Integration of HfO2 on Si/SiC heterojunctions for the gate architecture of SiC power devices

摘要

In this paper we present a method for integrating HfO2 into the SiC gate architecture, through the use of a thin wafer bonded Si heterojunction layer. Capacitors consisting of HfO2 on Si, SiC, Si/SiC, and SiO2/SiC have been fabricated and electrically tested. The HfO2/Si/SiC capacitors minimize leakage, with a breakdown electric field of 3.5 MV/cm through the introduction of a narrow band gap semiconductor between the two wide band gap materials. The Si/SiC heterojunction was analyzed using transmission electron microscopy, energy dispersive x-ray, and Raman analysis, proving that the interface is free of contaminants and that the Si layer remains unstressed.