A deep-level analysis of Ni–Au/AlN/(1 1 1) p+-Si metal–insulator–semiconductor capacitors

Abstract

Deep levels formed by the growth of a 200 nm AlN buffer layer on highly B-doped (1 1 1) Czochralski Si substrates are investigated by deep-level transient spectroscopy on metal–insulator–semiconductor capacitors. The spectra reveal both a high density of interface states and a high concentration of extended defects in the silicon substrate. Annealing of the AlN buffer for 2840 s in NH3/H2 at 1130 °C, corresponding to the thermal budget for further growth of the AlGaN/GaN layers for high-voltage power devices, results in a reduction of the density of interface states and a transformation of the near-interface bulk defects. At the same time, it is found that annealing reduces the tensile strain and the bow of the AlN/Si substrates.