CHEMICAL-VAPOR-DEPOSITION OF TUNGSTEN SCHOTTKY DIODES TO 6H-SIC

Thermally stable tungsten Schottky contacts to low doped GH-silicon ca rbide (SiC) were fabricated via chemical vapor deposition at 670 K fol lowed by a reactive ion etch to pattern the contacts. Physical charact erization by x-ray diffraction, x-ray photoelectron spectroscopy, Ruth erford backscattering spectrometry and transmission electron microscop y verified a distinct W/6H-SiC interface after a 2 h vacuum anneal at 1073 K. Current-voltage (I-V) and capacitance-voltage (C-V) measuremen ts were performed at temperatures ranging from 295 to 773 K and reveal ed a low n-type Schottky barrier phi(Bn)(235) = 0.79 eV, ideal for low ohmic applications and a high p-type Schottky barrier phi(Bp)(773) = 1.89 eV. At 473 K a current rectification ratio of 10(7) at +/- 10 V w as observed for the p-type contact.