Low Temperature Ni-Al Ohmic Contacts to p-Type 4H-SiC Using Semi-Salicide Processing

Most semiconductor devices require low-resistance ohmic contact to p-type doped regions. In this work, we present a semi-salicide process that forms low-resistance contacts (~10 -4 Ω cm 2 ) to epitaxially grown p-type (>5×10 18 cm -3 ) 4H-SiC at temperatures as low as 600 °C using rapid thermal processing (RTP). The first step is to self-align the nickel silicide (Ni 2 Si) at 600 °C. The second step is to deposit aluminium on top of the silicide, pattern it and then perform a second annealing step in the range 500 °C to 700 °C.