Sheet‐carrier density and Ⅰ‐Ⅴ analysis of In_(0.7)Ga_(0.3)As/InAs/In_(0.7)Ga_(0.3)As/InAs/In_(0.7)Ga_(0.3)As dual channel double gate HEMT for THz applications

摘要

This paper gives a comprehensive detail about an emerging InAs high electron mobility transistor (HEMT) technology with proper material combination making it suitable for low-power and high-frequency applications. Over the decade, various material combinations were adopted to improve the sheet-carrier density and frequency performances. In this work, we report the performance and optimization of 30-nm gate length InAs-based dual channel double gate (DCDG) HEMT for terahertz application. The dual channel is formed in the device due to the combination of five layers (In0.7Ga0.3As/InAs/In0.7Ga0.3As/InAs/In0.7Ga0.3As) and thus provides a significant improvement in drain current and transconductance. Moreover, the gate scaling with optimized gate to drain-side recess length of gate (L-rd) leads to reduced parasitic (C-gg) and tremendously increases the RF performance metrics f(max) and f(T). For this device, high drain current of 2.203 mA/mu m with peak transconductance of 4.77 mS/mu m is observed. Further optimization of L-rd results in peak f(T) of 810 GHz and f(max) of 900 GHz at a drain source voltage V-ds = 0.5 V. These parameters empower a feasibility of the device for submillimeter as well as terahertz applications.