In:
Japanese Journal of Applied Physics, IOP Publishing, Vol. 32, No. 12R ( 1993-12-01), p. 5479-
Abstract:
We study temporal evolutions of surface anisotropy change detected optically at wavelengths of 633 nm and 488 nm during the formation of Ga-stabilized surfaces to characterize As-stabilized (001) GaAs surfaces grown by metalorganic chemical vapor deposition (MOCVD). Using the evolution of Ga dimer concentration, we find that effective As coverages, which are defined as the amount of As on the surface that can be incorporated into the crystal, are close to 1 for the c(4×4) surface and As-richer surfaces, although these surfaces have actual As coverages of more than 1. We also find that three kinds of well-defined As-stabilized surfaces with different As coverages, c(4×4)+α, c(4×4), and (2×4), can exist in MOCVD environments depending on the AsH 3 partial pressures, with c(4×4)+α being a c(4×4)-like surface with additional As. A fast As desorption with a time constant of 〈 0.5 s at 600°C and at 570°C accompanies the conversion from c(4×4)+α to c(4×4). Another As desorption with a time constant of 2 s at 600°C and 4 s at 570°C accompanies the conversion from c(4×4) to the least-As-rich (2×4) surface with θ As =0.6-0.7.
Type of Medium:
Online Resource
ISSN:
0021-4922
,
1347-4065
DOI:
10.1143/JJAP.32.5479
Language:
Unknown
Publisher:
IOP Publishing
Publication Date:
1993
detail.hit.zdb_id:
218223-3
detail.hit.zdb_id:
797294-5
detail.hit.zdb_id:
2006801-3
detail.hit.zdb_id:
797295-7
