Electrical properties of epitaxial 3C- and 6H-SiC p-n junction diodes produced side-by-side on 6H-SiC substrates

Abstract

3C-SiC (/spl beta/-SiC) and 6H-SiC p-n junction diodes have been fabricated in regions of both 3C-SiC and 6H-SiC epitaxial layers which were grown side-by-side on low-tilt-angle 6H-SiC substrates via a chemical vapor deposition (CVD) process. Several runs of diodes exhibiting state-of-the-art electrical characteristics were produced, and performance characteristics were measured and compared as a function of doping, temperature, and polytype. The first 3C-SiC diodes which rectify to reverse voltages in excess of 300 V were characterized, representing a six-fold blocking voltage improvement over experimental 3C-SiC diodes produced by previous techniques. When placed under sufficient forward bias, the SC-SiC diodes emit significantly bright green-yellow light while the 6H SiC diodes emit in the blue-violet. The 6H-SiC p-n junction diodes represent the first reported high-quality 6H-SiC devices to be grown by CVD on very low-tilt-angle (<0.5/spl deg/ off the (0001) silicon face) 6H substrates. The reverse leakage current of a 200 /spl mu/m diameter circular device at 1100 V reverse bias was less than 20 nA at room temperature, and excellent rectification characteristics were demonstrated at the peak characterization temperature of 400/spl deg/C.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>