Epitaxial Structure Simulation Study of In_0.53Ga_0.47As/AlAs Double-Barrier Resonant Tunnelling Diodes

Abstract

In this paper, we report about an epitaxial structure simulation study of In0.53Ga0.47As/AlAs double-barrier resonant tunneling diodes (RTD) employing Atlas TCAD quantum transport simulation software developed by SILVACO Inc., which is based on the non-equilibrium Green's function formalism. We analyse how epitaxial layers design impacts the heterostructure static current density-voltage characteristic, including barriers, quantum well (QW), and lightly-doped spacer layers, as well as the employment of a high-bandgap emitter region. Our analysis shows that, while barriers and QW thicknesses have a strong impact on the current density operation of the RTD device, accurate asymmetric spacers design can trade-off between the voltage span and relative position of its negative differential resistance region. This work will guide in optimising the RTD epitaxial structure in order to maximise its RF power performance at low-terahertz frequencies (∼ 100−300 GHz).

A High-Power InP Resonant Tunnelling Diode Heterostructure for 300-GHz Oscillator Sources

“…The proposed n-type intraband epitaxial structure consists of an indium gallium arsenide/aluminium arsenide (In 0.53 Ga 0.47 As/AlAs) double-barrier quantum well (DBQW) structure featuring moderately-thick AlAs barriers (≃ 1.46 nm) and In 0.53 Ga 0.47 As QW (≃ 4.39 nm), asymmetric spacers, and heavily-doped emitter/collector contacts (N D = 5 × 10 19 cm −3 ), grown on top and lattice-matched to a semi-insulating (SI) InP substrate, which was designed through a non-equilibrium Green's function (NEGF)-based quantum transport simulation tool [4] to achieve moderate peak current density J p ∼ 2 mA/µm 2 and large voltage swing ∆V > 1 V [5]. The heterostructure was then investigated through the microfabrication and characterisation of RTD devices.…”

In0.53Ga0.47As/AlAs Double-Barrier Resonant Tunnelling Diodes With High-Power Performance in the Low-Terahertz Band

“…In this paper, we report about a lattice-matched to InP indium gallium arsenide/aluminium arsenide (In 0.53 Ga 0.47 As/AlAs) double-barrier RTD epitaxial structure with high-power performance in the low-terahertz range (∼ 100−300 GHz). Based on the simulation study we reported in [6], we designed and optimised the heterostructure for high-power operation. RTD devices were fabricated and characterised to extract the associated static current density-voltage JV characteristic and small-signal equivalent circuit parameters, from which the high-frequency RF power performance of the heterostructure was investigated.…”