Impact of nanoscale patterning on Schottky contact resistance in AlGaN/GaN Schottky barrier diode

摘要

The improvement of the Schottky contact resistance in an AlGaN/GaN Schottky barrier diode was investigated using dense nanoscale mesa holes. The 100 nm mesa hole array under the Schottky metal added a Schottky contact to the mesa edge with a length of 9.4 mu m/mu m(2). This decreased the contact resistance from 8.23 to 2.55 Omega.mm for a 15 x 100 mu m(2) AlGaN/GaN Schottky contact. Also, the transfer length of 12.5 mu m was reduced to 3.6 mu m by using the mesa array. The nanoscale mesa holes increased the Schottky current and enabled a narrow Schottky contact with high current density. The diode with a 2 x 100 mu m(2) Schottky contact that has mesa holes showed a current of 131 A/mm(2) at 3 V, which is 3.1 times higher than that of a conventional structure. (C) 2018 The Japan Society of Applied Physics