Method for improving through hole test accuracy

Abstract

The invention discloses a method for improving the accuracy of a through hole test, and the method comprises the steps: setting a test key position region on a cutting channel, the test key position region comprises a first position region, a second position region and a third position region, and the length directions of the first position region, the second position region and the third position region are parallel to the length direction of the corresponding cutting channel and are arranged along the width direction of the cutting channel. A through hole test key is arranged in the first position area, a fixed second test key is arranged in the second position area, a selected third test key is arranged in the third position area, and the third test key is adjusted according to metal wire options. And performing an inline WAT test, namely testing the corresponding metal wire by adopting a third test key, and preventing the inline WAT test from generating adverse effects on the through hole test key by utilizing the characteristic that a second position area is spaced between the first position area and the third position area. And performing a final WAT test, including performing a through hole test by using a through hole test key. According to the invention, the inline WAT test of the metal wire can be prevented from generating adverse effects on the through hole test key, so that the through hole test accuracy can be improved.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a semiconductor integrated circuit, and in particular to a method for improving the accuracy of through-hole testing. Background Art

[0002] In some process products, the electrical parameter V3_RCVC of the resistance and capacitance (RC) of the third-layer through hole (V3) may shift in the final WAT due to the compressive stress or deformation caused by needle insertion during the inline wafer acceptance test (WAT) of the third-layer metal line (M3).

[0003] Among them, inline WAT will be carried out during the wafer manufacturing process, and final WAT will be carried out after the wafer manufacturing is completed. The V3RC test, that is, the test of the third-layer through-hole, is carried out in the final WAT. The M3 test is carried out in the inline WAT, so the M3 test will be carried out before the V3RC test. Therefore, after the M3 test is completed, since the top of V3 is connected to the corresponding M3, the needle on M3 is likely to cause stress or deformation to V3, which ultimately affects the V3 test. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method for improving the accuracy of through-hole testing, which can prevent the inline WAT test of the metal wire from having an adverse effect on the through-hole test key, thereby improving the accuracy of the through-hole testing.

[0005] In order to solve the above technical problems, the method for improving the accuracy of through-hole testing provided by the present invention comprises the following steps:

[0006] A test key (TSK) position area is set on the cutting road, and the test key position area includes a first position area, a second position area and a third position area. The length directions of the first position area, the second position area and the third position area are parallel to the length direction of the corresponding cutting road. The first position area, the second position area and the third position area are arranged along the width direction of the cutting road, and the second position area is located between the first position area and the third position area.

[0007] A through-hole test key is set in the first position area, a fixed second test key is set in the second position area, and a selected third test key is set in the third position area, and the third test key is adjusted according to the metal line option.

[0008] An inline WAT test is performed during the wafer manufacturing process, wherein the inline WAT test includes using the third test key to test the corresponding metal wire, and utilizing the feature that the second position area is spaced between the first position area and the third position area to prevent the inline WAT test from having an adverse effect on the through-hole test key.

[0009] After wafer manufacturing is completed, a final WAT test is performed, and the final WAT test includes performing a through-hole test using the through-hole test key.

[0010] A further improvement is that the through-hole test key is a third-layer through-hole test key, and the through-hole test is a third-layer through-hole test.

[0011] A further improvement is that the final WAT test also includes testing using the second test key.

[0012] A further improvement is that the second test key includes: an RDL test key, an M6 test key, and a UTM test key; RDL is a redistribution layer, M6 is a sixth layer of metal wire, and UTM is a top metal layer.

[0013] A further improvement is that the third test key includes a plurality of selectable test keys, and each layer of the metal wire selects one from the plurality of selectable test keys as the corresponding third test key as required.

[0014] A further improvement is that the layers of the metal wire corresponding to the third test key include a first layer, a second layer, an eighth layer and a tenth layer.

[0015] A further improvement is that, in the width direction along the cutting path, the width edges of the first position area, the second position area and the third position area are aligned.

[0016] The present invention makes special arrangements for the placement rules of the test keys, and sets the test key position areas to three, wherein a fixed through-hole test key is set in the first position area, a fixed second test key is set in the second position area, and a third test key related to a metal wire option is set in the third position area. In the inline WAT test, only the third test key will be subjected to a needle-piercing test. Since the first position area and the third position area are separated by the second position area, this non-adjacent arrangement can ensure that the inline WAT test of the metal wire will not have an adverse effect on the through-hole test key, thereby improving the through-hole test accuracy in the final WAT test. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments:

[0018] Figure 1 is a flow chart of a method for improving through-hole test accuracy according to an embodiment of the present invention;

[0019] Figure 2 It is a structural schematic diagram of the test key position area in the method for improving through-hole test accuracy in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] like Figure 1 As shown in FIG. 1 , it is a flow chart of a method for improving through-hole test accuracy according to an embodiment of the present invention; Figure 2 , which is a schematic diagram of the structure of the test key position area in the method for improving the through-hole test accuracy according to an embodiment of the present invention; the method for improving the through-hole test accuracy according to an embodiment of the present invention comprises the following steps:

[0021] Step S101: Figure 2 As shown, a test key position area is set on the cutting road 102, and the cutting road 102 is located between each main chip 101. The test key position area includes a first position area 103a, a second position area 103b and a third position area 103c, and the length directions of the first position area 103a, the second position area 103b and the third position area 103c are parallel to the length direction of the corresponding cutting road 102, and the first position area 103a, the second position area 103b and the third position area 103c are arranged along the width direction of the cutting road 102, and the second position area 103b is located between the first position area 103a and the third position area 103c.

[0022] In the embodiment of the present invention, along the width direction of the cutting street 102 , the width edges of the first position area 103 a , the second position area 103 b and the third position area 103 c are aligned.

[0023] Step S102, setting a through-hole test key in the first position area 103a, setting a fixed second test key in the second position area 103b, and setting a selected third test key in the third position area 103c, wherein the third test key is adjusted according to the metal wire option.

[0024] In the embodiment of the present invention, the through hole test key is a third-layer through hole test key.

[0025] The second test key includes: an RDL test key, an M6 test key, and a UTM test key; RDL is a redistribution layer, M6 is a sixth layer of metal wire, and UTM is a top metal layer.

[0026] The through-hole test key and the second test key are both fixed test keys and only need to be tested in the final WAT.

[0027] The third test key is an adjustable test key and needs to be tested in the inline WAT, so the metal wires at different layers need to be provided with corresponding third test keys. In some embodiments, the third test key includes multiple selectable test keys, and the metal wires at each layer select one of the multiple selectable test keys as the corresponding third test key as needed.

[0028] The layers of the metal wire corresponding to the third test key include a first layer, a second layer, an eighth layer and a tenth layer.

[0029] Step S103, performing an inline WAT test during the wafer manufacturing process, wherein the inline WAT test includes using the third test key to test the corresponding metal wire, and utilizing the feature that the second position area 103b is spaced between the first position area 103a and the third position area 103c to prevent the inline WAT test from having an adverse effect on the through-hole test key.

[0030] Step S104: performing a final WAT test after wafer manufacturing is completed, wherein the final WAT test includes performing a through-hole test using the through-hole test key.

[0031] In the embodiment of the present invention, the via test is a third-layer via test, namely, a V3RC test.

[0032] The final WAT test also includes using the second test key to perform testing.

[0033] The embodiment of the present invention makes special arrangements for the placement rules of the test keys, and sets the number of test key position areas to three, wherein a fixed through-hole test key is set in the first position area 103a, a fixed second test key is set in the second position area 103b, and a third test key related to the metal wire option is set in the third position area 103c. In the inline WAT test, only the third test key will be subjected to a needle test. Since the first position area 103a and the third position area 103c are separated by the second position area 103b, this non-adjacent arrangement can ensure that the inline WAT test of the metal wire will not have an adverse effect on the through-hole test key, thereby improving the through-hole test accuracy in the final WAT test.

[0034] In the embodiment of the present invention, the TSK placement rule is optimized to improve the test accuracy of V3RC;

[0035] In the prior art, the inline WAT test will lead to inaccurate Final WAT test. The embodiment of the present invention can improve the accuracy of V3RC test by adjusting the TSK placement rule. After verification, the final WAT test problem of V3RC can be solved, and the adverse impact ratio (suffer ratio) is about 0%.

[0036] The present invention has been described in detail above through specific embodiments, but these do not constitute limitations of the present invention. Without departing from the principle of the present invention, those skilled in the art may also make many variations and improvements, which should also be considered as the protection scope of the present invention.

Claims

1. A method for improving through-hole testing accuracy, characterized in that: The steps include: A test key position area is set on the cutting road, the test key position area includes a first position area, a second position area and a third position area, the length directions of the first position area, the second position area and the third position area are parallel to the length direction of the corresponding cutting road, the first position area, the second position area and the third position area are arranged along the width direction of the cutting road, and the second position area is located between the first position area and the third position area; A through-hole test key is arranged in the first position area, a fixed second test key is arranged in the second position area, and a selected third test key is arranged in the third position area, wherein the third test key is adjusted according to the metal wire option; Performing an inline WAT test during wafer manufacturing, wherein the inline WAT test includes using the third test key to test the corresponding metal wire, and utilizing the feature that the second position area is spaced between the first position area and the third position area to prevent the inline WAT test from having an adverse effect on the through-hole test key; After wafer manufacturing is completed, a final WAT test is performed, and the final WAT test includes performing a through-hole test using the through-hole test key.

2. The method for improving through-hole testing accuracy according to claim 1, wherein: The through-hole test key is a third-layer through-hole test key, and the through-hole test is a third-layer through-hole test.

3. The method for improving through-hole testing accuracy according to claim 1, wherein: The finalWAT test also includes testing using the second test key.

4. The method for improving through-hole testing accuracy as claimed in claim 3, characterized in that: The second test key includes: an RDL test key, an M6 test key, and a UTM test key; RDL is a redistribution layer, M6 is a sixth layer of metal wire, and UTM is a top metal layer.

5. The method for improving through-hole testing accuracy according to claim 1, wherein: The third test key includes a plurality of selectable test keys, and each layer of the metal wire selects one from the plurality of selectable test keys as the corresponding third test key as required.

6. The method for improving through-hole testing accuracy as claimed in claim 5, characterized in that: The layers of the metal wire corresponding to the third test key include a first layer, a second layer, an eighth layer and a tenth layer.

7. The method for improving through-hole testing accuracy as claimed in claim 1, characterized in that: In the width direction along the cutting street, the width sides of the first position area, the second position area and the third position area are aligned.

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