Evidence of hydrogen diffusion in n-type GaN

TL;DR

This paper reports the first observation of hydrogen outdiffusion in bulk crystalline GaN and measures its diffusion coefficient at 1045°C, providing insights into impurity behavior in nitride semiconductors.

Contribution

It presents the first experimental evidence of hydrogen diffusion in GaN and quantifies its diffusion coefficient at a standard growth temperature.

Findings

Hydrogen outdiffuses from bulk GaN.

Hydrogen diffusion coefficient determined at 1045°C.

Implications for impurity control in GaN-based devices.

Abstract

The control over impurities like hydrogen and oxygen is of key importance in nitride-based semiconducting due to their unrivaled applicability in optoelectronics and high power/high frequency electronics. Therefore, it is desirable to continue the research on its diffusion and segregation in semiconductor materials. In this work, we report on a first observation on hydrogen outdiffusion from bulk crystalline gallium nitride. The extent of the hydrogen diffusion is established by secondary ion mass spectrometry. Analysis of characteristic hydrogen profile in GaN grown using ammonothermal method, led to the determination of the hydrogen diffusion coefficient at the temperature of 1045C - a standard growth temperature for HVPE (halide vapor phase epitaxy) method.