THE SCANNING INFRARED MICROSCOPE (SIRM) AND ITS APPLICATION TO BULK GAAS AND SI - A REVIEW

The development of the scanning infrared microscope (SIRM) at Oxford during the last few years and its application to the examination of inhomogeneities in a variety of bulk semiconductor specimens are described. Our present SIRM uses a 1.3-mu-m wavelength semiconductor laser and operates in bright field in either the standard, confocal or polarized light modes and in dark-field in the standard mode. It can reveal individual precipitate particles and dislocations and also point defect concentrations and local strain fields. It has a spatial resolution of 1-2-mu-m, a depth of field of 7-50-mu-m and can image particles down to 30 nm in size. Three-dimensional distributions of inhomogeneities can be determined. The method is non-destructive and non-contacting. Examples of its application to bulk in-doped GaAs, undoped GaAs and Si, both as-grown and post-annealed, are given. Quantitative data obtained include precipitate particle number density, particle denuded zone depth, dislocation geometry, dislocation particle decoration and dislocation Burgers vector.