TiAl-based ohmic contacts on p-type SiC

Titanium-aluminum alloys were successfully used to form low resistance ohmic contacts to p-type SiC. This work concerns two Al-Ti alloy compositions. Contacts were prepared by magnetron sputtering of bilayer Al-Ti and trilayer Ti-Al-Ti thin films and rapid thermal annealing at temperatures range 900°C ÷ 1000°C. Using scanning electron microscopy and profiler, an investigation of surface morphology of annealed contacts was conducted. The best resistivity of 5.8·10
^-5
Ωcm
²
was attained on 100nm/26nm Al/Ti metallization of 80% at. Al alloy composition annealed at 1000°C for 2 min. Relatively low roughness of 30 nm was observed on trilayer Ti/Al/Ti metallization.