Metal Contact on P-Type 4H-SiC With Low Specific Contact Resistance and Micrometer-Scale Contact Area

In this study, metal contact on p-type SiC with low specific contact resistance was developed using TiAl. Using fine-tuned TiAl deposition and annealing conditions on p-type SiC, the Ti-Si-C interfacial layer grown on high temperature ion implanted P+ SiC is nonuniform and exhibits nonohmic behavior when the contact area becomes smaller than 10 mu m x 10 mu m. This area dependence can be improved through low-energy, room-temperature (LERT) ion implantation and Ar plasma treatment prior to metal deposition. Ar plasma treatment results in a uniform Al-Si-C interfacial layer. Moreover, the defects produced by LERT ion implantation promote trap-assisted tunneling. Through the aforementioned methods, metal contact on p-type SiC with a record-low specific contact resistance of 3 x 10(-5) Omega cm(2) at record-small contact area of 1.5 mu m x 1.5 mu m was obtained in this study.