Heat-resistant barrier and ohmic contacts based on TiBx and ZrBx interstitial phases to microwave diode structures

Abstract

We investigated thermal stability of Au–TiBx (ZrBx) barrier contacts, as well as ohmic contacts with a TiBx diffusion barrier to n-Si (GaAs, InP, GaP, GaN, SiC). The electrophysical measurements of Schottky barrier diodes and ohmic contacts were performed both before and after rapid thermal annealing (RTA) up to 600 °С for the structures on Si, GaAs, InP and GaP, as well as up to higher temperatures for GaN (~900 °C) and SiC (~1000 °C). The concentration depth profiles of contact components were taken using Auger electron spectrometry, while phase composition and surface morphology of the metallization layers on test structures were determined using x-ray diffraction and atomic force microscopy. It was shown that the silicon, indium phosphide, gallium phosphide and gallium arsenide contact structures retained their properties and layer structure after RTA up to 600 °С. Contact degradation occurred at a temperature of 800 °С. The structures based on SiC (GaN) remained stable at temperatures up to 1000 °С (900 °С).