  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.
