Arsenic Pressure Dependence of Surface Diffusion of Ga on Nonplanar GaAs Substrates

Abstract

The arsenic pressure dependence of Ga adatom surface diffusion in molecular beam epitaxy (MBE) on nonplanar substrates was investigated. By using in situ scanning microprobe reflection high-energy electron diffraction (µ-RHEED), the distribution of the growth rate of GaAs on the (001) surface near the edge of the (111)A or (111)B sidewall was measured under various arsenic pressures. The surface diffusion length of Ga adatom incorporation on the (001) surface derived from the distribution is on the order of micrometers and it shows a strong dependence on arsenic pressure. A simple model based on one-dimensional surface diffusion was proposed. With this theory, the lifetime of Ga adatom incorporation on other surfaces is obtained.

Characteristics of lateral pn junctions grown on (100) GaAs patterned substrate

“…Diodes passivated with A1GaAs possessed an average ideality factor (q) of 2.8. This is in very good accord with the published figure of r I = 2.7 for AlGaAs-passivated GaAs lateral junctions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. We postulate that extra recombination at the A1GaAs-GaAs boundary could be the cause of the high ideality factor.…”

“…The (4 1 l)A facet was extended during the growth process due to the lateral flux of Ga adatoms directed from the (3 1 l)A to (1 00) surface. This flux is generated by the long Ga adatom lifetime on the (3 1 l)A surface, when compared to the (1 00) surface [13]. Differences in the surface structure of the (4 1 l)A and (3 1 l)A surfaces can be used to explain the silicon doping behaviour.…”

“…At the base of the (3 1 1)A facet, a (1 1 1)A surface developed during growth as the (1 1 1)A surface possessed a higher growth rate than the (3 1 1)A surface [13]. Si-doped (1 1 1)A GaAs is p-type for the growth conditions utilized, so the lower junction is situated at the intersection of the (1 1 1)A and (100) surfaces.…”

Growth kinetics and modeling of selective molecular beam epitaxial growth of GaAs ridge quantum wires on pre-patterned nonplanar substrates

“…6͑b͒ as a function of 23 but it is much larger than 0.7 eV reported by Hata et al 20 and 2.8 eV reported by Ohta et al 24 The difference of E d values seen in those experiments seems to be due to the difference of arsenic pressures during the growth, because the diffusion length of adatoms becomes larger under lower arsenic pressure, as reported by Shen et al 25 The V/III flux ratio used in this study was 30, which was much higher than the V/III ratio of 1 used in the experiment by Ohta et al 24 On the other hand, Van Hove et al 23 used V/III ratio of 10. Thus, the present E d of 4.3 eV seems to represent a value under a high arsenic pressure condition.…”

Growth kinetics and theoretical modeling of selective molecular beam epitaxy for growth of GaAs nanowires on nonplanar (001) and (111)B substrates

“…25 The difference in the value of E d seems to be due to the difference in the arsenic pressure used during growth. This is because the diffusion length of adatoms becomes larger under lower arsenic pressure, as reported by Shen et al 26 The V/III flux ratio used in this study was 30, and this was much larger than the V/III ratio of 1 used in the experiment by Ohta et al 23 On the other hand, Van Hove and Cohen 25 used a V/III ratio of 10. Thus, the present E d of 4.3 eV seems to represent a value under a high arsenic pressure condition.…”