High voltage switching devices and process for forming same

摘要

A microelectronic device structure is disclosed. It comprises:
(a) a first GaN layer having a dopant concentration of not more than about
1 × 1016/cm3;
(b) a second GaN layer overlying said first GaN layer;
(c) a third GaN layer overlying said second GaN layer, said third GaN layer having a dopant concentration of not more than about 1 × 1016/cm3; and
(d) at least one metal contact arranged over said third GaN layer;
further comprising one of the following characteristics (i) or (ii):
(i) the second GaN layer is conductive, and the at least one metal contact forms a metal-to-semiconductor junction with the third GaN layer; or
(ii) the second GaN layer is of n-type conductivity, and a fourth GaN layer of p-type conductivity is disposed between the third GaN layer and the at least one metal contact.