Methods and systems for semiconductor diode junction protection

• US 7,684,960 B1
• Filed: 10/18/2007
• Issued: 03/23/2010
• Est. Priority Date: 10/18/2006
• Status: Expired due to Fees

• Current Assignee: Science Research Laboratory, Inc.
• Original Assignee: Science Research Laboratory, Inc.
• Inventors: Jacob, Jonah H.
• Primary Examiner(s): TSAI, CAROL S W
• Application Number:
  US11/874,562
• Time in Patent Office: 887 Days
• Field of Search: 702/182, 702/58, 356/338, 356/237.4, 356/491, 382/154, 382/145, 250/370.15, 250/338.4, 372/34, 372/36, 372/20, 324/767, 327/538
• US Class Current: 702/182
• CPC Class Codes: G01R 31/2635 Testing light-emitting diodes, laser diodes or photodiodes
• CPC Class Codes: H01S 5/0021 Degradation or life time measurements
• CPC Class Codes: H01S 5/4031 Edge-emitting structures

Abstract

Methods and systems for semiconductor diode junction protection.

Claims

1. A method for selecting a threshold sensitivity for detecting anomalous behavior of a semi conductor diode Junction, the threshold sensitivity being used in a semiconductor diode Junction device testing system, the method comprising the steps of:

a. selecting a threshold sensitivity value such that substantially no anomalous behavior is detected;

b. reducing the threshold sensitivity by a predetermined amount;

c. for one time interval from a plurality of time intervals, detecting, utilizing an optical power detector, optical power emitted from the semiconductor diode junction;

d. for said one time interval from said plurality of time intervals, determining, from detection of semiconductor diode Junction parameters and utilizing the threshold sensitivity, whether anomalous behavior of the semiconductor junction diode has occurred;

e. for said one time interval, determining, according to predetermined criteria, whether the determination of whether anomalous behavior has occurred is a true positive (TP), a false-negative (FN), a false-positive (FP) or a true negative (TN);

f. repeating steps c) through e) for each time interval in said plurality of time intervals;

g. determining, according to other predetermined criteria, a true positive fraction (TPF) and a false-positive fraction (FPF), a TPF, FPF pair corresponding to the threshold sensitivity;

h. repeating steps b) through g), obtaining the TPF, FPF pair corresponding to each threshold sensitivity; and

i. selecting from the TPF, FPF pairs, according to a selection criterion, a desired threshold sensitivity for detection of anomalous behavior;

whereby the threshold sensitivity is utilized in a threshold detector to detect anomalous behavior of the semiconductor diode Junction device.

2. The method of claim 1 wherein the threshold sensitivity is a predetermined semiconductor junction device voltage behavior;

and wherein the anomalous behavior is detected by comparing semiconductor junction device voltage to the threshold sensitivity.

3. The method of claim 1 wherein the threshold sensitivity is a predetermined semiconductor junction device current behavior;

and wherein the anomalous behavior is detected by comparing semiconductor junction device current to the threshold sensitivity.

4. The method of claim 1 wherein the threshold sensitivity is a predetermined semiconductor junction device emitted wavelength behavior;

and wherein the anomalous behavior is detected by comparing semiconductor junction device emitted wavelength to the threshold sensitivity.

5. The method of claim 1 wherein the threshold sensitivity is a predetermined semiconductor junction device emitted polarization behavior;

and wherein the anomalous behavior is detected by comparing semiconductor junction device emitted polarization to the threshold sensitivity.

6. The method of claim 1 wherein the total positive fraction is substantially equal to the ratio of a number of true positives to the sum of the number of true positives and a number of false negatives;

and wherein the false-positive fraction is substantially equal to the ratio of a number of false positives to the sum of the number of false positives and a number of true negatives.

7. The method of claim 1 wherein said predetermined criteria comprises:

identifying the determination that anomalous behavior of the semiconductor junction diode has occurred as a true positive (TP) when the detected optical power is less than an optical power detected at a preceding time interval;

identifying the determination that anomalous behavior of the semiconductor junction diode has not occurred as a false-negative (FN) when the detected optical power is less than an optical power detected at a preceding time interval;

identifying the determination that anomalous behavior of the semiconductor junction diode has occurred as a false-positive (FP) when the detected optical power is not less than an optical power detected at a preceding time interval; and

identifying the determination that anomalous behavior of the semiconductor junction diode has not occurred as a true-negative (TN) when the detected optical power is not less than an optical power detected at a preceding time interval.

8. The method of claim 1 wherein the selection criteria comprises substantially maximizing the true positive fraction and substantially minimizing the false-positive fraction.

11. The system of claim 8 wherein said threshold determining component comprises:

at least one processor; and

at least one computer usable medium having computer readable code embodied therein, said computer readable code being capable of causing said at least one processor to select a threshold value;

said threshold value being provided to said threshold detector.

12. The system of claim 11 wherein said computer readable code is also capable of causing said at least one processor to update an ROC curve.

13. The system of claim 12 wherein said computer readable code is also capable of causing said at least one processor to:

a. select a threshold value such that substantially no anomalous behavior is detected;

b. reduce the threshold value by a predetermined amount;

c. for one time interval from a plurality of time intervals, detect, utilizing an optical power detector, power emitted from the semiconductor diode junction;

d. for said one time interval from said plurality of time intervals, determine, from detection of semiconductor diode Junction parameters and utilizing the threshold detector, whether anomalous behavior of the semiconductor junction diode has occurred;

e. for said one time interval, determine, according to predetermined criteria, whether the determination of whether anomalous behavior has occurred is a true positive (TP), a false-negative (FN), a false-positive (FP) or a true negative (TN);

f. repeat steps c) through e) for each time interval in said plurality of time intervals;

g. determine, according to other predetermined criteria, a true positive fraction (TPF) and a false-positive fraction (FPF), a TPF, FPF pair corresponding to the threshold value; and

h. repeat steps b) through g), obtaining the TPF, FPF pair corresponding to each threshold value.

14. The system of claim 13 wherein the total positive fraction is substantially equal to the ratio of a number of true positives to the sum of the number of true positives and a number of false negatives;

and wherein the false-positive fraction is substantially equal to the ratio of a number of false positives to the sum of the number of false positives and a number of true negatives.

15. The system of claim 13 wherein said predetermined criteria comprises:

identifying the determination that anomalous behavior of the semiconductor junction diode has occurred as a true positive (TP) when the detected optical power is less than an optical power detected at a preceding time interval;

identifying the determination that anomalous behavior of the semiconductor junction diode has not occurred as a false-negative (FN) when the detected optical power is less than an optical power detected at a preceding time interval;

identifying the determination that anomalous behavior of the semiconductor junction diode has occurred as a false-positive (FP) when the detected optical power is not less than an optical power detected at a preceding time interval; and

identifying the determination that anomalous behavior of the semiconductor junction diode has not occurred as a true-negative (TN) when the detected optical power is not less than an optical power detected at a preceding time interval.

9. A method for selecting a threshold sensitivity for detecting anomalous behavior of a semiconductor diode Junction, the threshold sensitivity being used in a semiconductor diode Junction device testing system, the method comprising the step of:

a. determining a relationship between a rate of false positive detections of anomalous behavior and the threshold sensitivity; and

b. selecting a value of threshold sensitivity that provides substantially a maximum rate of false positive detections for a predetermined duty factor;

whereby the threshold sensitivity is utilized in a threshold detector to detect anomalous behavior of the semiconductor diode Junction device;

the anomalous behavior comprising non uniformities/instabilities in local current density and/or temperature of the semiconductor diode junction.

10. A system for selecting a threshold sensitivity for detecting anomalous behavior of a semi conductor diode Junction, the system comprising:

a component for detecting a value of a predetermined parameter of a semiconductor junction device;

a threshold detector capable of receiving said detected value of the predetermined parameter and a threshold value, said threshold device being capable of providing a signal indicative of whether anomalous device behavior has occurred;

a device protection component capable of reducing power from the semiconductor junction device when said signal indicates that anomalous device behavior has occurred;

an optical output detector capable of providing a detector signal indicative of optical output of the semiconductor junction device; and

a threshold determining component capable of receiving said detector signal and said signal and of providing the threshold value to said threshold detector.

16. The system of claim 10 wherein a threshold selection criterion comprises substantially maximizing the true positive fraction and substantially minimizing the false-positive fraction.

17. The system of claim 10 wherein the threshold value is a predetermined semiconductor junction device voltage behavior;

and wherein the component for detecting a value of a predetermined parameter determines semiconductor junction device voltage.

18. The system of claim 10 wherein the threshold value is a predetermined semiconductor junction device current behavior;

and wherein the component for detecting a value of a predetermined parameter determines semiconductor junction device current.

19. The system of claim 10 wherein the threshold value is a predetermined semiconductor junction device emitted wavelength behavior;

and wherein the component for detecting a value of a predetermined parameter determines semiconductor junction device emitted wavelength.

20. The system of claim 10 wherein the threshold value is a predetermined semiconductor junction device emitted polarization behavior;

and wherein the component for detecting a value of a predetermined parameter determines semiconductor junction device emitted polarization.