Details

Autor(en) / Beteiligte

• Gunning, Brendan P.
• Moseley, Michael W.
• Koleske, Daniel D.
• Allerman, Andrew A.
• Lee, Stephen R.

Titel

Phase degradation in BxGa1−xN films grown at low temperature by metalorganic vapor phase epitaxy

Ist Teil von

• Journal of crystal growth, 2017-04, Vol.464, p.190-196

Ort / Verlag

United States: Elsevier B.V

Erscheinungsjahr

2017

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• Using metalorganic vapor phase epitaxy, a comprehensive study of BxGa1−xN growth on GaN and AlN templates is described. BGaN growth at high-temperature and high-pressure results in rough surfaces and poor boron incorporation efficiency, while growth at low-temperature and low-pressure (750–900°C and 20Torr) using nitrogen carrier gas results in improved surface morphology and boron incorporation up to ~7.4% as determined by nuclear reaction analysis. However, further structural analysis by transmission electron microscopy and x-ray pole figures points to severe degradation of the high boron composition films, into a twinned cubic structure with a high density of stacking faults and little or no room temperature photoluminescence emission. Films with <1% triethylboron (TEB) flow show more intense, narrower x-ray diffraction peaks, near-band-edge photoluminescence emission at ~362nm, and primarily wurtzite-phase structure in the x-ray pole figures. For films with >1% TEB flow, the crystal structure becomes dominated by the cubic phase. Only when the TEB flow is zero (pure GaN), does the cubic phase entirely disappear from the x-ray pole figure, suggesting that under these growth conditions even very low boron compositions lead to mixed crystalline phases. •Boron compositions of up to 7.4% in BGaN are achieved at low growth temperatures.•X-ray pole figures and TEM show primarily cubic phase BGaN for high B compositions.•Wurtzite/cubic phase transition occurs for TEB flows around 1%.•Cubic phase persists even for very low B compositions.