Technology and Performance of InAlN/AlN/GaN HEMTs With Gate Insulation and Current Collapse Suppression Using Zr$\hbox{O}_{\bm 2}$ or Hf $\hbox{O}_{\bm 2}$

Abstract

We present the technology and performance of InAlN/AlN/GaN MOS HEMTs with gate insulation and surface passivation using Zr or Hf . About 10-nm-thick high- dielectrics were deposited by MOCVD before the ohmic contact processing. Plasma pretreatment allowed the reduction of the temperature of the ohmic contact annealing at 600degC. The insulation and passivation of 2-m gate-length MOS HEMTs lead to a gate leakage current reduction by four orders of magnitude and a 2.5 increase of the pulsed drain-current if compared with a Schottky barrier (SB) HEMT. A dc characterization shows 110 mS mm transconductance and 0.9 A mm drain--currents that represent improvements in comparison to the similar SB HEMT and that is explained by a mobility-dependent carrier depletion effect.