Mapping of trap densities and energy levels in semiconductors using a lock-in infrared camera technique

摘要

We examine nonrecombination active minority-carrier trapping centers in crystalline silicon using a lock-in infrared camera technique. Application of a simple trapping model to the injection-dependent lifetime data obtained from the infrared emission signal results in high-resolution mappings (spatial resolution =170 μm) of the trap density and the energy level. Measurements on Czochralski-grown silicon wafers show striation-related inhomogeneities of the trap density and a very homogeneous distribution of energy levels.