Comparison of Silicon Surface Preparation Methods for Measurement of Minority Carrier Lifetime using the Microwave Photo-conductive Decay (μ-PCD) coupled with Continuous Corona Charge (Charge-PCD)

Abstract

Experimental results for a new method of measuring the minority carrier lifetime as a process control tool to determine trace metal contamination following wafering and/or epitaxial growth of silicon in a production environment are reported. In this new method the minority carrier lifetime by is measured by microwave photo-conductive decay (μ-PCD) while charging the surface silicon oxide with a corona charge. We have named the method Charge-PCD. Results are given comparing various qualities of the surface oxides prepared by low temperature methods coupled with various corona charging recipes in order to determine the optimum process and limitations of the new method.