Organometallic vapor phase epitaxy of GaAs1−xNx alloy layers on GaAs(001): Nitrogen incorporation and lattice parameter variation

Abstract

Epitaxial GaAs1−xNx alloy layers, nominally 200-nm-thick, with x up to 0.0375 were grown on GaAs(001) at temperatures Ts varying from 500 to 650 °C to investigate nitrogen incorporation and lattice parameter variations during organometallic vapor phase epitaxy from trimethylgallium, tertiarybutylarsine, and 1,1-dimethylhydrazine. Quantitative secondary ion mass spectrometry measurements (SIMS) indicate that N incorporation decreases systematically with increasing Ts to become almost negligible at 650 °C. All films are coherent with the substrate as judged by high-resolution x-ray reciprocal lattice mapping although atomic force microscopy and cross-sectional transmission electron microscopy reveal the presence of cracks in films with x>0.02. High-resolution x-ray diffraction measurements combined with SIMS analyses indicate that the lattice constant decreases linearly with increasing x following closely the predictions of Vegard’s rule for x<0.03. At higher concentrations, the lattice constant decreases more rapidly as a significant fraction of N atoms becomes incorporated in nonsubstitutional sites as demonstrated by nuclear reaction analysis.

GaAs1−xNx on GaAs(001): Nitrogen incorporation kinetics from trimethylgallium, tertiarybutylarsine, and 1,1-dimethylhydrazine organometallic vapor-phase epitaxy

“…Combining HR-XRD and SIMS analysis revealed, as reported in Ref. [26], that the lattice constant decreases linearly with increasing x following closely the predictions of Vegard's rule for x up to 0.03. At higher nitrogen concentrations, the lattice constant decreases more rapidly as a significant fraction of N atoms becomes incorporated in non-substitutional sites as demonstrated by nuclear reaction analyses [26].…”

“…SIMS depth profiles also indicate that N concentrations remain constant as a function of depth in all layers with x up to 0.0375 [26].…”

“…All GaAs 1Àx N x layers, irrespective of x and T s , were found to be under tensile strain and fully coherent with their GaAs(0 0 1) substrates as judged by HR-XRD and high-resolution reciprocal lattice mapping [26]. SIMS depth profiles also indicate that N concentrations remain constant as a function of depth in all layers with x up to 0.0375 [26].…”

Oxygen Incorporation in ZnTeO Alloys via Molecular Beam Epitaxy

“…12 As nitrogen is sensitive to nuclear reaction analysis (NRA), channeling NRA provided direct experimental evidence for the identification of such interstitial nitrogen. [13][14][15][16][17] Further study also revealed that the decrease of the interstitial N concentration induced by rapid thermal annealing could result in an increase in carrier concentration and mobility. 18 Compared with N-doped III-V HMAs, there is much poorer understanding of oxygen incorporation in II-VI alloys.…”

“…Substantial efforts have been made to investigate the location of nitrogen dopant in GaAsN HMAs. [12][13][14][15][16][17] In addition to substitutional placement, a considerable fraction of the nitrogen might present as N-N or N-As split interstitials. 12 As nitrogen is sensitive to nuclear reaction analysis (NRA), channeling NRA provided direct experimental evidence for the identification of such interstitial nitrogen.…”