Controlling the stoichiometry and doping of semiconductor materials

Patent metadata

Field	Value
Publication number	US-9419170-B2
Application number	US-201514615068-A
Country	US
Kind code	B2
Filing date	Feb 5, 2015
Priority date	Feb 6, 2014
Publication date	Aug 16, 2016
Grant date	Aug 16, 2016

Abstract

Methods for treating a semiconductor material are provided. According to an aspect of the invention, the method includes annealing the semiconductor material in the presence of a compound that includes a first element and a second element. The first element provides an overpressure to achieve a desired stoichiometry of the semiconductor material, and the second element provides a dopant to the semiconductor material.

First claim

What is claimed is:

1. A method of treating a semiconductor material, the method comprising:
annealing the semiconductor material in the presence of a compound that includes a first element and a second element; wherein:
the first element provides a vapor overpressure to achieve a desired stoichiometry of the semiconductor material, wherein the stoichiometry is a ratio of components of the semiconductor material, and
the second element provides a dopant to the semiconductor material.

2. The method according to claim 1 , wherein a vapor pressure of the semiconductor material is lower than a vapor pressure of the compound.

3. The method according to claim 1 , wherein a vapor pressure of the first element is lower than a vapor pressure of the second element.

4. The method according to claim 1 , wherein the semiconductor material is CdTe or an alloy of CdTe, the first element is Cd, and the stoichiometry is Cd-rich.

5. The method according to claim 4 , wherein the second element is selected from Column VA of the periodic table.

6. The method according to claim 4 , wherein the second element is P, As, or Sb.

7. The method according to claim 4 , wherein the second element is P.

8. The method according to claim 4 , wherein the compound is Cd 3 P 2 .

9. The method according to claim 1 , wherein the semiconductor material is CdTe or an alloy of CdTe, the first element is Te, and the stoichiometry is Te-rich.

10. The method according to claim 9 , wherein the second element is selected from Column IB of the periodic table.

11. The method according to claim 9 , wherein the second element is Cu, Ag, or Au.

12. The method according to claim 1 , wherein the semiconductor material is CdTe or an alloy of CdTe, and the annealing is performed at a temperature greater than approximately 600° C.

13. The method according to claim 1 , wherein the semiconductor material is CdTe or an alloy of CdTe, and the annealing is performed at a temperature greater than approximately 700° C.

14. The method according to claim 1 , further comprising subsequently annealing the treated semiconductor material in the presence of the first element.

15. The method according to claim 14 , wherein the first element is Cd.

16. The method according to claim 14 , wherein the subsequent annealing is performed at a first temperature between approximately 300° C. and approximately 600° C.

17. The method according to claim 16 , further comprising heating the treated and subsequently annealed semiconductor material at a second temperature that is lower than the first temperature, and in the presence of ambient materials that promote at least one of annihilation or re-evaporation of excess quantities of the first element from the semiconductor material.

Assignees

• Alliance Sustainable Energy

Inventors

• Albin David
• Burst James
• Metzger Wyatt
• Duenow Joel
• Farrell Stuart
• Colegrove Eric

Classifications

• H10F77/1233

  characterised by the dopants · CPC title

• H10F71/125 Primary

  The active layers comprising only Group II-VI materials, e.g. CdS, ZnS or CdTe · CPC title

• Y02P70/521

  Cross-Sectional Technologies · mapped topic

• H01L31/1828 Primary

  Electricity · mapped topic

• H01L31/02963

  Electricity · mapped topic