APPARATUS AND METHOD FOR DETECTING PHOTON EMISSIONS FROM TRANSISTORS

• US 20060181268A1
• Filed: 04/25/2006
• Published: 08/17/2006
• Est. Priority Date: 09/03/2002
• Status: Active Grant

• Current Assignee: DCG Systems Incorporated (Thermo Fisher Scientific Incorporated)
• Original Assignee: Credence Systems Corporation (COHU Incorporated)
• Inventors: Kasapi, Steven, Perdu, Philippe, Lo, William K., Desplats, Romain, Le Coupanec, Patricia
• Granted Patent: US 7,323,862 B2
• Time in Patent Office: Days
• US Class Current: 324/762.90
• 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 analyzing photon emissions collected from a transistor to discriminate between photons emitted from a transistor and photons emitted from other sources, the collected photon emissions comprising a spatial component and a temporal component corresponding with the space where each photon was detected and the time when each photon was detected, the method comprising:

spatially correlating the collected photon emissions data;

temporally correlating the collected photon emission data; and

determining a likelihood that all or a portion of the spatially correlated photon emission data originated from a transistor photon emission.

2. The method of claim 1 wherein the operation of spatially correlating the collected photon emission data comprises obtaining a first grouping of spatially similar photon emissions from the collected photon emission data.

3. The method of claim 1 wherein the collected photon emission data comprises at least a first photon emission having a first spatial component and a first temporal component and at least a second photon emission having a second spatial component and a second temporal component, the operation of spatially correlating the collected photon emission data comprises determining if the first spatial component is within a spatial range of the second spatial component.

4. The method of claim 2 wherein the operation of temporally correlating the collected photon emission data comprises obtaining a second grouping of temporally similar photon emissions from the first grouping.

5. The method of claim 3 wherein the operation of temporally correlating the collected photon emission data comprises determining if the first temporal component is within a temporal range of the second temporal component.

6. The method of claim 2 wherein the operation of obtaining a first grouping of spatially similar photon emissions comprises:

receiving an indication of a spatial range;

identifying a first photon with a first spatial component within the spatial range;

analyzing the collected photon emission data to identify a number of photons within the spatial range about the first photon; and

including the number of photons within the spatial range in the first grouping when the number of photons meets a threshold.

7. The method of claim 6 wherein the first spatial component comprises a x-value and a y-value and the spatial range comprises a x-range and a y-range.

8. The method of claim 7 wherein the spatial range about the first photon comprises a rectangular region defined by:

(x-value−

x-range/2, x-value+x-range/2), (y-value−

y-range/2, y-value+y-range/2).

9. The method of claim 2 wherein the operation of obtaining a first grouping of spatially similar photon emissions comprises:

receiving an indication of a spatial and temporal range;

identifying a first photon with a first spatial and temporal component within the spatial and temporal range;

analyzing the collected photon emission data to identify a number of photons within the spatial and temporal range about the first photon; and

including the number of photons within the spatial and temporal range in the first grouping when the number of photons meets a second threshold.

10. The method of claim 9 wherein the first spatial and temporal component comprises a x-value, a y-value and a time value, the spatial and temporal range comprises a x-range, a y-range, and a time range.

11. The method of claim 10 wherein the spatial and temporal range about the photon comprises a brick shaped region defined by:

(x-value−

x-range/2, x-value+x-range/2), (y-value−

y-range/2, y-value+y-range/2), (time value−

time range/2, time value+time range/2).

12. A picosecond imaging circuit analysis probe system configured to perform the method of claim 1.