Method for manufacturing a solar cell from a substrate wafer

US5306647A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Volker Lehmann · Hersbruck, DE
• Reinhard Stengl · Stadtbergen, DE
• Hermann Wendt · Grasbrunn, DE
• Wolfgang Hoenlein · Unterhaching, DE
• Josef Willer · Riemerling, DE

Key dates

• Filing date: Dec 30, 1992
• Grant date: Apr 26, 1994
• Expiry date: Dec 30, 2012

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P70/50
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A self-supporting layer of n-doped monocrystalline silicon is stripped from a substrate wafer of n-doped, monocrystalline silicon by electrochemical etching for manufacturing a solar cell. Holes are formed in the substrate wafer by electrochemical etching, particularly in a fluoride-containing, acidic electrolyte wherein the substrate wafer is connected as an anode. When a depth of the holes that essentially corresponds to the thickness of the self-supporting layer is reached, the process parameters of the etching are modified such that the self-supporting layer is stripped as a consequence of the holes growing together. The solar cell is manufactured from the self-supporting layer, and the method can be applied repeatedly on the same substrate wafer for stripping a plurality of self-supporting layers.