Effect of different metal materials on the formation of Ohmic contacts to p-type SiC: A review

Abstract

As an emerging member of the semiconductor family, the third-generation semiconductor SiC has physical properties such as a wide bandgap, high critical field strength, and high thermal conductivity that render it a promising candidate for use in power devices. In the past decade, power devices supported by p-type SiC have gained considerable attention in the high temperature and high-power semiconductor industry owing to their enhanced device characteristics. However, the preparation of excellent Ohmic contacts between p-type SiC and a metal remains a challenge. In this context, most studies have focused on using various metal schemes on highly doped p-type SiC to reduce the specific contact resistance. Nevertheless, the obtained Ohmic contact stability is poor and cannot fully meet the application requirements. Research on metal schemes and contact mechanisms has been scarce. Here, metal schemes for forming Ohmic contacts on p-type SiC are comprehensively reviewed, with particular attention being paid to material mechanisms for obtaining Ohmic contacts. Furthermore, the carrier transport mechanism and band theory of metal/SiC contacts are also discussed. Additionally, the future development direction of the process of Ohmic contact formation on p-type SiC is discussed. © 2024