System and method for accelerated degradation testing of semiconductor devices

• US 5,381,103 A
• Filed: 10/13/1992
• Issued: 01/10/1995
• Est. Priority Date: 10/13/1992
• Status: Expired due to Term

• Current Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Original Assignee: Cree Research, Inc.
• Inventors: Asbury, Douglas A., Carter, Calvin H. Jr., Edmond, John A., Waltz, Douglas G.
• Primary Examiner(s): Wieder, Kenneth A.
• Assistant Examiner(s): BOWSER, BARRY
• Application Number:
  US07/959,714
• Time in Patent Office: 819 Days
• Field of Search: 324/158 D, 324/753, 29/537, 437/8
• US Class Current: 324/754.06
• CPC Class Codes: G01R 31/2635 Testing light-emitting diodes, laser diodes or photodiodes
• CPC Class Codes: G01R 31/2642 Testing semiconductor operation lifetime or reliability, e.g. by accelerated life tests

Abstract

A method of testing a semiconductor device, having the steps of pulsing the semiconductor device with a predetermined level of current for a duration of time so as to cause inadequate parts to degrade and to cause adequate parts to stabilize, and measuring predetermined electrical or optical performance characteristics for the semiconductor device after the current pulse. A system for testing a semiconductor device on a wafer is also provided having a contact probe for applying current pulses to the semiconductor device on the wafer, measuring means electrically connected to the probe for measuring predetermined electrical or optical performance characteristics of the semiconductor device on the wafer, and optical detection means electrically connected to the measuring means for detecting radiation emitted from the semiconductor device on the wafer.

Claims

1. A method of testing semiconductor device, comprising the steps of:

pulsing a semiconductor device being tested with a predetermined level of current higher than the average operational current level of the semiconductor device being tested for a duration of time of less than 15 seconds so as to cause an inadequate device being tested to degrade and to cause an adequate device being tested to stabilize; and

measuring predetermined electrical or optical performance characteristics for the semiconductor device after the current pulse.

2. A method of testing a semiconductor device according to claim 1, further comprising the step of initially measuring predetermined electrical or optical performance characteristics of a semiconductor device being tested prior to the step of pulsing the semiconductor device with a predetermined level of current.

3. A method of testing a semiconductor device according to claim 1, wherein the step of measuring predetermined electrical or optical performance characteristics of the semiconductor device is also performed during the step of pulsing the device with current.

4. A method of testing a semiconductor device according to claim 2, further comprising the step of terminating the testing of the semiconductor device if it fails to meet the predetermined electrical performance optical characteristics before the current pulse.

5. A method of testing a semiconductor device according to claim 2, wherein the step of initially measuring the predetermined electrical or optical performance characteristics of the semiconductor device includes measuring performance characteristics selected from the group consisting of:

forward voltage, reverse voltage, forward current, reverse current, hue, hue degradation, light output power, light output power degradation, luminous intensity, luminous intensity degradation, luminous efficacy, color, color degradation, peak color wavelength, dominant color wavelength, speed of response, capacitance, thermal resistance, power dissipation, and combinations thereof.

6. A method of testing a semiconductor device according to claim 1, wherein the predetermined current density of the current pulse ranges from 1666 A/cm² to 5000 A/cm².

7. A method of testing a semiconductor device according to claim 1, wherein the predetermined current density of the current pulse is about 3333 A/cm².

8. A method of testing a semiconductor device according to claim 1, wherein the semiconductor device is formed of silicon carbide.

9. A method of testing a semiconductor device according to claim 1, wherein the semiconductor device is a blue light emitting diode formed of silicon carbide.

10. A method of testing a semiconductor device according to claim 1, wherein the semiconductor device being tested comprises an optoelectronic device.

11. A method of testing a light emitting diode comprising the steps of:

pulsing a light emitting diode being tested with a predetermined level of current higher than the average operational current level of the light emitting diode being tested for a duration of time of less than 15 seconds so as to cause an inadequate light emitting diode to degrade and to cause an adequate light emitting diode to stabilize; and

measuring predetermined electrical or optical performance characteristics for the light emitting diode after the current pulse.

12. A method of testing a light emitting diode according to claim 11, further comprising the step of initially measuring predetermined electrical or optical performance characteristics of a light emitting diode prior to the step of pulsing the light emitting diode with a predetermined level of current.

13. A method of testing a light emitting diode according to claim 11, wherein the measuring predetermined electrical or optical performance characteristics step is also performed during the current pulse.

14. A method of testing a light emitting diode according to claim 12, wherein the initially measuring step is preceded by the step of mounting a wafer of light emitting diodes onto a probing machine for individually measuring the electrical or optical performance characteristics of each light emitting diode on the wafer.

15. A method of testing a light emitting diode according to claim 14, wherein the mounting step is followed by the step of contacting the light emitting diode with a measuring probe.

16. A method of testing a light emitting diode according to claim 12, wherein the initially measuring step is followed by the step of terminating the testing of the light emitting diode on the wafer if it fails to meet the predetermined electrical or optical performance characteristics, and prior to the step of pulsing the light emitting diode with a relatively high predetermined level of current.

17. A method of testing a light emitting diode according to claim 13, further comprising the step of marking the light emitting diode on the wafer with ink if it fails to meet the predetermined electrical optical performance characteristics measured during the current pulse.

18. A method of testing a light emitting diode according to claim 12, wherein the step of initially measuring the predetermined electrical or optical performance characteristics of the emitting diode being tested includes measuring performance characteristics selected from the group consisting of:

forward voltage, reverse voltage, forward current, reverse current, hue, hue degradation, light output power, light output power degradation, luminous intensity, luminous intensity degradation, luminous efficacy, color, color degradation, peak color wavelength, dominant color wavelength, speed of response, capacitance, thermal resistance, power dissipation, and combinations thereof.

19. A method of testing a light emitting diode according to claim 11, wherein the light emitting diode is formed of silicon carbide.

20. A method of testing a light emitting diode according to claim 11, wherein the light emitting is a blue light emitting diode formed of silicon carbide.

21. A method of testing a light emitting diode according to claim 11, wherein the predetermined current density of the current pulse ranges from 1666 A/cm² to 5000 A/cm².

22. A method of testing a light emitting diode according to claim 11, wherein the predetermined current density of the current pulse is about 3333 A/cm².

23. A method of testing a light emitting diode according to claim 11, further comprising the step of mapping the electrical or optical performance characteristics for the light emitting diodes under test.

24. A method of testing a wafer of light emitting diodes, comprising the steps of:

pulsing each light emitting diode on a wafer being tested with a predetermined level of current higher than the average operational current for the light emitting diode being tested for a duration of time of less than 15 seconds so as to cause inadequate light emitting diodes being tested to degrade and to cause adequate light emitting diodes being tested to stabilize; and

measuring predetermined electrical or optical performance characteristics for each light emitting diode after the current pulse.

25. A method of testing a wafer of light emitting diodes according to claim 24, further comprising the step of initially measuring predetermined electrical or optical performance characteristics of each individual light emitting diode on a wafer prior to the step of pulsing each light emitting with a predetermined level of current.

26. A method of testing a wafer of light emitting diodes according to claim 24, wherein the measuring predetermined electrical or optical performance characteristics step is also performed during the current pulse.

27. A method of testing a wafer of light emitting diodes according to claim 25, wherein the initially measuring step is preceded by the step of mounting a wafer of light emitting diodes onto a probing machine for individually measuring the electrical or optical performance characteristics of each light emitting diode on the wafer.

28. A method of testing a wafer of light emitting diodes according to claim 27, wherein the mounting step is followed by the step of contacting each individual light emitting diode with a measuring probe.

29. A method of testing a wafer of light emitting diodes according to claim 25, wherein the initially measuring step is followed by the step of terminating the testing of the light emitting diodes on the wafer failing to meet the predetermined electrical or optical performance characteristics, and prior to the step of pulsing each light emitting diode on the wafer with a predetermined level of current.

30. A method of testing a wafer of light emitting diode according to claim 29, further comprising the step of marking the light emitting diodes on the wafer with ink which fail meet the predetermined electrical or optical performance characteristics measured during the current pulse.

31. A method of testing a wafer of light emitting diodes according to claim 24, wherein the step of initially measuring predetermined electrical or optical performance characteristics of a wafer of light emitting diodes being tested includes measuring performance characteristics selected from the group consisting of:

forward voltage, reverse voltage, forward current, reverse current, hue, hue degradation, light output power, light output power degradation, luminous intensity, luminous intensity degradation, luminous efficacy, color, color degradation, peak color wavelength, dominant color wavelength, speed of response, capacitance, thermal resistance, and power dissipation, and combinations thereof.

32. A method of testing a wafer of light emitting diodes according to claim 24, wherein the predetermined current density of the current pulse ranges from 1666 A/cm² to 5000 A/cm².

33. A method of testing a wafer of light emitting diodes according to claim 24, wherein the predetermined current density of the current pulse is about 3333 A/cm².

34. A method of testing a wafer of light emitting diodes according to claim 24, wherein the wafer of light emitting diodes is formed of silicon carbide.

35. A method of testing a wafer of light emitting diodes according to claim 24, wherein the light emitting diodes of the wafer are blue light emitting diodes formed of silicon carbide.

36. A method of testing a wafer of light emitting diodes according to claim 24, further comprising the step of mapping the electrical or optical performance characteristics of the light emitting diodes for the wafer under test.

37. A system for testing a wafer of optoelectronic semiconductor devices prior to packaging, comprising:

a plurality of contact probes adapted for applying a pulse of a predetermined level of current higher than the average operational current level to a plurality of optoelectronic semiconductor devices on a wafer being tested for a period of time of less than 15 seconds to thereby degrade an inadequate device being tested and to stabilize an adequate device being tested;

measuring means electrically connected to said plurality of contact probes for measuring predetermined electrical or optical performance characteristics of the semiconductor device on the wafer being tested; and

optical detection means electrically connected to said measuring means for detecting radiation emitted from the optoelectronic semiconductor devices on the wafer being tested and thereby determined whether the optoelectronic semiconductor device has degraded after the current pulse.

38. A system for testing a semiconductor device on a wafer according to claim 37, wherein said measuring means comprises a photometer and a computing device.

39. A system for testing a semiconductor device on a wafer according to claim 37, wherein said optical detection means comprises a fiber optic probe.