GaN Schottky rectifiers have been fabricated on free-standing substrates an
d on epi/substrate structures. Forward turn-on voltages were as low as 3 V
at 25 degreesC. Reverse recovery was complete in <600 ns; with a characteri
stic time constant of <similar to>163 ns. The temperature coefficient For r
everse breakdown voltage (V-B) was -2.5 +/- 0.6 V K-1 which is much lower t
han for lateral rectifiers reported previously, where values up to -30 VK-1
were achieved. Reverse currents increased with rectifying contact diameter
and V-B decreased with increasing contact size, The best on-state resistan
ce was 20.5 m Omega cm(-2) for diodes with V-B =450 V, producing a figure-o
f-merit (YB)(2)/R-ON of similar to 10 MW cm(-2). (C) 2001 Elsevier Science
Ltd. All rights reserved.