Patent ID: 7084048

Claim:
A process for removing a contaminant selected from among copper, nickel, and a combination thereof from a silicon wafer having a silicon wafer surface and a silicon wafer interior, the process comprising: a) cooling the silicon wafer in a controlled atmosphere from a temperature above an oxidation initiation temperature; b) initiating a flow of an oxygen-containing atmosphere at said oxidation initiation temperature to create an oxidizing ambient around the silicon wafer surface to form an oxide layer on the silicon wafer surface and a strain layer at an interface between the oxide layer and the silicon wafer interior; c) controlling the cooling of the silicon wafer from said oxidation initiation temperature to permit diffusion of atoms of the contaminant from the silicon wafer interior to the strain layer; and d) cleaning the silicon wafer to remove the oxide layer and the strain layer, thereby removing said contaminant having diffused to the strain layer.