Realization of Insulating Buffer Layers via MOCVD-Grown Nitrogen-Doped (010) \b{eta}-Ga2O3

TL;DR

This paper demonstrates that nitrogen-doped ta-Ga2O3 buffer layers grown via MOCVD can effectively replace HF treatment to eliminate interfacial silicon, improving the insulating properties at the substrate-epitaxial interface.

Contribution

It introduces a controllable in-situ nitrogen doping method to create effective insulating buffer layers, replacing traditional chemical treatments for interface silicon removal.

Findings

Nitrogen-doped layers with ta-Ga2O3 are fully insulating at NH3 flow rates  1200 sccm.

A 50 nm thick nitrogen-doped buffer layer effectively mitigates interfacial silicon.

In-situ doping provides a controllable alternative to chemical etching for interface engineering.

Abstract

We present MOCVD-grown, nitrogen-doped \b{eta}-Ga2O3 films as an insulating buffer layer on Fe-doped (010) \b{eta}-Ga2O3 substrates in lieu of 49% HF treatment to remove unintentional silicon at the substrate-epitaxial layer growth interface. N-doped layer thickness and NH3 flow were systematically varied to experimentally determine the lowest nitrogen concentration and thickness of the buffer layer needed to fully compensate the interfacial silicon peak. The NH3 molar flow rate was varied from 200 sccm to 1800 sccm. Results showed fully insulating N-doped layers for samples with NH3 flow rates greater than or equal to 1200 sccm and a thickness of 50 nm. This study demonstrates the efficacy of in-situ, controllably doped nitrogen buffer layers as a mitigation method for unintentional interfacial silicon at the substrate-epitaxial layer growth interface.