P-type 6H-SiC photoconductive switches

Abstract

Summary form only given. Photoconductive techniques were to measure both the surface and bulk carrier lifetimes in p-type 6H-SiC. In order to separate the surface and bulk material properties, both lateral and vertical switches were used. Measurements were made with both a N/sub 2/ laser and an N/sub 2/-pumped dye laser as the optical source, which permitted investigation of the switch behavior both above and just below the 6H-SiC absorption edge. The photovoltaic and photoconductive effects were measured for both switch geometries and at several wavelengths near the 6H-SiC absorption edge. Although the devices possess dark resistances on the order of 10 /spl Omega/, the switching efficiency of the vertical switches approached 32 percent, while the resistance of the lateral devices could be reduced by 50 percent with 200 /spl mu/J of laser radiation at /spl lambda/ = 337 nm.