Experimental and Theoretical Investigation of Collector Spacer and Doping Profile on Triple‐Barrier Resonant Tunneling Diodes

Abstract

Upcoming THz applications require compact, robust, and efficient sources with high output‐power. Among electronic devices, resonant tunneling diodes (RTDs) have been shown to be a promising candidate for THz operation. Triple barrier resonant tunneling diodes provide a high degree of design and operation freedom. Zero‐bias detection and THz emission is possible with the same device due to the asymmetric structure and IV curve. However, more investigations in the layer stack design are required. We present an investigation into the effect of collector spacer thickness and doping profile in the subcollector contact region. The aim is to simultaneously optimize the RF output‐power and cut‐off frequency in triple barrier structures. A series of devices with different collector spacers and two distinct doping profiles are fabricated. We observe a trade‐off between collector spacer thickness and doping profile for either higher output‐power or cut‐off frequency. In addition, we present simulation results from a Non‐Equilibrium Green’s Function solver implemented in Python. Here, we observe a need for accurate determination of the extent of the non‐equilibrium region to achieve simulation results matching the IV measurements.This article is protected by copyright. All rights reserved.