Three-dimensional semiconductor template for making high efficiency solar cells

Patent metadata

Field	Value
Publication number	US-9590035-B2
Application number	US-201414195748-A
Country	US
Kind code	B2
Filing date	Mar 3, 2014
Priority date	Nov 13, 2008
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

A semiconductor template having a top surface aligned along a (100) crystallographic orientation plane and an inverted pyramidal cavity defined by a plurality of walls aligned along a (111) crystallographic orientation plane. A method for manufacturing a semiconductor template by selectively removing silicon material from a silicon template to form a top surface aligned along a (100) crystallographic plane of the silicon template and a plurality of walls defining an inverted pyramidal cavity each aligned along a (111) crystallographic plane of the silicon template.

First claim

What is claimed is:

1. A method for fabrication of a three-dimensional silicon template, the method comprising:
forming a patterned mask on a silicon template surface defining a pattern of base openings, said pattern of base openings comprising a pattern of at least two differently sized base openings;
selectively removing silicon material from said silicon template in said base openings to form a top surface aligned along a (100) crystallographic plane of the silicon template and a plurality of walls each aligned along a (111) crystallographic plane of the silicon template wherein said walls define inverted pyramidal cavities, said inverted pyramidal cavities comprising at least two differently sized inverted pyramidal cavities, said removal of silicon material comprising the steps of:
anisotropically etching the silicon template to form a plurality of walls each aligned along a (111) crystallographic plane of the silicon template wherein said walls form an inverted pyramidal cavity.

2. The method of claim 1 , wherein said step of anisotropically etching the silicon template utilizes KOH or NaOH as an etchant.

3. The method of claim 1 , wherein said step of anisotropically etching the silicon template utilizes TetraMethyl-Ammonium-Hydroxide (TMAH) as an etchant.

4. The method of claim 1 , wherein said patterned base openings of said patterned mask is a staggered pattern of at least two differently sized base openings.

5. The method of claim 1 , wherein said patterned mask is SiO 2 .

6. The method of claim 1 , wherein said patterned mask is SiN.

Assignees

• Solexel Inc

Inventors

• Wang David Xuan-Qi
• Moslehi Mehrdad M

Classifications

• H10P50/242

  of Group IV materials · CPC title

• H01L31/0236

  Electricity · mapped topic

• H01L31/1892

  Electricity · mapped topic

• Y10T117/1092

  Shape defined by a solid member other than seed or product [e.g., Bridgman-Stockbarger] · CPC title

• Y02E10/547

  Monocrystalline silicon PV cells · CPC title