Adaptive Test Sequence for Testing Integrated Circuits

• US 20120246514A1
• Filed: 03/25/2011
• Published: 09/27/2012
• Est. Priority Date: 03/25/2011
• Status: Active Grant

• Current Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Original Assignee: Taiwan Semiconductor Manufacturing Company Limited
• Inventors: Lin, Hung-Chih, Wang, Mill-Jer, Chen, Hao, Chen, Chun-Cheng, Peng, Ching-Nen
• Granted Patent: US 9,310,437 B2
• Time in Patent Office: Days
• US Class Current: 714/32
• CPC Class Codes: G01R 31/318371 Methodologies therefor, e.g. algorithms, procedures
• CPC Class Codes: G01R 31/318511 Wafer Test
• CPC Class Codes: G01R 31/31919 Storing and outputting test patterns G01R31/31924 takes precedence; arithmetic and random test patterns generator

Abstract

A method includes testing a first device and a second device identical to each other and comprising integrated circuits. The testing of the first device is performed according to a first test sequence of the first device, wherein the first test sequence includes a plurality of ordered test items, and wherein the first test sequence includes a test item. A test priority of the test item is calculated based on a frequency of fails of the test item in the testing of a plurality of devices having an identical structure as the first device. The first test sequence is then adjusted to generate a second test sequence in response to the test priority of the test item, wherein the second test sequence is different from the first test sequence. The second device is tested according to the second test sequence.

Claims

1. A method comprising:

testing a first device comprising integrated circuits according to a first test sequence of the first device, wherein the first test sequence comprises a plurality of ordered test items, and wherein the first test sequence comprises a first test item;

calculating a test priority of the first test item based on a frequency of fails of the first test item in the testing of a plurality of devices having an identical structure as the first device;

adjusting the first test sequence to generate a second test sequence in response to the test priority of the first test item, wherein the second test sequence is different from the first test sequence; and

testing a second device identical to the first device according to the second test sequence.

2. The method of claim 1, wherein the first test item in the second test sequence is in a position ahead of a position of the first test item in the first test sequence.

3. The method of claim 1, wherein the first test item in the second test sequence is not a top test item.

4. The method of claim 1, wherein the step of calculating the test priority of the first test item comprises assigning a first and a second weight to the first test item and a second test item, respectively, in the first test sequence, wherein the first weight is different from the second weight.

5. The method of claim 1, wherein the test priority of the first test item is calculated by dividing a count of all devices failed on the first item by a total count of all tested devices, wherein the all tested devices are identical to the first device.

6. The method of claim 1, wherein the test priority of the first test item is calculated by dividing a count of all recent dies failed on the first test item by a total count of a plurality of most recently tested devices, wherein the all recent dies failed on the first test item are within the plurality of most recently tested devices.

7. The method of claim 1 further comprising:

after finishing testing the first test item, measuring a parameter selected from the group consisting of a temperature of the first device, a stress of the first device, and combinations thereof;

adjusting the first test sequence to generate a third test sequence in response to a value of the parameter, wherein the third test sequence is different from the first test sequence; and

executing remaining test items in the first test sequence on the first device according to the third test sequence.

8. The method of claim 1, wherein the first test item is a test chain comprising a plurality of test items having a fixed test sequence.

9. A method comprising:

testing a first device according to a first test sequence, wherein the step of testing the first device comprises;

executing a first test item in the first test sequence; and

after the step of executing the first test item, executing a second test item in the first test sequence, wherein the second test item fails; and

after the step of testing the first device, testing a second device identical to the first device according to a second test sequence different from the first test sequence, wherein the step of testing the second device comprises;

executing a top test item in second test sequence;

after the step of executing the top test item, executing the second test item in the second test sequence; and

after the step of executing the second test item, executing the first test item.

10. The method of claim 9, wherein the step of executing the first test item for the second device fails, and wherein the method further comprises:

after the step of testing the second device, testing a third device identical to the first device according to the second test sequence.

11. The method of claim 9 further comprising:

calculating test priorities of the first and the second test items based on frequencies of fails of the first and the second test items in the testing of a plurality of devices having an identical structure as the first device; and

adjusting the first test sequence to generate the second test sequence in response to the test priorities of the first and the second test items.

12. The method of claim 11, wherein the step of calculating the test priorities of the first and the second test items comprises assigning a first and a second weight to the first and the second test items, respectively, and wherein the first weight is different from the second weight.

13. The method of claim 11, wherein the test priority of the first test item is calculated by dividing a count of all dies failed on the first test item by a total count of all tested devices, wherein the all tested devices are identical to the first device.

14. The method of claim 11, wherein a test priority of the first test item is calculated by dividing a count of recent dies failed on the first item by a total count of a plurality of most recently tested devices, wherein the recent dies failed on the first test item are within the plurality of most recently tested devices, and wherein all tested devices are identical to the first device.

15. The method of claim 9 further comprising:

after finishing executing the first test item for the second device, measuring a parameter selected from the group consisting of a temperature of the second device, a stress of the second device, and combinations thereof;

adjusting the second test sequence to generate a third test sequence in response to the parameter, wherein the third test sequence is different from the second test sequence; and

finishing testing the second device according to the third test sequence.

16. A method comprising:

testing a device according to a first test sequence, wherein the step of testing the device comprises;

executing a first test item in the first test sequence; and

after finishing executing the first test item, measuring a parameter selected from the group consisting of a temperature of the device, a stress of the device, and combinations thereof;

adjusting the first test sequence to generate a second test sequence in response to the parameter, wherein the second test sequence is different from the first test sequence; and

executing remaining test items in the first test sequence according to an order of the second test sequence.

17. The method of claim 16 further comprising:

after the steps of testing the device and executing the remaining test items, testing an additional device identical to the device using the second test sequence.

18. The method of claim 16 further comprising, after the step of executing the remaining test items, further adjusting the second test sequence to generate a third test sequence according to a failed test item of the device, wherein the third test sequence is different from the second test sequence.

19. The method of claim 18, wherein the step of adjusting the second test sequence to generate the third test sequence comprises:

determining test priorities of test items in the second test sequence based on failure frequencies of the test items; and

ordering the test items in the second test sequence according to the test priorities of the test items to generate the third test sequence.

20. The method of claim 19, wherein the step of determining the test priorities of the test items is performed by assigning different weights to different ones of the test items.