Microwave separation measurements of bulk lifetime and surface recombination velocities in Si wafers with various surface properties

The separation measurements of a bulk lifetime {tau}{sub b}, front and back surface recombination velocities S{sub 0}, S{sub w} have been investigated for both 620 {micro}m and 1.08 mm thick Si wafers with various surface treatments. The separation was made by applying bisurface photoconductivity decay method to the photoconductivity decay curves measured by 500 MHz microwave reflection under the bias light illumination. The bulk lifetime and the surface recombination velocities have been determined, respectively, to be 624--659 {micro}s and 18.4--66.1 cm/s for the oxidized sliced-surface and 6,285 cm/s for the sliced surface. And they have been also determined, respectively, to be 412--422 {micro}s and <1 cm/s for the oxidized mirror polished-surface or the oxidized etched surface, 565--626 {micro}s and 1,042--1,112 cm/s for the oxidized sandblasted-surface. The noncontact microwave BSPCD method with bias lights makes it possible to determine separately the bulk lifetime and surface recombination velocities in the front surface and backsurface in Si wafers with the wafer thickness for the practical use.