Iron Diffusion Profile Studies by Surface Photo-Voltage for Silicon Iron Implanted Wafers After Rapid Thermal Anneal

Abstract

Two-side Surface Photovoltage (TS-SPV) based on measuring SPV from both wafer sides is proposed as novel approach for silicon surface contamination monitoring. TS-SPV is applied to investigate the process of diffusion of implanted iron in lightly doped p-type silicon during Rapid Thermal Anneal (RTA). Good correlation was found for iron distribution vs. RTA conditions in the temperature range from 375 to 1100oC. The portion of electrically active interstitial iron measured by TS-SPV was studied as function of RTA time and temperature conditions. Low thermal budget RTA combined with TS-SPV is proven to be effective to monitor iron contamination and to identify the contamination sources character and location.