Off‐state breakdown in InAlN/AlN/GaN high electron mobility transistors

Abstract

Unpassivated InAlN/AlN/GaN high electron mobility transistors off‐state breakdown is analyzed for different gate‐to‐drain distances. The breakdown voltage linearly increases with the gate to drain distance reaching 350 V for a 10 μm contact separation; the sub‐threshold leakage current is < 10–5 A/mm. Similar breakdown voltages and leakage current are obtained on GaN buffer for two Ohmic contacts if their distance is the same. It is suggested that the breakdown is governed by injection/avalanche processes in the GaN buffer layer and is basically not affected by InAlN barrier. Our conclusions are further supported by measuring all currents in the three‐terminal configuration of the transistors before and during the breakdown and by using a drain current injection technique. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Current Stability in Multi-Mesa-Channel AlGaN/GaN HEMTs

“…As the L GD increased, the V knee increased and the I-V slope in the linear region decreased. This is typical in planar-type AlGaN/GaN HEMTs [35,36]. The planar device also exhibited pronounced current decrease in the high drain bias region.…”

High Voltage InAlN/GaN HFETs Achieved by Schottky-Contact Technology for Power Applications

“…In the proposed devices, the breakdown of the devices is dominated and induced by the gate-drain leakage instead of the source-drain leakage which has been observed in conventional InAlN/GaN HFETs (6). During the three-terminal off-state breakdown measurement the source leakage (I S,leakage ) is consistently lower than the drain leakage (I D,leakage ) for the proposed devices.…”

“…It is obvious that the BV of the InAlN/GaN HFETs were significantly improved by using the Schottky contact technology while paying a moderate cost in R on,sp compared with the conventional HFETs. The performance of the proposed devices is much better than the reported InAlN/GaN HFETs (6,7). The Schottky-Source HFETs exhibit almost a linear R on,sp -BV dependence as shown in Fig.…”

“…The breakdown of the SSD HFETs is dominated and induced by the gate leakage (see Fig. 2) instead of the source leakage as reported in (6). The source leakage of the SSD HFETs exhibits negligible increase during the high voltage measurement, which is a result of the effective suppression of the source carrier injection realized by using the Schottky contact in the source area.…”

Control of plasma-CVD SiO2/InAlN interface by N2O plasma oxidation

“…13) Therefore, the use of an insulator for the gate structure is necessary. So far, several insulators, i.e., Al2O3 12,[14][15][16][17][18] , ZrO2 15,19,20) , GdScO3 15) , HfO2 19) , SiO2 21) , plasma oxides [22][23][24][25][26] , and thermal oxides 27,28) , have been used to construct insulated gate HEMTs or metal-insulator-semiconductor (MIS) HEMTs. Among these insulators, SiO2 has the widest band gap, achieving a large ΔEC with InAlN lattice-matched to GaN.…”