Interface recombination velocity measurements for SOI wafers by μ-PCD with electric field

摘要

The microwave reflectance photoconductivity decay (μ-PCD) method is high speed, highly sensitive and non-contact lifetime measurement. In this study, to characterize interface of Silicon On Insulator (SOI), we attempted interface-recombination-velocity measurement for SOI wafers by μ-PCD. We measured lifetime, suppressing interface recombination by applying voltage between SOI and the substrate. Then interface -recombination velocity was estimated by comparing two lifetime values with and without voltage application. We characterized various bonded SOI wafers. We found that the value is greatly different between samples and even depending on position in the same sample. The value is from 100 to 2000 cm/s, relatively large as that for thermally oxidized Si/SiO{sub}2 interfaces.