Method for improved patterning accuracy for thin film photovoltaic panels

• US 8,263,494 B2
• Filed: 01/14/2011
• Issued: 09/11/2012
• Est. Priority Date: 01/25/2010
• Status: Expired due to Fees

• Current Assignee: Stion Corporation
• Original Assignee: Stion Corporation
• Inventors: Patterson, Frank
• Primary Examiner(s): Coleman, William D
• Assistant Examiner(s): ENAD, CHRISTINE A
• Application Number:
  US13/006,710
• Publication Number:
  US 20110256661A1
• Time in Patent Office: 606 Days
• Field of Search: 438/95, 438/102, 438/799, 438/699, 427/75, 257/E31.003
• US Class Current: 438/669
• 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 31/0463 characterised by special patterning methods to connect the PV cells in a module, e.g. laser cutting of the conductive or active layers
• CPC Class Codes: Y02E 10/541 CuInSe2 material PV cells

Abstract

A method for patterning a thin film photovoltaic panel on a substrate characterized by a compaction parameter. The method includes forming molybdenum material overlying the substrate and forming a first plurality of patterns in the molybdenum material to configure a first patterned structure having a first inter-pattern spacing. Additionally, the method includes forming a precursor material comprising at least copper bearing species and indium bearing species overlying the first patterned structure. Then the substrate including the precursor material is subjected to a thermal processes to form at least an absorber structure.

Claims

1. A method for patterning a thin film photovoltaic panel, the method comprising:

providing a substrate having a first edge opposing to a second edge, the substrate characterized by a compaction parameter;

forming a molybdenum material overlying the substrate;

forming a first plurality of patterns in the molybdenum material configured in a spatial configuration having a first inter-pattern spacing from the first edge to the second edge to form a first patterned structure overlying the substrate, wherein the first inter-pattern spacing is equal to a predetermined standard cell dimension plus an additional distance determined as a function of the compaction parameter;

forming a precursor material comprising at least copper bearing species and indium bearing species overlying the first patterned structure;

subjecting the substrate including the first patterned structure overlaid by the precursor material to one or more thermal processes to form at least an absorber structure and cause the substrate to change in dimension associated with the compaction parameter and subsequently to change the first inter-pattern spacing to a second inter-pattern spacing;

forming a window material overlying the absorber structure; and

scribing at least through one or more portions of the window material and the absorber structure at a position on the substrate shifted by a predetermined distance from one of the first plurality of patterns to cause formation of a second plurality of patterns characterized by a third inter-pattern spacing.

2. The method of claim 1 wherein the substrate comprises a glass material configured in substantially a rectangular shape.

3. The method of claim 1 wherein the compaction parameter is a constant independent of a position on the substrate.

4. The method of claim 1 wherein the compaction parameter is a function of a distance from the first edge of the substrate.

5. The method of claim 1 wherein the forming a first plurality of line patterns in the molybdenum material comprises scanning a laser beam to remove a first portion of the molybdenum material, shifting the laser beam position by the first inter-pattern spacing away, and scanning the laser beam to remove a second portion of the molybdenum material.

6. The method of claim 1 wherein the first inter-pattern spacing is determined to compensate a change in dimension of the substrate to be caused by the one or more thermal processes based on the compaction parameter.

7. The method of claim 1 wherein the window material comprises a cadmium sulfide material.

8. The method of claim 1 wherein the scribing at least through one or more portions of the window material and the absorber structure comprises using a scribe device including two or more mechanical tips having a tip-tip separation equal to the third inter-pattern spacing.

9. The method of claim 1 wherein the third inter-pattern spacing is substantially equal to the second inter-pattern spacing.

10. The method of claim 1 wherein the scribing at least through one or more portions of the window material and the absorber structure further comprises forming a recessed region of no greater than 200 Angstroms into the molybdenum material for each of the second plurality of line patterns.

11. The method of claim 1 wherein the one or more thermal processes to form an absorber structure comprises treating the precursor material in a gaseous environment comprising selenium species or sulfur species in one or more predetermined temperature cycles.

12. The method of claim 11 wherein the compaction parameter is derived by subjecting a sample substrate to the one or more predetermined temperature cycles, the sample substrate and the substrate in claim 1 being selected from a same lot of as-formed glass substrates.

13. The method of claim 1 wherein each of the second plurality of patterns is substantially shifted by a same predetermined distance from a corresponding one of the first plurality of patterns.

14. The method of claim 1 further comprising forming a transparent conductive oxide material overlying the second patterned structure.

15. The method of claim 14 further comprising scribing through one or more portions of the transparent conductive material to cause formation of a third plurality of patterns characterized by the third inter-pattern spacing, each of the third plurality of line patterns being shifted by a predetermined second distance from each of the second plurality of patterns.

16. The method of claim 1, wherein the function of compaction parameter equals the product of the compaction parameter and the predetermined standard cell dimension.

17. The method of claim 1, wherein the compaction parameter is between 500 ppm and 600 ppm.

18. A method for pre-compensating patterns on thin film panels, the method comprising:

providing a glass substrate characterized by a compaction ratio, the compaction ratio being dependent on one or more thermal cycles;

forming a first film overlying the glass substrate;

forming a first patterned structure in the first film the first patterned structure characterized by a first plurality of patterns having a first inter-pattern spacing pre-compensated by the compaction ratio;

forming at least a second film overlying the first patterned structure;

processing the second film through the one or more thermal cycles, the one or more thermal cycles transforming the first inter-pattern spacing to a second inter-pattern spacing while the substrate is being subjected to a compaction based on the compaction ratio;

scribing at least two or more portions of the second film using a scribe device to form a second plurality of patterns, the scribe device including two or more mechanical tips having a pre-determined tip-to-tip separation substantially equal to the second inter-pattern spacing, each of the second plurality of patterns being respectively shifted a distance from one of the first plurality of patterns.