Effect of stress voltage on the dynamic buffer response of GaN-on-silicon transistors

Abstract

Back-gated measurements on conductive silicon substrates have been performed to investigate the effect of stress voltage on the dynamic behaviour of GaN-on-silicon (GaN-on-Si) transistors. Two comparable samples were studied with the only difference being the vertical dislocation density. Results show a clear correlation between dislocation density and the ability of the GaN buffer to dynamically discharge under high stress conditions.

Probing the effect of point defects on the leakage blocking capability of Al0.1Ga0.9N/Si structures using a monoenergetic positron beam

“…Threading dislocations have been suggested to play a dominant role in the breakdown process of C-doped GaN. 8,11,49 The dislocations provide leakage current paths and electron transfer can occur via a trap-assisted tunneling processes. 50 According to Fig.…”

“…[7][8][9][10][11][12] According to the density functional theory, 13,14 C in GaN is an amphoteric dopant, and C substituting N (C N ) acts as a deep acceptor. A high concentration of C (!…”

Lateral Charge Transport in the Carbon-Doped Buffer in AlGaN/GaN-on-Si HEMTs

“…Fig. 1(c) shows the lumped-element representation of the device structure including the primary vertical leakage paths and capacitances normally used to interpret substrate bias experiments assuming 1D conduction [11,[13][14][15][16][17][18][19]. Only negative substrate bias, VSUB, is considered here since this corresponds to the polarity experienced under the drain in a transistor under OFF state conditions.…”

“…Substrate bias experiments provide an excellent tool to study charge trapping and transport in the buffer and effectively distinguish surface and bulk induced current collapse [14][15][16]. Monitoring the substrate bias dependence of the channel conductivity, and its dispersion as the ramp-rate and temperature are varied, allowed a model for the transport within each layer within the buffer to be constructed [13,[17][18][19]. Substrate bias ramps have been used to link buffer leakage in the upper part of the epitaxy to dynamic RON dispersion [20,21].…”

X‐Ray Diffraction Microstrain Analysis for Extraction of Threading Dislocation Density of GaN Films Grown on Silicon, Sapphire, and SiC Substrates

“…Notwithstanding their qualities, GaN on silicon substrates is highly defective and stressed, with high densities of threading dislocations (TDs) observed in these materials, usually in the range of 10 8 –10 10 cm −2 . Different concentrations of TD have been shown to affect the performance of GaN‐on‐Si‐based devices, especially their dynamic behavior, and the study of their density is therefore essential to understand the device performance.…”