Method for detecting wafer bonding alignment deviation

Abstract

The invention provides a method for detecting wafer bonding alignment deviation. The method comprises the steps that a preset number of metal test points are arranged on two wafers to be bonded according to preset coordinates, and every two metal test points on a first wafer and every two metal test points on a second wafer serve as a test loop; detecting the conduction condition of each group of test loops after the two wafers are bonded; and determining the bonding alignment deviation between the two wafers according to the conduction condition of each group of test loops. According to the invention, the detection precision of the wafer bonding alignment deviation can be improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a method for detecting wafer bonding alignment deviations. Background Technology

[0002] With the challenges posed by Moore's Law and the continuous increase in costs, advanced packaging technology has become one of the key factors driving the development of the semiconductor industry. Advanced packaging improves chip performance, integration, functionality, and reliability by optimizing chip packaging methods, while reducing size and weight, meeting the demands of modern electronic devices for high performance, high reliability, and miniaturization.

[0003] 3D packaging technology is an advanced packaging technology that allows two or more wafers to be stacked vertically within a package and electrically connected directly to each other. The realization of 3D packaging relies on several key processes, including hybrid bonding. Hybrid bonding eliminates the need for traditional bumps, enabling more connection points in a smaller space, thereby improving data communication bandwidth and signal transmission efficiency.

[0004] Hybrid bonding processes typically involve metal interconnects at the interface, which are connected through specific process steps. Due to the small spacing between metal interconnects in hybrid bonding, high process precision is required. After bonding, it is necessary to detect the bonding alignment deviation of the chip to ensure electrical performance and reliability.

[0005] Currently, alignment deviation detection after hybrid bonding is mainly achieved through optical inspection. Alignment marks are designed on the two wafers requiring precision inspection. Under ideal bonding conditions, these alignment marks should perfectly overlap. After hybrid bonding, taking advantage of the wafer's ability to see through infrared light, near-infrared light with a wavelength of approximately 1100 nm is used for optical inspection. Simultaneously, the positions of the alignment marks on the two wafers are observed and measured, thus obtaining the relative positional difference between the two wafers, i.e., the alignment deviation.

[0006] Using the above method, the resolution of using 1100nm infrared light can typically be calculated to be 1µm in practice. When the required spacing of hybrid bonds is less than 3-5µm, the resolution becomes increasingly close to the distance to be measured, and the above optical detection method may not be able to accurately determine the bonding alignment deviation. Summary of the Invention

[0007] The method for detecting wafer bonding alignment deviation provided by this invention can improve the detection accuracy of wafer bonding alignment deviation.

[0008] In a first aspect, the present invention provides a method for detecting wafer bonding alignment deviation, the method comprising: A predetermined number of metal test points are set on the two wafers to be bonded according to predetermined coordinates. Each metal test point on the first wafer and each metal test point on the second wafer are connected in pairs as a test loop. The continuity of each test circuit is tested after the two wafers are bonded together. Based on the continuity of each test circuit, the bonding alignment deviation between the two wafers is determined.

[0009] Optionally, setting a predetermined number of metal test points on the two wafers to be bonded according to predetermined coordinates includes: On the two wafers to be bonded, a predetermined number of first metal test points are set according to predetermined coordinates to detect the bonding alignment deviation in the X-axis direction, and a predetermined number of second metal test points are set according to predetermined coordinates to detect the bonding alignment deviation in the Y-axis direction. In this configuration, each first metal test point on the first wafer and each first metal test point on the second wafer are paired together to form a test circuit, and each second metal test point on the first wafer and each second metal test point on the second wafer are paired together to form a test circuit.

[0010] Optionally, determining the bonding alignment deviation between the two wafers based on the continuity of each set of test circuits includes: Based on the continuity of each test circuit formed by the first metal test points on the first wafer and the first metal test points on the second wafer, the bonding alignment deviation between the two wafers in the X-axis direction is determined. Based on the continuity of each test circuit formed by each second metal test point on the first wafer and each second metal test point on the second wafer, the bonding alignment deviation between the two wafers in the Y-axis direction is determined. The overall bonding alignment deviation between the two wafers is determined based on the bonding alignment deviation between the two wafers in the X-axis direction and the bonding alignment deviation between the two wafers in the Y-axis direction.

[0011] Optionally, determining the overall bonding alignment deviation between the two wafers based on the bonding alignment deviation between the two wafers in the X-axis direction and the bonding alignment deviation between the two wafers in the Y-axis direction includes: Based on the bonding alignment deviation between the two wafers in the X-axis direction and the bonding alignment deviation between the two wafers in the Y-axis direction, the range of bonding alignment deviation between the two wafers in the Cartesian coordinate system is determined.

[0012] Optionally, setting a predetermined number of first metal test points on the two wafers to be bonded according to predetermined coordinates for detecting bonding alignment deviation in the X-axis direction includes: Multiple circular metal test points P0~Pn are set on the first wafer, each with a radius of R. The coordinates of the center of each test point in the rectangular coordinate system are (X, R, ..., Pn). P0 Y P0 )~(X Pn Y Pn The coordinate relationship between the centers of the test points is X. Pn =X Pn-1 +R, Y Pn =Y Pn-1 +a; Multiple circular metal test points Q0~Qn are set on the second wafer. The radius of each test point is R, and the coordinates of the center of each test point in the rectangular coordinate system are (X, Qn) respectively. Q0 Y Q0 )~(X Qn Y Qn The x-coordinate of the center of each test point is X. Q0 =X Q1 =…=X Qn The ordinate Y of the center of each test point Q0 =Y P0 Y Q1 =Y P1 Y Qn =Y Pn ; Among them, X Q0 =X P0 +2R, n≥1, a>2R.

[0013] Optionally, the center coordinates of the first wafer are (X... P0 Y P0 The test point and the center of the second wafer are located at coordinates (X, X). Q0 Y Q0 The test points are arranged in a test loop, with the center coordinates of the first wafer being (X...). Pn Y Pn The test point and the center of the second wafer are located at coordinates (X, X). Qn Y Qn The test points are grouped together as a test loop, and so on.

[0014] Optionally, setting a predetermined number of second metal test points on the two wafers to be bonded according to predetermined coordinates for detecting bonding alignment deviation in the Y-axis direction includes: Multiple circular metal test points K0~Kn are set on the first wafer, each with a radius of R, and the coordinates of the center of each test point in the rectangular coordinate system are (X, Y, Kn) respectively. K0 Y K0 )~(X Kn Y KnThe coordinate relationship between the centers of the test points is Y. Kn =Y Kn-1 +R, X Kn =X Kn-1 +b; Multiple circular metal test points L0~Ln are set on the second wafer, each with a radius of R, and the coordinates of the center of each test point in the rectangular coordinate system are (X, R) and (X, R). L0 Y L0 )~(X Ln Y Ln The ordinate Y of the center of each test point L0 =Y L1 =…=Y Ln The x-coordinate of the center of each test point L0 =X K0 X L1 =X K1 , ..., X Ln =X Kn ; Among them, Y L0 =Y K0 +2R, n≥1, b>2R.

[0015] Optionally, the center coordinates of the first wafer are (X... K0 Y K0 The test point and the center of the second wafer are located at coordinates (X, X). L0 Y L0 The test points are arranged in a test loop, with the center coordinates of the first wafer being (X...). Ln Y Ln The test point and the center of the second wafer are located at coordinates (X, X). Ln Y Ln The test points are grouped together as a test loop, and so on.

[0016] Optionally, when the test circuit formed by the circular metal test points on the first wafer and the circular metal test points on the second wafer is conductive, the circular metal test points on the first wafer and the circular metal test points on the second wafer intersect or overlap; when the test circuit formed by the circular metal test points on the first wafer and the circular metal test points on the second wafer is not conductive, the circular metal test points on the first wafer and the circular metal test points on the second wafer are tangent or separate.

[0017] Optionally, the metal test points are fabricated simultaneously with the metal connection points on both sides of the wafer bonding interface.

[0018] The method for detecting wafer bonding alignment deviation provided in this invention involves simultaneously fabricating a predetermined number of metal test points distributed according to predetermined coordinates at the metal connection points on both sides of the wafer bonding interface during the semiconductor manufacturing process. The test points on the first wafer and the test points on the second wafer form a test loop in pairs. Based on the detected continuity of each test loop, the bonding alignment deviation between the two wafers can be determined. Compared with existing technologies, this invention does not require a separate optical inspection device, and the detection of the continuity of the test loops can be performed simultaneously with the routine continuity detection after wafer bonding. The detection accuracy of wafer bonding alignment deviation is related to the size of the test points; by controlling the size of the test points, the detection accuracy of wafer bonding alignment deviation can be effectively improved. Attached Figure Description

[0019] Figure 1 This is a flowchart of a method for detecting wafer bonding alignment deviation according to an embodiment of the present invention; Figure 2 This is a flowchart of a method for detecting wafer bonding alignment deviation according to another embodiment of the present invention; Figure 3a A schematic diagram showing the distribution of test points on the first wafer for detecting bonding alignment deviation in the X-axis direction, provided in an embodiment of the present invention; Figure 3b A schematic diagram showing the distribution of test points on the second wafer provided in an embodiment of the present invention for detecting bonding alignment deviation in the X-axis direction; Figures 4a-4f This is a schematic diagram showing the positional relationship of each test point for detecting bonding alignment deviation in the X-axis direction after bonding two wafers, as provided in an embodiment of the present invention. Figure 5a A schematic diagram showing the distribution of test points on the first wafer for detecting bonding alignment deviation in the Y-axis direction, provided in an embodiment of the present invention; Figure 5b A schematic diagram showing the distribution of test points on the second wafer provided in an embodiment of the present invention for detecting bonding alignment deviation in the Y-axis direction; Figures 6a-6f This is a schematic diagram showing the positional relationship of each test point used to detect Y-axis bonding alignment deviation after bonding two wafers, as provided in an embodiment of the present invention. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention provides a method for detecting wafer bonding alignment deviations, such as... Figure 1 As shown, the method includes: S11. Set a predetermined number of metal test points on the two wafers to be bonded according to predetermined coordinates, wherein each metal test point on the first wafer and each metal test point on the second wafer are connected in pairs as a test loop.

[0022] S12. Detect the continuity of each test circuit after the two wafers are bonded.

[0023] S13. Determine the bonding alignment deviation between the two wafers based on the continuity of each test circuit.

[0024] The method for detecting wafer bonding alignment deviation provided in this invention involves simultaneously fabricating a predetermined number of metal test points distributed according to predetermined coordinates at the metal connection points on both sides of the wafer bonding interface during the semiconductor manufacturing process. The test points on the first wafer and the test points on the second wafer form a test loop in pairs. Based on the detected continuity of each test loop, the bonding alignment deviation between the two wafers can be determined. Compared with existing technologies, this invention does not require a separate optical inspection device, and the detection of the continuity of the test loops can be performed simultaneously with the routine continuity detection after wafer bonding. The detection accuracy of wafer bonding alignment deviation is related to the size of the test points; by controlling the size of the test points, the detection accuracy of wafer bonding alignment deviation can be effectively improved.

[0025] The method for detecting wafer bonding alignment deviation of the present invention will be described in detail below with reference to specific embodiments.

[0026] like Figure 2 As shown, the method for detecting wafer bonding alignment deviation provided in this embodiment includes the following steps: S21. On the two wafers to be bonded, a predetermined number of first metal test points are set according to predetermined coordinates to detect the bonding alignment deviation in the X-axis direction, and on the two wafers to be bonded, a predetermined number of second metal test points are set according to predetermined coordinates to detect the bonding alignment deviation in the Y-axis direction.

[0027] Specifically, such as Figure 3aAs shown, multiple circular metal test points P0~Pn are set on the first wafer to be bonded, with a radius of R for each test point. The coordinates of the center of each test point in the rectangular coordinate system are (X, R, ..., Pn). P0 Y P0 )~(X Pn Y Pn The coordinate relationship between the centers of the test points is X. Pn =X Pn-1 +R, Y Pn =Y Pn-1 +a, where n≥1, a>2R.

[0028] like Figure 3b As shown, multiple circular metal test points Q0~Qn are set on the second wafer to be bonded, with a radius of R for each test point. The coordinates of the center of each test point in the rectangular coordinate system are (X, Qn, Qn) respectively. Q0 Y Q0 )~(X Qn Y Qn The x-coordinate of the center of each test point remains consistent, i.e., X Q0 =X Q1 =…=X Qn The ordinate of the center of each test point satisfies Y Q0 =Y P0 Y Q1 =Y P1 , ..., Y Qn =Y Pn , where X Q0 =X P0 +2R, n≥1.

[0029] Test points P0 and Q0 form a test loop, test points P1 and Q1 form a test loop, and so on.

[0030] Specifically, such as Figure 5a As shown, multiple circular metal test points K0~Kn are set on the first wafer to be bonded, with a radius of R for each test point. The coordinates of the center of each test point in the rectangular coordinate system are (X, Kn) respectively. K0 Y K0 )~(X Kn Y Kn The coordinate relationship between the centers of the test points is Y. Kn =Y Kn-1 +R, X Kn =X Kn-1 +b, where n≥1, b>2R.

[0031] like Figure 5bAs shown, multiple circular metal test points L0~Ln are set on the second wafer to be bonded, with a radius of R for each test point. The coordinates of the center of each test point in the rectangular coordinate system are (X, R, Ln) respectively. L0 Y L0 )~(X Ln Y Ln The ordinate of the center of each test point remains consistent, i.e., Y... L0 =Y L1 =…=Y Ln The x-coordinate of the center of each test point satisfies X L0 =X K0 X L1 =X K1 , ..., X Ln =X Kn , where Y L0 =Y K0 +2R, n≥1.

[0032] Test points K0 and L0 form a test loop, test points K1 and L1 form a test loop, and so on.

[0033] Each metal test point can be fabricated simultaneously with the metal connection points on both sides of the wafer bonding interface.

[0034] S22. Detect the continuity of each test circuit formed by each first metal test point on the first wafer and each first metal test point on the second wafer after wafer bonding, and detect the continuity of each test circuit formed by each second metal test point on the first wafer and each second metal test point on the second wafer after wafer bonding.

[0035] After pre-bonding and full bonding, the first and second wafers may have alignment deviations, and different test circuits may be conductive or non-conductive. After setting the test points in the above manner, if the two circular test points forming the same test circuit intersect or coincide, the test circuit is conductive; if the two circular test points forming the same test circuit are tangent or separate, the test circuit is non-conductive.

[0036] S23. Based on the continuity of each test circuit formed by each first metal test point on the first wafer and each first metal test point on the second wafer, determine the bonding alignment deviation between the two wafers in the X-axis direction; and based on the continuity of each test circuit formed by each second metal test point on the first wafer and each second metal test point on the second wafer, determine the bonding alignment deviation between the two wafers in the Y-axis direction.

[0037] Specifically, when determining the bonding alignment deviation between two wafers in the X-axis direction, we will take as an example five test circuits formed by setting five circular metal test points P0-P4 (shown by solid circles) on the first wafer and five circular metal test points Q0-Q4 (shown by dashed circles) on the second wafer.

[0038] Under the ideal condition that the first wafer and the second wafer are perfectly aligned in the X-axis direction after bonding, the test points set in the above manner are: P0 and Q0 are tangent, P1 and Q1 intersect, P2 and Q2 coincide, P3 and Q3 intersect, and P4 and Q4 are tangent; the test circuit formed by P0 and Q0 is not conductive, the test circuit formed by P1 and Q1 is conductive, the test circuit formed by P2 and Q2 is conductive, the test circuit formed by P3 and Q3 is conductive, and the test circuit formed by P4 and Q4 is not conductive.

[0039] The table below shows the correspondence between the continuity of each test circuit and the alignment deviation in the X-axis direction.

[0040]

[0041] It should be noted that for each test circuit, when the test circuit is conducting, it indicates that the two circular test points that make up the test circuit intersect or coincide; when the test circuit is not conducting, it indicates that the two circular test points that make up the test circuit are tangent or separate.

[0042] For scenario 1 in the table above, the continuity of the test circuits in groups one through five is: non-conducting, conducting, conducting, conducting, non-conducting, respectively. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 4a As shown: P0 is tangent to Q0, P1 intersects Q1, P2 coincides with Q2, P3 intersects Q3, and P4 is tangent to Q4. In this case, the alignment deviation S1 between the first wafer and the second wafer in the X-axis direction is 0, that is, the first wafer and the second wafer are perfectly aligned in the X-axis direction.

[0043] For scenario 2 in the table above, the continuity status of the test circuits from the first to the fifth group is: continuous, continuous, continuous, continuous, non-conductive, respectively. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 4b As shown: P0 intersects Q0, P1 intersects Q1, P2 intersects Q2, P3 intersects Q3, and P4 is separate from Q4. In this case, the alignment deviation between the first wafer and the second wafer in the X-axis direction is 0 < S1 < R.

[0044] For scenario 3 in the table above, the continuity of the test circuits in groups one through five are: continuous, continuous, continuous, non-conductive, and non-conductive, respectively. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 4c As shown: P0 intersects Q0, P1 intersects Q1, P2 intersects Q2, P3 is separate from Q3, and P4 is separate from Q4. In this case, the alignment deviation between the first wafer and the second wafer in the X-axis direction is R ≤ S1 < 2R.

[0045] For scenario 4 in the table above, the continuity of the test circuits in groups one through five are respectively: continuity, continuity, non-conduction, non-conduction, and non-conduction. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 4d As shown: P0 intersects Q0, P1 intersects Q1, P2 is separate from Q2, P3 is separate from Q3, and P4 is separate from Q4. In this case, the alignment deviation between the first wafer and the second wafer in the X-axis direction is 2R ≤ S1 < 3R.

[0046] For case 5 in the table above, the continuity of the test circuits in groups one through five are respectively: continuous, non-conductive, non-conductive, non-conductive, and non-conductive. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 4e As shown: P0 intersects Q0, P1 is separate from Q1, P2 is separate from Q2, P3 is separate from Q3, and P4 is separate from Q4. In this case, the alignment deviation between the first wafer and the second wafer in the X-axis direction is 3R ≤ S1 < 4R.

[0047] For case 6 in the table above, the continuity of the test circuits in groups one through five is: not conducting, not conducting, not conducting, not conducting, not conducting, not conducting. The positional relationship between the circular test points that make up each group of test circuits can be as follows: Figure 4f As shown: P0 is separated from Q0, P1 is separated from Q1, P2 is separated from Q2, P3 is separated from Q3, and P4 is separated from Q4. In this case, the alignment deviation between the first wafer and the second wafer in the X-axis direction is S1≤-3R or S1≥4R.

[0048] Specifically, when determining the bonding alignment deviation between two wafers in the Y-axis direction, we will take as an example five test circuits formed by setting five circular metal test points K0-K4 (shown by solid circles) on the first wafer and five circular metal test points L0-L4 (shown by dashed circles) on the second wafer.

[0049] Under the ideal condition that the first wafer and the second wafer are perfectly aligned in the Y-axis direction after bonding, the test points set in the above manner are: K0 and L0 are tangent, K1 and L1 intersect, K2 and L2 coincide, K3 and L3 intersect, and K4 and L4 are tangent; the test circuit formed by K0 and L0 is not conductive, the test circuit formed by K1 and L1 is conductive, the test circuit formed by K2 and L2 is conductive, the test circuit formed by K3 and L3 is conductive, and the test circuit formed by K4 and L4 is not conductive.

[0050] The table below shows the correspondence between the continuity of each test circuit and the alignment deviation in the Y-axis direction.

[0051]

[0052] It should be noted that for each test circuit, when the test circuit is conducting, it indicates that the two circular test points that make up the test circuit intersect or coincide; when the test circuit is not conducting, it indicates that the two circular test points that make up the test circuit are tangent or separate.

[0053] For scenario 1 in the table above, the continuity of the test circuits in groups one through five is: non-conducting, conducting, conducting, conducting, non-conducting, respectively. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 6a As shown: K0 is tangent to L0, K1 intersects L1, K2 coincides with L2, K3 intersects L3, and K4 is tangent to L4. In this case, the alignment deviation S2 between the first wafer and the second wafer in the Y-axis direction is 0, that is, the first wafer and the second wafer are perfectly aligned in the Y-axis direction.

[0054] For scenario 2 in the table above, the continuity status of the test circuits from the first to the fifth group is: continuous, continuous, continuous, continuous, non-conductive, respectively. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 6b As shown: K0 intersects L0, K1 intersects L1, K2 intersects L2, K3 intersects L3, and K4 is separate from L4. In this case, the alignment deviation between the first wafer and the second wafer in the Y-axis direction is 0 < S2 < R.

[0055] For scenario 3 in the table above, the continuity of the test circuits in groups one through five are: continuous, continuous, continuous, non-conductive, and non-conductive, respectively. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 6c As shown: K0 intersects L0, K1 intersects L1, K2 intersects L2, K3 is separate from L3, and K4 is separate from L4. In this case, the alignment deviation between the first wafer and the second wafer in the Y-axis direction is R ≤ S2 < 2R.

[0056] For scenario 4 in the table above, the continuity of the test circuits in groups one through five are respectively: continuity, continuity, non-conduction, non-conduction, and non-conduction. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 6d As shown: K0 intersects L0, K1 intersects L1, K2 is separate from L2, K3 is separate from L3, and K4 is separate from L4. In this case, the alignment deviation between the first wafer and the second wafer in the Y-axis direction is 2R ≤ S2 < 3R.

[0057] For case 5 in the table above, the continuity of the test circuits in groups one through five are respectively: continuous, non-conductive, non-conductive, non-conductive, and non-conductive. The positional relationship between the circular test points that make up each group of test circuits can be described as follows: Figure 6e As shown: K0 intersects L0, K1 is separate from L1, K2 is separate from L2, K3 is separate from L3, and K4 is separate from L4. In this case, the alignment deviation between the first wafer and the second wafer in the Y-axis direction is 3R≤S2<4R.

[0058] For case 6 in the table above, the continuity of the test circuits in groups one through five is: not conducting, not conducting, not conducting, not conducting, not conducting, not conducting. The positional relationship between the circular test points that make up each group of test circuits can be as follows: Figure 6f As shown: K0 is separated from L0, K1 is separated from L1, K2 is separated from L2, K3 is separated from L3, and K4 is separated from L4. In this case, the alignment deviation between the first wafer and the second wafer in the Y-axis direction is S2≤-3R or S2≥4R.

[0059] S24. Determine the overall bonding alignment deviation between the two wafers based on the bonding alignment deviation between the two wafers in the X-axis direction and the bonding alignment deviation between the two wafers in the Y-axis direction.

[0060] Specifically, based on the bonding alignment deviation between the two wafers in the X-axis direction and the bonding alignment deviation between the two wafers in the Y-axis direction, the range of bonding alignment deviation between the two wafers in the Cartesian coordinate system is determined.

[0061] For example, if the bonding alignment deviation between two wafers in the X-axis direction is R≤S1<2R, and the bonding alignment deviation between two wafers in the Y-axis direction is 0<S2<R, then the bonding alignment deviation range between the two wafers in the Cartesian coordinate system is: the range of offset from R to 2R in the positive X-axis direction, and the range of offset from 0 to R in the positive Y-axis direction, which is the final defined range.

[0062] As can be seen from the above embodiments, the accuracy of detecting wafer bonding alignment deviation depends on the radius R of the circular test point. With the evolution of hybrid bonding technology, the diameter of TSV (Through Silicon Via) can be reduced to below 0.7 μm. Therefore, the detection method provided in this embodiment can improve the accuracy of detecting wafer bonding alignment deviation to above 0.35 μm.

[0063] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method of detecting wafer bonding alignment deviation, the method comprising: The method comprises: a predetermined number of metal test points are arranged on two wafers to be bonded according to predetermined coordinates, respectively, wherein each of the metal test points on the first wafer and each of the metal test points on the second wafer forms a test loop; the conduction of each of the test loops is detected after the two wafers are bonded; the bonding alignment deviation between the two wafers is determined according to the conduction of each of the test loops.

2. The method of claim 1, wherein, The method comprises: a predetermined number of first metal test points for detecting the bonding alignment deviation in the X-axis direction are arranged on the two wafers to be bonded according to predetermined coordinates, respectively, and a predetermined number of second metal test points for detecting the bonding alignment deviation in the Y-axis direction are arranged on the two wafers to be bonded according to predetermined coordinates, respectively; wherein each of the first metal test points on the first wafer and each of the first metal test points on the second wafer forms a test loop, and each of the second metal test points on the first wafer and each of the second metal test points on the second wafer forms a test loop.

3. The method of claim 2, wherein, The method comprises: the bonding alignment deviation between the two wafers in the X-axis direction is determined according to the conduction of each of the test loops formed by each of the first metal test points on the first wafer and each of the first metal test points on the second wafer; the bonding alignment deviation between the two wafers in the Y-axis direction is determined according to the conduction of each of the test loops formed by each of the second metal test points on the first wafer and each of the second metal test points on the second wafer; the overall bonding alignment deviation between the two wafers is determined according to the bonding alignment deviation between the two wafers in the X-axis direction and the bonding alignment deviation between the two wafers in the Y-axis direction.

4. The method of claim 3, wherein, The method comprises: the bonding alignment deviation range between the two wafers in the rectangular coordinate system is determined according to the bonding alignment deviation between the two wafers in the X-axis direction and the bonding alignment deviation between the two wafers in the Y-axis direction.

5. The method of claim 2, wherein, The method comprises: Multiple circular metal test points P0~Pn are set on the first wafer, each with a radius of R, and the coordinates of the center of each test point in the rectangular coordinate system are (X, R, ..., Pn). P0 Y P0 )~(X Pn Y Pn The coordinate relationship between the centers of the test points is X Pn =X Pn-1 +R, Y Pn =Y Pn-1 +a; A plurality of circular metal test points Q0~Qn are arranged on the second wafer, the radius of each test point is R, the coordinates of the center of each test point in the rectangular coordinate system are (X Q0 , Y Q0 )~(X Qn , Y Qn ) respectively, the horizontal coordinates X Q0 of the center of each test point are X Q1 =…=X Qn , and the vertical coordinates Y Q0 of the center of each test point are Y P0 =Y Q1 =Y P1 =Y Qn =Y Pn . wherein X Q0 = X P0 + 2R, n > 1, a > 2R.

6. The method of claim 5, wherein, The test point with the center coordinate (X P0 , Y P0 ) in the first wafer and the test point with the center coordinate (X Q0 , Y Q0 ) in the second wafer are taken as a group of test loops, the test point with the center coordinate (X Pn , Y Pn ) in the first wafer and the test point with the center coordinate (X Qn , Y Qn ) in the second wafer are taken as a group of test loops, and the like.

7. The method of claim 2, wherein, The method comprises: A plurality of circular metal test points K0~Kn are arranged on the first wafer, the radius of each test point is R, the coordinates of the center of each test point in the rectangular coordinate system are (X K0 , Y K0 )~(X Kn , Y Kn ) respectively, and the coordinate relationship between the centers of each test point is Y Kn =Y Kn-1 +R, X Kn =X Kn-1 +b. Multiple circular metal test points L0~Ln are set on the second wafer, each with a radius of R, and the coordinates of the center of each test point in the rectangular coordinate system are (X, R) and (X, R). L0 Y L0 )~(X Ln Y Ln The ordinate Y of the center of each test point L0 =Y L1 =…=Y Ln The x-coordinate of the center of each test point L0 =X K0 X L1 =X K1 , ..., X Ln =X Kn ; where Y L0 = Y K0 + 2R, n≥1, b>2R.

8. The method of claim 7, wherein, The test point with the center coordinate (X K0 , Y K0 ) in the first wafer and the test point with the center coordinate (X L0 , Y L0 ) in the second wafer are taken as a group of test loops, the test point with the center coordinate (X Ln , Y Ln ) in the first wafer and the test point with the center coordinate (X Ln , Y Ln ) in the second wafer are taken as a group of test loops, and the like.

9. The method according to claim 6 or 8, characterized in that, When the test loop formed by the circular metal test point on the first wafer and the circular metal test point on the second wafer is conductive, the circular metal test point on the first wafer intersects or coincides with the circular metal test point on the second wafer; when the test loop formed by the circular metal test point on the first wafer and the circular metal test point on the second wafer is not conductive, the circular metal test point on the first wafer is tangent to or apart from the circular metal test point on the second wafer.

10. The method according to any one of claims 1 to 8, characterized in that, The metal test points and the metal connecting points on both sides of the wafer bonding interface are synchronously manufactured.

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