Influence of Contact Metallisation on the High Temperature Characteristics of High-κ Dielectrics

Abstract

In this work SiC-based MIS capacitors have been fabricated with different contact/high-k dielectric combinations and the temperature dependence of the characteristics have been examined in an N2ambient at temperatures between 323K and 673K. The structures utilise either a Pt or Pd catalytic gate contact and a TiO2or HfO2high-k dielectric, all of which are grown on a thin SiO2layer, thermally grown on the Si face of a 4H SiC epitaxial layer. The MIS capacitors have been studied in an N2 ambient between 323K and 673K and observations show that VFBreduces with increasing temperature. The majority of this variation is caused a reduction in the Ditinfluencing the structures electrical characteristics, due to a shift in the semiconductors bulk potential, which is due to the lower VTHof SiC-based MOSFETs at high temperatures.