Dielectric Passivation and Edge Effects in Planar GaN Schottky Barrier Diodes

B Orfao,B G Vasallo,T Gonzalez,D Moro-Melgar,J Mateos,M Zaknoune,S Perez

doi:10.1109/ted.2021.3097703

Abstract

The influence of passivation on the edge effects (EEs) present in the capacitance-voltage ( C- V) characteristics of GaN Schottky barrier diodes (SBDs) with realistic geometry is analyzed by means of Monte Carlo simulations. The enhancement of the performance of SBDs as frequency multipliers is based on the optimization of the nonlinearity of the C- V curve, where EEs, strongly influenced by the dielectric passivation of the diode, play a significant role and must be carefully considered. The extra capacitance associated with EEs is affected by the presence of surface charges at the semiconductor/dielectric interface, which is considered by means of a self-consistent model in which the local value of the surface charge is updated according to the surrounding electron density. Our results indicate that, in realistic SBD geometries, a higher dielectric constant of the passivation material leads to more pronounced EEs. The thickness of the dielectric and the lateral extension of the epilayer are also important parameters to be taken into account when dealing with EEs.

Highlights

I N THE last few years, THz technology has advanced significantly, even if difficulties for the development of massive commercial applications in the THz range are still to be solved, mainly related to signal generation
Schottky barrier diodes (SBDs) fabricated on GaAs exhibit an outstanding performance as direct THz detectors and are at the base of the frequency multipliers that allow for fabricating
We have studied how β is affected by the values of several technological parameters, taking as reference diode the one with the geometry and nominal values of the parameters shown in Fig. 1, based on real signal generation. PlanarSchottky barrier diodes (SBDs) fabricated at the Institut d’Électronique de Microélectronique et de Nanotechnologie (IEMN) [15]

Summary

Introduction

I N THE last few years, THz technology has advanced significantly, even if difficulties for the development of massive commercial applications in the THz range are still to be solved, mainly related to signal generation. Schottky barrier diodes (SBDs) fabricated on GaAs exhibit an outstanding performance as direct THz detectors and are at the base of the frequency multipliers that allow for fabricating. Manuscript received May 27, 2021; revised July 13, 2021; accepted July 13, 2021. Date of publication July 26, 2021; date of current version August 23, 2021.

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