Microwave and power characteristics of AlGaN/GaN/Si high-electron mobility transistors with HfO₂and TiO₂passivation

Abstract

This work presents AlGaN/GaN high-electron mobility transistors (HEMTs) that are grown on silicon. Various passivation layers are deposited on AlGaN/GaN HEMTs. AlGaN/GaN HEMTs were fabricated with TiO 2 dielectrics, and their performance was compared with that of unpassivated and that of HfO 2 -passivated HEMTs. The TiO 2 -passivated HEMT with a gate length of 1 μm exhibits a maximum extrinsic transconductance of 134.4 mS mm −1 , a current-gain cutoff frequency of 10.62 GHz, and a maximum frequency of oscillation of 16.37 GHz. Capping with any of the dielectric materials used herein improves the device performance over that of the unpassivated HEMTs. Additionally, experimental data demonstrate that the use of TiO 2 is a favorable alternative to HfO 2 passivation. This work is the first to present the microwave power of TiO 2 -passivated AlGaN/GaN HEMTs.

Large-Signal Linearity and High-Frequency Noise of Passivated AlGaN/GaN High-Electron Mobility Transistors

“…The GVS value is increased from 1.7 V to 3.2 V at 300 K after TiO 2 passivation. I DS versus V DS at pinch-off conditions and the threshold drain current characteristics at 300 K for the three HEMTs herein were studied [ 11 ]. Figure 5 a plots drain current at V GS = 0 V ( I DSS ) versus temperature of the studied HEMTs.…”

“…The performance of AlGaN/GaN HEMT technology is limited by charge trapping effects. Consequently, various candidates for passivation has been attempted to neutralize the net surface charge arising from the combination of surface states and the polarized barrier [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ]. Most works focus on the performance of the passivated AlGaN/GaN HEMTs at room temperature.…”

“…Most works focus on the performance of the passivated AlGaN/GaN HEMTs at room temperature. The room-temperature characteristics of AlGaN/GaN HEMT with HfO 2 and TiO 2 passivation were reported [ 11 ]. However, AlGaN/GaN heterostructure is a promising material system for high-temperature electronics.…”

Reactive evaporation of SiOx films for passivation of GaN high-electron-mobility transistors

“…Therefore, strong interest has been directed towards development of passivation materials and processes in the past decade. Besides conventional passivation materials such as SiNx and SiO2 [9], other dielectrics like SiON [9,10], Al2O3 [11][12][13][14], HfO2 [15][16][17], Sc2O3 [18,19], and MgO [18,20] prepared by plasma-enhanced chemical-vapour deposition (PECVD), sputtering, atomic-layer deposition (ALD), molecular-beam epitaxy (MBE) etc. have been studied.…”

Comprehensive characterization of AlGaN/GaN metal‐oxide‐semiconductor high‐electron mobility transistors with TiO2 gate dielectric

“…1 Introduction Many superior devices has been presented in the past several years, such as heterojunction bipolar transistors (HBTs) [1], heterostructure field-effect transistors (HFETs) [2][3][4][5][6], and metal-insulator semiconductor heterostructure field effect transistor (MISHFET) [7][8][9][10][11][12][13][14][15][16][17][18]. III-nitrides are attractive candidates for power applications such as power switching devices and RF power amplifiers.…”