Dual-metal gate AlGaN/GaN high electron mobility transistors: A theoretical study

Electrical and Thermal Characteristics of AlGaN/GaN HEMT Devices with Dual Metal Gate Structure: A Theoretical Investigation

“…Moreover, the maximum g m value of the DMG structure devices (0.164 S/mm) is 10.0% higher than that of the SMG structure devices (0.149 S/mm), which is consistent with the experimental results reported by Pinchbeck et al [ 18 ] and Visvkarma et al [ 19 ]. Figure 2 b shows the I D - V DS output characteristics of the DMG structure and SMG structure devices at various V GS ranging from −3 V to 0 V with a step of 1 V. The devices with a DMG structure have a larger saturation output current than the SMG structure devices, which is consistent with the obtained results without accounting for the self-heating effect [ 11 ]. When the self-heating effect is taken into account, the saturation output currents of the DMG and SMG structure devices exhibit a drain current degradation as the drain bias voltage increases, especially at a high V GS .…”

“…Related strategies for controlling the electric field distribution, such as field plate technology [ 8 ] and a dual-metal gate (DMG) structure [ 9 ], have recently been investigated. DMG structures, in particular, can significantly regulate the electric field distribution in the channel, leading to a higher output current in the devices without considering the self-heating effect [ 10 ], as well as suppressing short-channel effects such as drain-induced barrier lowering (DIBL) [ 11 ]. This gate structure, which is made up of two materials with different work functions, is responsible for improving the electrical performance of the devices.…”

Dual metal gate AlGaN/GaN high electron mobility transistors with improved transconductance and reduced short channel effects

“…One approach to improve the device transconductance and suppress DIBL of the lateral HEMTs is to employ a dual metal gate (DMG) structure with different metal work functions (WF) [9][10][11]. Simulations of GaN-based HEMT devices using this structure have been performed previously [12,13] showing notable improvements in the electron velocity under the gate leading to a higher output current and transconductance as well as suppression in the DIBL in these devices [14]. Recently, an improvement in the transconductance of the GaN-based transistors with DMG have been demonstrated experimentally [15,16].…”

Improvement in DC and pulse characteristics of AlGaN/GaN HEMT by employing dual metal gate structure

“…Long et al [11,12] introduced the dual material gate field effect transistor and reported superior device performance on InGaP/InGaAs HFETs. It is well reported that using two different metals at the gate can bring improvement in terms of drain current, transconductance, and reduction of peak electric field [13] and also suppression of drain induced barrier lowering effect was reported using simulations of AlGaN/GaN dual metal gated high electron mobility transistors (DMG-HEMTs) [14].…”

“…To the best of our knowledge only simulation work has been carried out by various groups on AlGaN/GaN based DMG HEMT [13,14] and also only DC simulations results have been published. Pulse IV measurements serve an important characterization technique to qualify for RF performance.…”