Methods for making wafers with low-defect surfaces, wafers obtained thereby and electronic components made from the wafers

US7367865B2 · kind B2 · utility

Assignee

• Schott AG · DE

Inventors

• Peter Blaum · Weiterstadt, DE
• Burkhard Speit · Mainz, DE
• Ingo Koehler · Darmstadt, DE
• Bernd Ruediger · Wörrstadt, DE
• Wolfram Beier · Essenheim, DE

Key dates

• Filing date: Mar 1, 2005
• Grant date: May 6, 2008
• Expiry date: Mar 1, 2025

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B24B37/042
• WIPO field: Machine tools
• WIPO sector: Mechanical engineering

Abstract

The electronic semiconductor component has a crystalline wafer substrate with an active surface and a semiconductor layer coating the active surface. So that the semiconductor layer has a few surface defects the crystalline wafer substrate is a sapphire or silicon carbide single crystal and the active surface has a pit density of less than 500 pit/cm2, preferably less than 100 pit/cm2. The polishing method for obtaining the active surface with these pit densities includes polishing with a polishing agent, such as a silicon suspension, and a polishing tool, which is pressed on the active surface with a pressure of preferably from 0.05 to 0.2 kg/cm2 and moved over the active surface with polishing motions distributed statistically and uniformly over a 360° angle during polishing.