STM Journals Peer-reviewed research from Consortium e-Learning Network

Journal of Semiconductor Devices and Circuits

DC and RF Analysis on Specific Quantum-Well Heterostructures

  1. Subhadeep Mukhopadhyay

Abstract

Polarization-graded AlGaN back-barrier nano-layer is introduced in high electron mobility transistor (HEMT) structure to have an improved drain current characteristics and better radio-frequency performance, using two-dimensional drift-diffusion simulation by SILVACO-ATLAS physical simulator. In this work, the AlGaN/AlN/GaN/AlGaN/GaN double heterojunction HEMT structure is optimised with graded back barrier layer to study the DC and RF performances. Investigation of this structure with graded back barrier layer is the novelty of this work. According to the effect of gate length on drain current, higher drain current corresponds to shorter gate length in both graded and non-graded HEMT structures. Variations in transconductance are investigated in both graded and non-graded HEMT structures. Formation of quantum wells due to conduction band discontinuity is directly demonstrated in both graded and non-graded HEMT structures using the physical simulator. The conduction band discontinuity is 2.38 eV for graded HEMT structures as higher than non-graded HEMT structures, resulting into better carrier confinement. According to the simulation results, radio-frequency performance is better in graded HEMT structures than non-graded HEMT structures.

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