Self-aligned process and method for fabrication of high efficiency solar cells

US8153496B1 · kind B1 · utility

Assignee

• Varian Semiconductor Equipment Associates, Inc. · US

Inventor

• Deepak A. Ramappa · Dallas, US

Key dates

• Filing date: Mar 7, 2011
• Grant date: Apr 10, 2012
• Expiry date: Mar 7, 2031

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50

Abstract

An improved method of doping a substrate is disclosed. The method is particularly beneficial to the creation of interdigitated back contact (IBC) solar cells. A patterned implant is performed to introduce a first dopant to a portion of the solar cell. After this implant is done, an oxidation layer is grown on the surface. The oxide layer grows more quickly over the implanted region than over the non-implanted region. An etching process is then performed to remove a thickness of oxide, which is equal to the thickness over the non-implanted regions. A second blanket implant is then performed. Due to the presence of oxide on portions of the solar cell, this blanket implant only implants ions in those regions which were not implanted previously.