Method of consumer/producer raw material selection

Patent metadata

Field	Value
Publication number	US-9720101-B2
Application number	US-201414242283-A
Country	US
Kind code	B2
Filing date	Apr 1, 2014
Priority date	Jun 27, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

A system, method and computer program product for determining whether a material meets an alpha particle emissivity specification that includes measuring a background alpha particle emissivity for the counter and measuring a combined alpha particle emissivity from the counter containing a sample of the material. The combined alpha particle emissivity includes the background alpha particle emissivity in combination with a sample alpha particle emissivity. The decision statistic is computed based on the observed data and compared to a threshold value. When the decision statistic is less than the threshold value, the material meets the alpha particle emissivity specification. The testing times are computed based on pre-specified criteria so as to meet the needs of both Producer and Consumer.

First claim

What is claimed:

1. A method for determining whether a material meets an alpha particle emissivity specification that comprises:
receiving, at a hardware processor, an alpha particle emissivity specification Λ for a module of emissive material;
calculating, at the hardware processor, a time T b for obtaining a background alpha particle emissivity measurement of a particle counter device used for measuring an alpha particle emissivity for the module; and
iteratively performing:
measuring, at the counter device, a background alpha particle emissivity for the counter device using the time T b for background emissivity measurement;
calculating a time T g for obtaining an alpha particle emissivity measurement of a sample of the module within the counter device using a Poisson based statistical model for alpha particle emissivity, the Poisson based model providing a level of protection for both a consumer and a producer of the module by integrating a consumer specified threshold alpha-particle emissivity that is less than said alpha particle emissivity specification Λ for the module and of a value representative of a producer's risk of module rejection;
measuring, at the counter device, a combined alpha particle emissivity for the counter device containing a sample of the module of emissive material for the time T g for the emissivity measurement of the sample of the module within the counter device;
computing, at the hardware processor, a decision statistic based on said background alpha particle emissivity, the combined alpha particle emissivity and said times T b and T g ;
comparing, at the hardware processor, the decision statistic to the alpha particle emissivity specification Λ; and
deploying, to a consumer, a batch of said emissive material from which said module was taken for use in a product if the decision statistic is less than or equal to the alpha particle emissivity specification Λ, or preventing a deployment to the consumer of the batch of said emissive material from which said module was taken if the decision statistic exceeds the alpha particle emissivity specification Λ.

2. The method of claim 1 , where the decision statistic is the upper (1−α)*100% confidence bound for an alpha-particle emissivity of module λ.

3. The method of claim 1 , where the decision statistic is evidence that the alpha-particle emissivity of module is unacceptable computed based on a statistical likelihood ratio test.

4. The method of claim 1 , wherein the threshold alpha-particle emissivity includes a pre-specified consumer-protected alpha particle emissivity λ 0 that is below the alpha particle emissivity specification for the module.

5. The method of claim 1 , wherein said calculating the time T b for background emissivity measurement for the counter device and the time T g for the emissivity measurement of the sample within the counter device using the Poisson based statistical model includes imputing at least an estimated background, b 0 emissivity and the alpha particle emissivity specification into the Poisson based statistical model.

6. The method of claim 1 , wherein the pre-specified consumer-protected alpha particle emissivity λ 0 is a value for which the probability of module acceptance is (1−γ)*100%, where γ is a value representing a producer's risk.

7. A computer program product for determining whether a material meets an alpha particle emissivity specification, the computer program product comprising a non-transitory computer readable storage medium, said non-transitory medium tangibly embodying a program of instructions executable by the computer for:
receiving an alpha particle emissivity specification Λ for a module of emissive material;
calculating a time T b for obtaining a background alpha particle emissivity measurement of a particle counter device used for measuring an alpha particle emissivity for the module; and
iteratively performing:
measuring, at the counter device, a background alpha particle emissivity for the counter device using the time T b for background emissivity measurement;
calculating a time T g for obtaining an alpha particle emissivity measurement of a sample of the module within the counter device using a Poisson based statistical model for alpha particle emissivity, the Poisson based model providing a level of protection for both a consumer and a producer of the module by integrating a consumer specified threshold alpha-particle emissivity that is less than said alpha particle emissivity specification Λ for the module and of a value representative of a producer's risk of module rejection;

measuring, at the counter device, a combined alpha particle emissivity from the counter device containing the sample of the emissive material for the time T g for the emissivity measurement of the sample of the module within the counter device,
computing a decision statistic based on said background alpha particle emissivity, the combined alpha particle emissivity and said times T b and Tg;
comparing the decision statistic to the alpha particle emissivity specification Λ; and
deploying, to a consumer, a batch of said emissive material from which said module was taken for use in a product if the decision statistic is less than or equal to the alpha particle emissivity specification Λ, or preventing a deployment to the consumer of the batch of said emissive material from which said module was taken if the decision statistic exceeds the alpha particle emissivity specification Λ.

8. The computer program product of claim 7 , where the decision statistic is the upper (1−α)*100% confidence bound for an alpha-particle emissivity of module λ.

9. The computer program product of claim 7 , where the decision statistic is evidence that the alpha-particle emissivity of module is unacceptable computed based on a statistical likelihood ratio test.

10. The computer program product of claim 7 , wherein the threshold alpha-particle emissivity includes a pre-specified consumer-protected alpha particle emissivity λ 0 that is below the alpha particle emissivity specification for the module.

11. The computer program product of claim 7 , wherein said calculating the time T b for background emissivity measurement for the counter device and the time T g for the emissivity measurement of the sample within the counter device using the Poisson based statistical model includes imputing at least an estimated background, b 0 emissivity and the alpha particle emissivity specification into the Poisson based statistical model.

12. The computer program product of claim 7 , wherein the pre-specified consumer-protected alpha particle emissivity λ 0 is a value for which the probability of module acceptance is (1−γ)*100%, where γ is a value representing a producer's risk.

13. A system for indicating whether a material meets an alpha particle emissivity specification comprising:
a memory storage device;
a hardware processor in communication with said memory storage device and configured to:
receive an alpha particle emissivity specification Λ for a module of emissive material;
calculate a time T b for obtaining a background alpha particle emissivity measurement of a particle counter device used for measuring an alpha particle emissivity for the module; and an iterative process to:
measure, at the counter device, a background alpha particle emissivity for the counter device using the time T b for background emissivity measurement;
calculate a time T g for obtaining an alpha particle emissivity measurement of a sample of the module within the counter device using a Poisson based statistical model for alpha particle emissivity, the Poisson based mod

Assignees

• Globalfoundries Inc

Inventors

• Gordon Michael S
• Rodbell Kenneth P
• Yashchin Emmanuel

Classifications

• G01T1/178 Primary

  for measuring specific activity in the presence of other radioactive substances, e.g. natural, in the air or in liquids such as rain water · CPC title

• H01L2924/00

  Electricity · mapped topic

• H01L2924/0002

  Electricity · mapped topic