arXiv subjects

Adam Barcz

Publications and source records attributed to Adam Barcz.

3 recordsLinked to original sources

arXiv2020

Evidence of hydrogen diffusion in n-type GaN

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.

cond-mat.mtrl-sci↗

arXiv2020

Diffusion of Be in gallium nitride: Experiment and modelling

Diffusion mechanism of beryllium in gallium nitride was investigated by analyzing temperature-dependent diffusion profiles from an infinite source. Beryllium atoms were implanted into a high structural quality gallium nitride layer crystallized by halide vapor phase epitaxy on an ammonothermal gallium nitride substrate. Post-implantation annealing was performed at different temperatures, between 1000{\deg}C and 1400{\deg}C, under high nitrogen pressure. Beryllium profiles were analyzed in the as-implanted and annealed samples by secondary ion mass spectrometry. It was shown that the diffusion of the dopant results from the combination of two mechanisms: rapid interstitial and slow interstitial-substitutional diffusion. The pre-exponential factor as well as activation energy for both diffusion paths were determined. Moreover, from the characteristic features of beryllium depth profiles, the formation energies of gallium vacancy and beryllium in interstitial position were calculated and compared to the theoretical values.

cond-mat.mtrl-sci↗

arXiv2018

Diffusion of Mn in gallium nitride: Experiment and modelling

The control over the structural homogeneity is of paramount importance for ternary nitride compounds - the second most important semiconducting material-class after Si, due to its unrivalled applicability in optoelectronics, and high power/high frequency electronics. Therefore it is timely to investigate possible mechanisms influencing the crystallographic constitution of the material. In this work the diffusion mechanism of manganese in gallium nitride is investigated in two types of epilayers: Mn implanted metalorganic vapour phase epitaxy grown GaN and (Ga,Mn)N solid solution grown by molecular beam epitaxy. The extent of the Mn diffusion is established by secondary ion mass spectrometry. Analysis of the Mn profiles in the implanted samples in the frame of the infinite source diffusion led to the establishment for the first time of the pre-exponential factor DO = 2x10-4 cm2/s and diffusion activation energy EA = 1.8 eV describing the diffusion coefficient of Mn in GaN. Modelling of the out-diffusion of Mn from (Ga,Mn)N layers based on these values in turn allows to provide an explanation of the origin of the ubiquitously observed near-the-surface sizable depletion of Mn in (Ga,Mn)N, resulting from the blocking of the Mn out-diffusion by Mn-oxide and the correspondingly formed space-charge layer on the surface.

cond-mat.mtrl-sci↗