Mapping yield information of semiconductor dice

• US 7,440,869 B1
• Filed: 05/26/2004
• Issued: 10/21/2008
• Est. Priority Date: 05/26/2004
• Status: Active Grant

• Current Assignee: PDF Solutions
• Original Assignee: PDF Solutions
• Inventors: Cadouri, Eitan
• Primary Examiner(s): Raymond; Edward
• Application Number:
  US10/854,970
• Time in Patent Office: 1,609 Days
• Field of Search: 702/179, 702/59, 702/117, 702/118, 702182-185, 702/188, 324/512, 438/10, 438/12, 438/5, 438/17, 438/18
• US Class Current: 702/179
• CPC Class Codes: H01L 22/20 Sequence of activities consisting of a plurality of measurements, corrections, marking or sorting steps

Abstract

In one exemplary embodiment, yield information of semiconductor dice is mapped by obtaining yield information of a first die that was formed on a first location on a first wafer. Yield information is obtained of a second die that was formed on a second location on a second wafer. A portion of the first location corresponds to a portion of the second location such that the portion of the first location would overlap with the portion of the second location if the first location was on the second wafer. A plurality of pixel elements is defined. Each pixel element corresponds to a different location on a wafer, and at least one of the plurality of pixel elements corresponds to the portion of the first location that corresponds to the portion of the second location. An average yield is determined for the at least one of the plurality of pixel elements based on the yield information of the first die and the second die. A deviation is determined for the at least one of the plurality of pixel elements based on the average yield of the at least one of the plurality of pixel elements and the yield information of the first die and the second die.

Claims

1. A method of mapping yield information of semiconductor dice, the method comprising:

obtaining yield information of a first die that was formed on a first location on a first wafer in accordance with a first die placement;

obtaining yield information of a second die that was formed on a second location on a second wafer in accordance with a second die placement,

wherein the first die placement and the second die placement have different layouts;

wherein a portion of the first location corresponds to a portion of the second location such that the portion of the first location would overlap with the portion of the second location if the first location was on the second wafer;

defining a plurality of pixel elements, wherein each pixel element corresponds to a different location on a wafer, and wherein at least one of the plurality of pixel elements corresponds to the portion of the first location that corresponds to the portion of the second location;

determining an average yield for the at least one of the plurality of pixel elements based on the yield information of the first die and the second die; and

determining a deviation for the at least one of the plurality of pixel elements based on the average yield of the at least one of the plurality of pixel elements and the yield information of the first die and the second die.

2. The method of claim 1, wherein the first die and the second die are different products produced by the same process.

3. The method of claim 1, further comprising:

obtaining yield information of a first set of dice formed on locations on the first wafer;

obtaining yield information of a second set of dice formed on locations on the second wafer,

wherein locations on the first wafer correspond with locations on the second wafer such that locations on the first wafer would overlap with locations on the second wafer if the locations on the first wafer were on the second wafer, and

wherein the plurality of pixel elements correspond to the overlapping locations;

determining an average yield for each of the plurality of pixel elements based on the yield information of the first set of dice and the second set of dice; and

determining a deviation for each of the plurality of pixel elements based on the average yield of each of the plurality of pixel elements and the yield information of the first set of dice and the second set of dice.

4. The method of claim 3, further comprising:

obtaining yield information of a plurality of additional sets of dice formed on locations on a plurality of additional wafers,

wherein the locations on the plurality of additional wafers overlap, and

wherein the plurality of pixel elements correspond to the overlapping locations;

determining an average yield for each of the plurality of pixel elements based on the yield information of the plurality of additional sets of dice; and

determining a deviation for each of the plurality of pixel elements based on the average yield of each of the plurality of pixel elements and the yield information of the plurality of additional sets of dice.

5. The method of claim 4, wherein the average yield for a pixel element is determined as a sum of the yield information of all the dice in a location corresponding to the pixel element divided by the number of dice in the location, and wherein the deviation for the pixel element is determined as a percentage of deviation of the yield information of all the dice in the location.

6. The method of claim 3, further comprising:

identifying a location of interest; and

grouping pixel elements around the location of interest based on the average yield and deviation of the pixel elements.

7. The method of claim 6, wherein grouping pixel elements around the location of interest is ceased when the average yield or the deviation of the pixel elements is greater than an established limit.

8. The method of claim 6, wherein the location of interest corresponds to a location on a wafer that interacts with a processing equipment used to process the wafer.

9. The method of claim 8, wherein the processing equipment includes a clamp, wafer scribe, wafer identification, or nitride injector.

10. The method of claim 6, further comprising:

determining a third die placement based on the plurality of pixel elements.

11. The method of claim 10, further comprising:

determining a predicted yield of a die in the third die placement based on the average yields and deviations of the plurality of pixel elements.

12. The method of claim 11, further comprising:

determining the predicted yield of the die based on the average yield and deviation of one or more pixel elements corresponding to the location of the die.

13. The method of claim 12, further comprising:

when the location of the die corresponds to two or more pixel elements, selecting the yield of the pixel element with the lowest deviation.

14. The method of claim 13, further comprising:

when the location of the die corresponds to two or more pixel elements and the deviations of the two or more pixel elements are the same or within a determined range, averaging the yields of the two or more pixel elements to determine the predicted yield of the die.

15. The method of claim 1, further comprising:

normalizing the yield information of the first die and the second die, wherein the average yield and the deviation for the at least one of the plurality of pixel elements are determined based on the normalized yield information of the first die and the second die.

16. The method of claim 15, wherein the yield information of the first die and the second die are normalized using a linear function that takes into account average yield.

17. A method of mapping yield information of semiconductor dice, the method comprising:

obtaining yield information of a first set of dice that was formed on a first set of locations on a first set of wafers in accordance with a first die placement;

obtaining yield information of a second set of dice that was formed on a second set of locations on a second set of wafers in accordance with a second die placement,

wherein the first die placement and the second die placement have different layouts;

wherein a portion of the first set of locations corresponds to a portion of the second set of locations such that the portion of the first set of locations would overlap with the portion of the second set of locations if the first set of locations was on the second set of wafers;

defining a plurality of pixel elements, wherein each pixel element corresponds to a different location on a wafer, and wherein the plurality of pixel elements corresponds to the portion of the first set of locations that corresponds to the portion of the second set of locations;

determining an average yield for each of the plurality of pixel elements based on the yield information of the first set of dice and the second set of dice; and

determining a deviation for each of the plurality of pixel elements based on the average yield of each of the plurality of pixel elements and the yield information of the first set of dice and the second set of dice.

18. The method of claim 17, wherein the first set of dice and the second set of dice are different products produced by the same process.

19. The method of claim 17, wherein the average yield for a pixel element is determined as a sum of the yield information of all the dice in a location corresponding to the pixel element divided by the number of dice in the location, and wherein the deviation for the pixel element is determined as a percentage of deviation of the yield information of all the dice in the location.

20. The method of claim 17, further comprising:

identifying a location of interest; and

grouping pixel elements around the location of interest based on the average yield and deviation of the pixel elements.

21. The method of claim 20, wherein grouping pixel elements around the location of interest is ceased when the average yield or the deviation of the pixel elements is greater than an established limit.

22. The method of claim 20, wherein the location of interest corresponds to a location on a wafer that interacts with a processing equipment used to process the wafer.

23. The method of claim 22, wherein the processing equipment includes a clamp, wafer scribe, wafer identification, or nitride injector.

24. The method of claim 20, further comprising:

determining a third die placement based on the plurality of pixel elements.

25. The method of claim 24, further comprising:

determining a predicted yield of a die in the third die placement based on the average yields and deviations of the plurality of pixel elements.

26. The method of claim 25, further comprising:

determining the predicted yield of the die based on the average yield and deviation of one or more pixel elements corresponding to the location of the die.

27. The method of claim 26, further comprising:

when the location of the die corresponds to two or more pixel elements, selecting the yield of the pixel element with the lowest deviation.

28. The method of claim 26, further comprising:

when the location of the die corresponds to two or more pixel elements and the deviations of the two or more pixel elements are the same or within a determined range, averaging the yields of the two or more pixel elements to determine the predicted yield of the die.

29. The method of claim 17, further comprising:

normalizing the yield information of the first set of dice and the second set of dice, wherein the average yield and the deviation for each of the plurality of pixel elements are determined based on the normalized yield information of the first set of dice and the second set of dice.

30. The method of claim 29, wherein the yield information of the first set of dice and the second set of dice are normalized using a linear function that takes into account average yield.

31. A map of yield information of semiconductor dice, the map comprising:

a plurality of pixel elements, wherein each pixel element corresponds to a different location on a wafer, and wherein the plurality of pixel elements corresponds to a portion of a first set of locations on a first set of wafers that corresponds to a portion of a second set of locations on a second set of wafers such that the portion of the first set of locations would overlap with the portion of the second set of locations if the first set of locations was on the second set of wafers;

an average yield associated with each of the plurality of pixel elements, wherein the average yield is determined based on yield information of a first set of dice that was formed on the first set of locations on the first set of wafers in accordance with a first die placement and a second set of dice that was formed on the second set of locations on the second set of wafers in accordance with a second die placement, wherein the first die placement and the second die placement have different layouts; and

a deviation associated with each of the plurality of pixel elements, wherein the deviation is determined based on the average yield of each of the plurality of pixel elements and the yield information of the first set of dice and the second set of dice, wherein the first set of dice and the second set of dice have different placements.

32. The map of claim 31, wherein the first set of dice and the second set of dice are different products produced by the same process.

33. The map of claim 31, wherein the average yield for each of the plurality of pixel elements is determined as a sum of the yield information of all the dice in a location corresponding to the pixel element divided by the number of dice in the location, and wherein the deviation for the pixel element is determined as a percentage of deviation of the yield information of all the dice in the location.

34. The map of claim 31, further comprising:

a location of interest; and

a grouping of pixel elements around the location of interest, wherein the grouping is determined based on the average yield and deviation of the pixel elements.

35. The map of claim 34, wherein the grouping of pixel elements around the location of interest is ceased when the average yield or the deviation of the pixel elements is greater than an established limit.

36. The map of claim 34, wherein the location of interest corresponds to a location on a wafer that interacts with a processing equipment used to process the wafer.

37. The map of claim 36, wherein the processing equipment includes a clamp, wafer scribe, wafer identification, or nitride injector.

38. The map of claim 31, further comprising:

a third die placement determined based on the plurality of pixel elements.

39. The map of claim 38, further comprising:

a predicted yield associated with a die in the third die placement, the predicted yield determined based on the average yields and deviations of the plurality of pixel elements.

40. The map of claim 39, wherein the predicted yield of the die is determined based on the average yield and deviation of one or more pixel elements corresponding to the location of the die.

41. The map of claim 40, wherein when the location of the die corresponds to two or more pixel elements, the yield of the pixel element with the lowest deviation is selected as the predicted yield of the die.

42. The method of claim 41, wherein when the location of the die corresponds to two or more pixel elements and the deviations of the two or more pixel elements are the same or within a determined range, an average of the yields of the two or more pixel elements is selected as the predicted yield of the die.

43. The map of claim 31, wherein the average yield and the deviation for the at least one of the plurality of pixel elements are determined based on normalized yield information of the first set of dice and the second set of dice.

44. The map of claim 43, wherein the normalized yield information of the first set of dice and the second set of dice comprises actual yields of the first set of dice and the second of dice divided by average yields of the first set of dice and the second set of dice.

45. The map of claim 44, wherein the normalized yield information of the first set of dice and the second set of dice are normalized using a linear or nonlinear function that takes into account average yield.