Apparatus and method for detecting photon emissions from transistors

• US 7,439,730 B2
• Filed: 12/08/2005
• Issued: 10/21/2008
• Est. Priority Date: 09/03/2002
• Status: Expired due to Fees

• Current Assignee: DCG Systems Incorporated (Thermo Fisher Scientific Incorporated)
• Original Assignee: DCG Systems Incorporated (Thermo Fisher Scientific Incorporated)
• Inventors: Kasapi, Steven, Perdu, Philippe, Lo, William K., Desplats, Romain, Le Coupanec, Patricia
• Primary Examiner(s): Nguyen; Ha Tran
• Assistant Examiner(s): Vazquez; Arleen M.
• Application Number:
  US11/296,888
• Publication Number:
  US 20060108997A1
• Time in Patent Office: 1,048 Days
• Field of Search: 324/769, 324/750
• US Class Current: 324/762.08
• CPC Class Codes: G01R 31/2656 using non-ionising electromagnetic radiation, e.g. optical radiation
• CPC Class Codes: G01R 31/311 of integrated circuits G01R31/31728 takes precedence

Abstract

A system, apparatus, and method for analyzing photon emission data to discriminate between photons emitted by transistors and photons emitted by background sources. The analysis involves spatial and/or temporal correlation of photon emissions. After correlation, the analysis may further involve obtaining a likelihood that the correlated photons were emitted by a transistor. After correlation, the analysis may also further involve assigning a weight to individual photon emissions as a function of the correlation. The weight, in some instances, reflecting a likelihood that the photons were emitted by a transistor. The analysis may further involve automatically identifying transistors in a photon emission image.

Claims

1. A method for identifying a transistor by analyzing photon emissions to discriminate between photons emitted from a transistor and noise, the method comprising:

receiving a plurality of photon emissions from an operating integrated circuit including a plurality of transistors;

first processing the plurality of photon emissions such that each photon emission includes a spatial component corresponding with a location on the integrated circuit;

second processing the plurality of photon emissions as a function of the spatial component to identify photon emissions attributable to a particular spatial area of the integrated circuit;

assigning a weight to each photon emission as a function of the operation of second processing; and

providing an indicator on a display identifying at least one particular transistor of the plurality of transistors based on the weight assigned to each photon emission.

2. The method of claim 1 wherein the operation of second processing comprises comparing the spatial component of a first photon emission with the spatial component of at least one subsequent photon emission.

3. The method of claim 2 wherein the spatial component of the first photon emission comprises a first x-value and a first y-value, and wherein the spatial component of the at least one subsequent photon emission comprises at least one subsequent x-value and at least one subsequent y-value.

4. The method of claim 3 wherein the operation of second processing further comprises determining if the first x-value is within a x-range of the at least one subsequent x-value.

5. The method of claim 4 wherein the operation of second processing further comprises determining if the first y-value is within a y-range of the at least one subsequent y-value.

6. The method of claim 5 wherein the operation of assigning a weight to the first photon emission comprises assigning one weight value for each of the at least one subsequent photon emissions having the at least one subsequent x-value within the x-range and, the at least one subsequent y-value within the y range.

7. The method of claim 6 wherein a first threshold is set above which photons emitted are likely attributable to transistor emissions.

8. The method of claim 7 further comprising an operation of sorting through the photon emission data to identify photons having a weight exceeding the first threshold (“

high weight photons”

).

9. The method of claim 8 further comprising defining a subsequent x-range and a subsequent y-range around a high weight photon.

10. The method of claim 9 further comprising determining the number of high weight photons contained within the subsequent x-range and the subsequent y-range.

11. The method of claim 10 wherein the operation of providing comprises identifying a transistor when the number of high weight photons contained within the subsequent x-range and the subsequent y-range exceeds a second threshold.

12. The method of claim 11 wherein the indication identifying at least one particular transistor is a rectangular region around the subsequent x-range and the subsequent y-range.

13. The method of claim 12 further comprising first processing the plurality of photon emissions such that each photon emission includes a spatial component corresponding to a location on the integrated circuit and a temporal component corresponding with the time when each photon emission was detected.

14. The method of claim 13 wherein the operation of second processing further comprises comparing the temporal component of the first photon emission with the temporal component of the at least one subsequent photon emission.

15. The method of claim 14 wherein the temporal component of the first photon emission comprises a first photon emission time value, and wherein the temporal component of subsequent photon emissions comprises a subsequent time value.

16. The method of claim 15 wherein the operation of second processing further comprises determining if the first x-value is within a x-range of the subsequent x-value and the first y-value is within a y-range of the subsequent y-value.

17. The method of claim 16 wherein the operation of second processing further comprises determining if the first time value is within a time-range of the subsequent time value.

18. The method of claim 17 further comprising an operation of assigning a spatial weight to the first photon emission which comprises assigning one spatial weight value for each of the subsequent photon emissions having the at least one second x-value within the x-range and the subsequent y-value within, the y-range.

19. The method of claim 18 further comprising an operation of assigning a temporal weight to the first photon emission which comprises assigning one temporal weight value for each of the at least one second photon emissions having the at least one second time value within the time range.

20. The method of claim 19 wherein a third threshold is set above which photons emitted are likely attributable to transistor emissions.

21. The method of claim 20 wherein an overall weight is a function of the spatial and temporal weights.

22. The method of claim 21 further comprising an operation of sorting through the photon emission data to identify photons having an overall weight exceeding the third threshold (“

emitted photons”

).

23. The method of claim 22 further comprising defining a x-range, a y-range and a time range around an emitted photon.

24. The method of claim 23 further comprising determining the number of emitted photons contained within the defined x-range, y-range and time range.

25. The method of claim 24 wherein the operation of providing comprises identifying a transistor when the number of emitted photons contained within the x-range, y-range and time range exceeds a fourth threshold.

26. The method of claim 24 wherein the indication is a rectangular region around the defined x-range and y-range.