Electrooptical characterization of new classes of silicon carbide UV photodetectors

Abstract

In this paper, we present the fabrication process steps and the characterization of 4H-SiC vertical Schottky UV detectors, where interdigitated strips, acting as top metal contacts, have been realized in Ni2Si. These devices exploit the pinch-off surface effect. I-V and C-V characteristics, as functions of temperature, were measured in dark conditions. In addition, we have carried out responsivity measurements, for wavelengths ranging from 200 to 400 nm, at varying package temperature and applied reverse bias. A comparison among devices having different strip pitch sizes has been performed, thus finding out that the 10-μm pitch class demonstrates the top performances as regards the tradeoff between exposed surface area and complete merge of adjacent depleted regions under top contacts.