Patent ID: 7837791
Filing Date: 2010-11-23
Classification: C30B

Abstract:
1. A method of making a silicon single crystal wafer for a particle monitor comprising the steps of, growing an ingot by the Czochralski method, wherein a time period of passing the ingot through a temperature range from 1150° C. to 1070° C. is controlled to be within 20 minutes and a time period of passing the ingot through a temperature range from 900° C. to 800° C. is controlled to be within 40 minutes, wherein said silicon single crystal ingot has a nitrogen concentration of 1×10 wherein said wafer is prepared by slicing a silicon single crystal ingot into wafers, the sliced wafer comprising a wafer body having a density of COP's and BMD's along an entire thickness of the wafer body, and wherein a density of particles per unit area having a particle size of not less than 0.12 μm across the entire thickness of the wafer is not more than 1 counts/cm