skip to main content

SciTech ConnectSciTech Connect

Title: Step-flow growth mode instability of N-polar GaN under N-excess

GaN layers were grown on N-polar GaN substrates by plasma-assisted molecular beam epitaxy under different III/V ratios. Ga-rich conditions assure step-flow growth with atomically flat surface covered by doubly-bunched steps, as for Ga-polar GaN. Growth under N-excess however leads to an unstable step-flow morphology. Particularly, for substrates slightly miscut towards <1010>, interlacing fingers are covered by atomic steps pinned on both sides by small hexagonal pits. In contrast, a three-dimensional island morphology is observed on the Ga-polar equivalent sample. We attribute this result to lower diffusion barriers on N-polar compared to Ga-polar GaN under N-rich conditions.
Authors:
 [1] ; ; ; ; ;  [1] ;  [2] ; ; ; ; ;  [3]
  1. TopGaN Ltd., Sokołowska 29/37, 01142 Warszawa (Poland)
  2. (Poland)
  3. Institute of High Pressure Physics, PAS, Sokołowska 29/37, 01142 Warszawa (Poland)
Publication Date:
OSTI Identifier:
22218222
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 103; Journal Issue: 7; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; GALLIUM NITRIDES; INSTABILITY; LAYERS; MOLECULAR BEAM EPITAXY; MORPHOLOGY; PLASMA; SEMICONDUCTOR MATERIALS; SPECTROSCOPY; SUBSTRATES; SURFACES