Electrical Performance of GaN Schottky Rectifiers on Si Substrates

Schottky rectifiers fabricated on GaN layers grown on 4 in. diam Si substrates show breakdown voltages (V(R)) of ~300 V at room temperature, on-state resistances (R(ON)) of 40 mOmega cm2, and figure-of-merit (V(B))2/S(ON) of 2.25 MW/cm2. The reverse current is thermally activated with activation energies in the range 0.3-0.4 eV and is proportional to contact perimeter at reverse biases up to ~100 V. This approach provides a low-cost alternative to GaN rectifiers on sapphire or SiC substrates while still maintaining good breakdown characteristics.