Patent ID: 7629054
Filing Date: 2009-12-08
Classification: C30B,H01L,Y10T

Abstract:
1. A single crystal silicon wafer for use in the production of insulated gate bipolar transistors (IGBT) which is made of single crystal silicon grown by the Czochralski method and has a gate oxide with a film thickness of from 50 to 150 nm, wherein the wafer has an interstitial oxygen concentration of at most 7.0×10 17 atoms/cm 3 , a resistivity variation within the plane of the wafer of at most 5% and, letting t ox (cm) be the gate oxide film thickness and S (cm 2 ) be the electrode surface area when determining the TZDB pass ratio, a density d (cm −3 ) of crystal originated particles (COP) having a size at least twice the gate oxide film thickness which satisfies the following formula (1):