Chemistry, microstructure, and electrical properties at interfaces between thin films of platinum and alpha (6H) silicon carbide (0001)

Abstract
Thin films (4-1000 Å) of Pt were deposited via UHV electron beam evaporation at room temperature on monocrystalline, n-type α (6H)-SiC(0001) substrates and examined in terms of chemistry, microstructure, and electrical properties. The as-deposited contacts were polycrystalline and showed excellent rectifying behavior with low ideality factors (n < 1.1) and leakage currents of 5 × 10−8 A/cm2 at −10 V. The Schottky barrier height increased from 1.06 eV before annealing to 1.26 eV after successive 20 min anneals at 450, 550, 650, and 750 °C. In addition, the leakage currents decreased to 2 × 10−8 A/cm2 at −10 V. Interfacial reactions were not observed at annealing temperatures below 750 °C; above this temperature, Pt2Si and C precipitates were identified in the reaction zone.