METHOD AND SYSTEM EMPLOYING A SOLUTION CONTACT FOR MEASUREMENT

• US 20130314093A1
• Filed: 05/22/2013
• Published: 11/28/2013
• Est. Priority Date: 05/22/2012
• Status: Abandoned Application

• Current Assignee: First Solar Incorporated
• Original Assignee: First Solar Incorporated
• Inventors: Cheng, Long, Gloeckler, Markus
• Application Number:
  US13/900,177
• Publication Number:
  US 20130314093A1
• Time in Patent Office: Days
• US Class Current: 324/425
• CPC Class Codes: G01N 17/02 Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
• CPC Class Codes: G01N 27/416 Systems G01N27/27 takes precedence

Abstract

An inline metrology method and system using an electrolytic cell for measuring electrical characteristics of a semiconductor device, such as a photovoltaic device, during manufacture.

Claims

1. A metrology system for analyzing a semiconductor device comprising:

an electrolytic cell comprising;

a source of an electrolyte solution configured to provide the electrolyte solution in contact with at least a portion of a semiconductor material of the semiconductor device; and

a first electrode in contact with a provided electrolyte solution to enable measurement of electrical characteristics of the semiconductor device, wherein the portion of the semiconductor material of the semiconductor device acts as a second electrode when contacted by the electrolyte solution; and

a measurement circuit for taking electrical measurements using the electrolyte solution and the first electrode.

2. The metrology system of claim 1, wherein the first electrode is configured to apply at least one of a current and a voltage to the electrolyte solution.

3. The metrology system of claim 1, further comprising a third electrode located within a provided solution configured to establish a known reference potential in the electrolyte solution.

4. The metrology system of claim 2, wherein the measuring circuit comprises a source of at least one of voltage and current coupled to the first electrode.

5. The metrology system of claim 1, wherein the measurement circuit further comprises a device contact configured to contact a portion of a transparent conductive oxide layer of the semiconductor device.

6. The metrology system of claim 1, wherein the measuring circuit comprises a processing module.

7. The metrology system of claim 1, wherein at least one of the voltage characteristics and the current characteristics of the semiconductor device are measured during the analysis.

8. The metrology system of claim 1, wherein the electrolytic cell further comprises a chamber for supplying and withdrawing the electrolyte solution.

9. The metrology system of claim 8, wherein the chamber does not contact the semiconductor material of the semiconductor device.

10. The metrology system of claim 8, wherein the chamber is configured such that the solution is provided in contact with an entirety of a surface of the semiconductor material of the semiconductor device.

11. The metrology system of claim 1, wherein the source of electrolyte solution comprises a solution control module for controllably releasing the electrolyte solution.

12. The metrology system of claim 11, wherein the solution control module is configured to withdraw the electrolyte solution from the semiconductor material of the semiconductor device.

13. The metrology system of claim 1, further comprising at least one light source for illuminating the semiconductor device during electrical measurement.

14. The metrology system of claim 13, wherein intensity of the light source is adjustable.

15. The metrology system of claim 1, wherein the electrolyte solution comprises at least one salt.

16. The metrology system of claim 1, wherein the electrolyte solution comprises at least one material selected from the group consisting of chlorides, sulfates, phosphates, nitrates, and carbonates.

17. The metrology system of claim 15, wherein the electrolyte solution comprises a salt in an aqueous media.

18. The metrology system of claim 15, wherein the electrolyte solution comprises a salt in an organic media.

19. The metrology system of claim 1, wherein the first electrode comprises at least one of ferricyanide, ferrocyanide, ferrocene, benzoquinone, Tris(bipyridine)ruthenium(II) chloride, tetracyanoquinodimethane, tetrathiafulvalene, porphyrins, or phthalocyanines.

20. The metrology system of claim 1, wherein the semiconductor device is a photovoltaic device and the semiconductor material is a semiconductor layer of the photovoltaic device.

21. A method of analyzing a semiconductor device during a semiconductor device manufacturing process comprising:

applying an electrolyte solution to at least a portion of a semiconductor material of the semiconductor device;

applying a first electrode to the electrolyte solution, wherein the first electrode is configured to enable measurement of electrical characteristics of the semiconductor device and wherein the portion of the semiconductor material of the semiconductor device acts as a second electrode when being analyzed;

applying at least one of a voltage and current to the electrolyte solution; and

analyzing at least one electrical characteristic of the semiconductor device based on the one of a voltage and current applied to the electrolyte solution.

22. The method of claim 21, further comprising applying a third electrode to the electrolyte solution, wherein the one of a voltage and current is applied to the electrolyte solution at the third electrode.

23. The method of claim 21, further comprising applying at least one of a current and a voltage to the electrolyte solution at the first electrode.

24. The method of claim 21, further comprising applying at least one of a current and a voltage to the electrolyte solution at the portion of the semiconductor material of the semiconductor device.

25. The method of claim 23, further comprising:

sweeping a current output of the first electrode from approximately 0 mA/cm² to an upper current limit; and

measuring voltage characteristics of the semiconductor device.

26. The method of claim 23, further comprising:

sweeping a current output of the first electrode from a negative lower current limit, which is equal to or larger than the short-circuit current of the semiconductor device to an upper current limit; and

measuring voltage characteristics of the semiconductor device.

27. The method of claim 23, further comprising:

sweeping a voltage output of the first electrode from a lower voltage limit to an upper voltage limit; and

measuring current characteristics of the semiconductor device.

28. The method of claim 21, wherein applying the electrolyte solution comprises releasing the electrolyte solution from a solution control module against the semiconductor material of the semiconductor device.

29. The method of claim 21, further comprising placing a chamber containing the electrolyte solution adjacent to the semiconductor material of the semiconductor device.

30. The method of claim 29, wherein the chamber does not contact the semiconductor device.

31. The method of claim 21, further comprising inserting the semiconductor device into a bath comprising the electrolyte solution.

32. The method of claim 28, further comprising withdrawing the electrolyte solution from the semiconductor material of the semiconductor device.

33. The method of claim 21, further comprising illuminating the semiconductor device during the analysis with a light source.

34. The method of claim 33, further comprising varying an intensity of the light source during the analysis.

35. The method of claim 21, further comprising rinsing the semiconductor material of the semiconductor device.

36. The method of claim 21, further comprising:

comparing the electrical characteristic to a parameter to determine irregularities in the electrical characteristic;

communicating the comparison to the manufacturing process; and

adjusting the semiconductor device manufacturing process to compensate if irregularities are determined.

37. The method of claim 21, further comprising:

applying the electrolyte solution to at least a second portion of the semiconductor material of the semiconductor device;

applying the first electrode to the electrolyte solution, wherein the first electrode is configured to establish a reference potential in the electrolyte solution; and

analyzing at least one electrical characteristic of the semiconductor device at the second portion of the semiconductor material based on the reference potential generated in the electrolyte solution.