High-resistivity regions in n-type InGaAsP produced by 4He+ ion bombardment at 80 and 300 K

Abstract

The formation of high-resistivity regions in Si-doped (n=1×1018 cm−3) lattice-matched In0.75Ga0.25As0.54P0.46 on InP by helium ion bombardment at 300 and 80 K has been investigated as a function of ion dose (1×1012–1×1016 cm−2) and subsequent annealing temperature (70–650 °C) by sheet resistance and Hall effect measurements as a function of temperature. Irradiations at 300 K are found to induce an increase in the resistivity by a factor of up to 3×105 relative to that of the unimplanted material. Materials bombarded at 80 K with doses higher than 7×1014 cm−2 exhibit a further increase in the sheet resistance and higher stability upon subsequent annealing. Rutherford backscattering channeling results suggest that this behavior is related to the creation of a highly polycrystalline or amorphous region in the InGaAsP layer which occurs for irradiations performed at 80 K, but not at 300 K.