Method for forming a compound semi-conductor thin-film

• US 8,431,430 B2
• Filed: 05/23/2012
• Issued: 04/30/2013
• Est. Priority Date: 04/02/2008
• Status: Active Grant

• Current Assignee: Sunlight Aerospace Incorporated
• Original Assignee: Sunlight Photonics Incorporated
• Inventors: Bruce, Allan James, Frolov, Sergey, Cyrus, Michael
• Primary Examiner(s): Vu, David
• Assistant Examiner(s): TAYLOR, EARL N
• Application Number:
  US13/478,851
• Publication Number:
  US 20120228731A1
• Time in Patent Office: 342 Days
• Field of Search: 438/77, 438 93- 95, 438/483, 438602-608, 438/767, 438/84
• US Class Current: 438/93
• CPC Class Codes: H01L 21/02551 Group 12/16 materials
• CPC Class Codes: H01L 21/02568 Chalcogenide semiconducting materials not being oxides, e.g. ternary compounds
• CPC Class Codes: H01L 21/02573 Conductivity type
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 31/0322 comprising only AIBIIICVI chalcopyrite compounds, e.g. Cu In Se2, Cu Ga Se2, Cu In Ga Se2
• CPC Class Codes: H01L 31/0392 including thin films deposited on metallic or insulating substrates ; characterised by specific substrate materials or substrate features or by the presence of intermediate layers, e.g. barrier layers, on the substrate textured substrates H01L31/02366
• CPC Class Codes: H01L 31/03923 including AIBIIICVI compound materials, e.g. CIS, CIGS
• CPC Class Codes: H01L 31/03925 including AIIBVI compound materials, e.g. CdTe, CdS
• CPC Class Codes: H01L 31/1828 the active layers comprising only AIIBVI compounds, e.g. CdS, ZnS, CdTe
• CPC Class Codes: H01L 31/1832 comprising ternary compounds, e.g. Hg Cd Te
• CPC Class Codes: Y02E 10/541 CuInSe2 material PV cells
• CPC Class Codes: Y02E 10/543 Solar cells from Group II-VI materials
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method is provided for fabricating a thin film semiconductor device. The method includes providing a plurality of raw semiconductor materials. The raw semiconductor materials undergo a pre-reacting process to form a homogeneous compound semiconductor target material. The compound semiconductor target material is deposited onto a substrate to form a thin film having a composition substantially the same as a composition of the compound semiconductor target material.

Claims

1. A method of fabricating a light-absorbing thin-film, comprising:

providing a plurality of raw semiconductor materials;

pre-reacting the raw semiconductor materials to form a homogeneous compound semiconductor target material; and

depositing the compound semiconductor target material onto a substrate to form a light-absorbing thin-film having a composition substantially the same as a composition of the compound semiconductor target material.

2. The method of claim 1 wherein the raw semiconductor materials include II-VI compound semiconductor materials.

3. The method of claim 1, wherein the raw semiconductor materials include I-III-VI compound semiconductor materials.

4. The method of claim 2 wherein the IIB-VIA compound semiconductor materials are selected from the group consisting of Cd—

S, Cd—

Se, Cd—

Te, Cd—

Zn—

Te, Cd—

Hg—

Te.

5. The method of claim 3 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se.

6. The method of claim 3 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se, with Al and, or Ga as partial or complete compositional substitutes for In.

7. The method of claim 3 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se, with Ag partial replacing Cu.

8. The method of claim 3 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se, with S or Te as partial or complete replacements for Se.

9. A light-absorbing thin-film fabricated in accordance with the method set forth in claim 1.

10. The method of claim 1 wherein the raw semiconductor materials are pre-reacted above a liquidus temperature of the compound semiconductor target material.

11. The method of claim 3 wherein the I-III-VI compound semiconductor materials are selected from the group consisting of Cu—

In—

Se, Cu—

In—

Ga—

Se, Cu—

In—

Ga—

Se—

S.

12. The method of claim 11 further comprising providing Al in complete or partial substitution for Ga.

13. The method of claim 11 further comprising providing Na as a minor constituent along with the I-III-VI compound semiconductor materials.

14. The method of claim 11 further comprising providing an alkali element other than Na as a minor constituent long with the I-III-VI compound semiconductor materials.

15. The method of claim 14 further comprising providing F as a minor constituent along with the I-III-VI compound semiconductor materials.

16. The method of claim 14 further comprising providing a halogen element other than F as a minor constituent along with the I-III-VI compound semiconductor materials.

17. The method of claim 1 wherein the compound semiconductor target material is deposited by physical vapor deposition.

18. The method of claim 17 wherein the compound semiconductor target material is deposited by magnetron sputtering.

19. The method of claim 17 wherein the compound semiconductor target material is deposited by laser ablation.

20. The method of claim 1 wherein pre-reacting the raw semiconductor materials includes isolating the raw semiconductor materials at an elevated temperature to establish a structure and bonding profile representative of the deposited thin-film.

21. A method of fabricating a photovoltaic device, comprising:

forming a first electrode on a substrate;

forming a light absorbing layer on the first electrode, wherein forming the light absorbing layer includes;

providing a plurality of raw semiconductor materials;

pre-reacting the raw semiconductor materials to form a homogeneous compound semiconductor target material; and

depositing the compound semiconductor target material onto a substrate to form a thin-film having a composition substantially the same as a composition of the compound semiconductor target material; and

forming a second electrode over the light absorbing layer.

22. A photovoltaic device fabricated in accordance with the method set forth in claim 21.

23. The photovoltaic device of claim 22 wherein the raw semiconductor materials include II-VI compound semiconductor materials.

24. The photovoltaic device of claim 22, wherein the raw semiconductor materials include I-III-VI compound semiconductor materials.

25. The photovoltaic device of claim 23 wherein the IIB-VIA compound semiconductor materials are selected from the group consisting of Cd—

S, Cd—

Se, Cd—

Te, Cd—

Zn—

Te, Cd—

Hg—

Te.

26. The photovoltaic device of claim 24 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se.

27. The photovoltaic device of claim 24 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se, with Al and, or Ga as partial or complete compositional substitutes for In.

28. The photovoltaic device of claim 24 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se, with Ag partial replacing Cu.

29. The photovoltaic device of claim 24 wherein the IB-IIIA-VIA compound semiconductor materials are selected from the group consisting of Cu—

In—

Se, with S or Te as partial or complete replacements for Se.

30. The photovoltaic device of claim 22 wherein the raw semiconductor materials are pre-reacted above a liquidus temperature of the compound semiconductor target material.