Method for reducing and homogenizing the thickness of a semiconductor layer which lies on the surface of an electrically insulating material

US7988876B2 · kind B2 · utility

Assignee

• Siltronic AG · DE

Inventors

• Diego Feijoo · Burghausen, DE
• Oliver Riemenschneider · Kiel, DE
• Reinhold Wahlich · Burghausen, DE

Key dates

• Filing date: Jan 31, 2008
• Grant date: Aug 2, 2011
• Expiry date: Mar 31, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/30604
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

To reduce and homogenize the thickness of a semiconductor layer which lies on the surface of an electrically insulating material, the surface of the semiconductor layer is exposed to the action of an etchant whose redox potential is adjusted as a function of the material and the desired final thickness of the semiconductor layer, so that the material erosion per unit time on the surface of the semiconductor layer due to the etchant becomes less as the thickness of the semiconductor layer decreases, and is only from 0 to 10% of the thickness per second when the desired thickness is reached. The method is carried out without the action of light or the application of an external electrical voltage.