ABSTRACT
A detailed investigation was carried out on facet formation in the metalorganic molecular beam epitaxy (MOMBE) of GaAs on a mesa-etched (100) GaAs substrate by in situ scanning microprobe reflection high-energy electron diffraction (μ-RHEED) in real time. The distribution of the growth rates on the (100) surface near the edge of the mesa-groove was also measured by μ-RHEED. Besides the initial (100) surface and a (111)A sidewall, a (411)A facet as well as (311)A and ( 5 11 ¯ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq10.tif"/> A facets were formed at the lower and upper sidewalls, respectively, at growth temperatures between 540 and 620 °C. It was found that the formation of the ( 5 11 ¯ ) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781003069638/440efdcf-c2ed-414a-bdad-7c98e059177f/content/eq11.tif"/> A and (411)A facets is substantially associated with the exponential variation of the growth rate on the (100) surface, due to the flow of either Ga adatoms or Ga compounds from the sidewall to the (100) surface of the mesa pattern.
