a carrying center coordinate;
[0059] Step S42, placing the wafer 30 on the chuck 20, wherein the edge of the wafer 30 has a wafer ring;
[0060] Step S43, obtaining edge coordinates of a plurality of positions on the edge of the wafer 30 relative to the center of the carrying surface 201;
[0061] Step S44, calculating the coordinates of the center of the wafer 30 according to the plurality of edge coordinates as the wafer center position coordinates;
[0062] Step S45 , determining whether the wafer center position coordinates coincide with the bearing center coordinates, and if so, cutting the wafer 30 along the wafer ring.
[0063] In some embodiments, before placing the wafer 30 on the chuck 20, the following steps are further included:
[0064] Three sensors 21 arranged in an equilateral triangle are installed on the edge of the chuck 20 , and the projection of the center of the equilateral triangle formed by the three sensors 21 on the carrying surface 201 coincides with the center of the carrying surface 201 .
[0065] In some embodiments, the wafer ring cutting method further comprises the following steps:
[0066] It is determined whether the wafer center position coordinates coincide with the bearing center coordinates. If not, it is determined that the position of the wafer 30 on the chuck 20 is offset, and the wafer ring cutting process is stopped.
[0067] The multiple mentioned in this specific embodiment refers to more than two. For example, after the wafer 30 is transferred to the carrying surface 201 of the chuck 20, the three sensors 21 located on the chuck 20 detect the coordinates of the three positions of the edge of the wafer 30 relative to the center of the carrying surface 201 one by one, and the coordinates of one position of the edge of the wafer 30 relative to the center of the carrying surface 201 detected by each sensor 21 are used as an edge coordinate. According to the method of calculating the center coordinate of an equilateral triangle, the edge coordinate detected by each sensor 21 is used as the coordinate of a vertex of the equilateral triangle, the center coordinate of the equilateral triangle is calculated, and the calculated center coordinate of the equilateral triangle is used as the coordinate of the center of the wafer 30 (i.e., the center position coordinate of the wafer). It is determined whether the center position coordinate of the wafer is the same as the center coordinate of the bearing center. If not, it is determined that the position of the wafer 30 on the chuck 20 is offset, and the wafer ring cutting process is stopped to avoid damage to the wafer 30. If the wafer center position coordinates are the same as the bearing center coordinates, it is determined that the position of the wafer 30 on the chuck 20 has not shifted, and the wafer 30 is cut along the wafer ring.
[0068] This specific embodiment also provides a wafer ring cutting device. The schematic diagram of the wafer ring cutting device can be seen in Figure 2 and Figure 3 The wafer ring cutting device can be used as follows. Figure 4The wafer ring cutting method shown in the figure performs a ring cutting process on the wafer. Figure 2 and Figure 3 As shown, the wafer ring cutting device comprises:
[0069] A chuck 20, wherein the chuck 20 comprises a carrying surface 201 for carrying a wafer 30, wherein the center of the carrying surface 201 has a carrying center coordinate, and the edge of the wafer 30 has a wafer ring;
[0070] A detection structure, located at the edge of the chuck 20, for obtaining edge coordinates of multiple positions on the edge of the wafer relative to the center of the carrying surface 201;
[0071] The control structure is connected to the detection structure and is used to determine whether the wafer center position coordinates coincide with the bearing center coordinates. If so, the wafer 30 is cut along the wafer ring.
[0072] In some embodiments, the detection structure includes three sensors arranged in an equilateral triangle at the edge of the chuck, and the projection of the center of the equilateral triangle formed by the three sensors 21 on the carrying surface 201 coincides with the center of the carrying surface 201;
[0073] The sensor 21 is used to obtain an edge coordinate of an edge position of the wafer 30 relative to the center of the carrying surface 201 .
[0074] In some embodiments, the sensor 21 is a non-contact sensor to avoid damage to the wafer (especially the edge of the wafer). In one example, the sensor 21 is an optical sensor.
[0075] The method for detecting the position of a wafer, the wafer ring cutting method and the wafer ring cutting device provided in this specific embodiment obtain the edge coordinates of multiple positions on the edge of the wafer placed on the chuck relative to the center of the bearing surface of the chuck, calculate the coordinates of the center of the wafer according to the multiple edge coordinates as the wafer center position coordinates, and determine whether the position of the wafer on the chuck is offset according to whether the wafer center position coordinates coincide with the bearing center coordinates. On the one hand, it can ensure the smooth progress of subsequent processes such as wafer ring cutting, avoid damage to the wafer such as fragments, and improve the performance and manufacturing yield of the semiconductor structure. On the other hand, the position of the wafer can be indirectly determined by only obtaining the coordinates of the wafer edge. The operation is simple and the detection cost is low, which helps to reduce the manufacturing cost of the semiconductor structure.
[0076] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A method for detecting a wafer position, characterized in that: The steps include: Providing a chuck, the chuck comprising a carrying surface for carrying a wafer, the center of the carrying surface having a carrying center coordinate; placing a wafer on the chuck; Acquire edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface; Calculating the coordinates of the center of the wafer according to the plurality of edge coordinates as the wafer center position coordinates; It is determined whether the wafer center position coordinates coincide with the bearing center coordinates. If not, it is determined that the position of the wafer on the chuck is offset.
2. The method for detecting wafer position according to claim 1, characterized in that: Before placing the wafer on the chuck, the following steps are also included: Three sensors arranged in an equilateral triangle are installed on the edge of the chuck, and the projection of the center of the equilateral triangle formed by the connection lines of the three sensors on the carrying surface coincides with the center of the carrying surface.
3. The method for detecting wafer position according to claim 2, characterized in that: The sensor is a non-contact sensor.
4. The method for detecting wafer position according to claim 2, characterized in that: The specific step of obtaining edge coordinates of multiple positions on the edge of the wafer relative to the center of the carrying surface includes: respectively obtaining an edge coordinate of an edge position of the wafer detected by each sensor relative to the center of the carrying surface.
5. The method for detecting wafer position according to claim 4, characterized in that: The specific steps of calculating the coordinates of the center of the wafer according to the plurality of edge coordinates as the coordinates of the center position of the wafer include: According to the method for calculating the center coordinates of an equilateral triangle, the coordinates of the center of the wafer are calculated using the three edge coordinates detected by the three sensors as the center position coordinates of the wafer.
6. A wafer ring cutting method, characterized in that: The steps include: Providing a chuck, the chuck comprising a carrying surface for carrying a wafer, the center of the carrying surface having a carrying center coordinate; Placing a wafer on the chuck, wherein the edge of the wafer has a wafer ring; Acquire edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface; Calculating the coordinates of the center of the wafer according to the plurality of edge coordinates as the wafer center position coordinates; Determine whether the wafer center position coordinates coincide with the bearing center coordinates, and if so, cut the wafer along the wafer ring.
7. The wafer ring cutting method according to claim 6, characterized in that: Before placing the wafer on the chuck, the following steps are also included: Three sensors arranged in an equilateral triangle are installed on the edge of the chuck, and the projection of the center of the equilateral triangle formed by the connection lines of the three sensors on the carrying surface coincides with the center of the carrying surface.
8. The wafer ring cutting method according to claim 6, characterized in that: The following steps are also included: It is determined whether the wafer center position coordinates coincide with the bearing center coordinates. If not, it is determined that the position of the wafer on the chuck is offset, and the wafer ring cutting process is stopped.
9. A wafer ring cutting device, characterized in that: include: A chuck, the chuck comprising a bearing surface for bearing a wafer, the center of the bearing surface having a bearing center coordinate, and the edge of the wafer having a wafer ring; A detection structure, located at the edge of the chuck, for obtaining edge coordinates of a plurality of positions on the edge of the wafer relative to the center of the carrying surface; A control structure is connected to the detection structure and is used to determine whether the center position coordinates of the wafer coincide with the bearing center coordinates. If so, the wafer is cut along the wafer ring.
10. The wafer ring cutting device according to claim 9, characterized in that: The detection structure includes three sensors arranged in an equilateral triangle at the edge of the chuck, and the projection of the center of the equilateral triangle formed by the connection of the three sensors on the carrying surface coincides with the center of the carrying surface; The sensor is used to obtain an edge coordinate of an edge position of the wafer relative to the center of the carrying surface.
11. The wafer ring cutting device according to claim 9, characterized in that: The sensor is a non-contact sensor.