Ion-irradiation-induced porosity in GaSb and InSb

Abstract

Ion irradiation of crystalline GaSb and InSb can yield not only amorphisation, as commonly observed in semiconductors, but also porosity. Extended x-ray absorption fine structure spectroscopy, electron microscopy and Rutherford backscattering spectrometry have been used to determine the exact nature of and relationship between these two transformations. In both materials, low dose, room temperature implantation produces spherical voids yet the material remains crystalline. With increasing implant dose, the porous layer eventually evolves into a network of straight rods 15nm in diameter. We suggest the porosity arises from preferential clustering of interstitials into extended defects and vacancies agglomerating to form voids.