Substrate temperature dependence of arsenic precipitate formation in AlGaAs and GaAs
作者:
K. Mahalingam,
N. Otsuka,
M. R. Melloch,
J. M. Woodall,
A. C. Warren,
期刊:
Journal of Vacuum Science&Technology B: Microelectronics and Nanometer Structures Processing, Measurement, and Phenomena
(AIP Available online 1991)
卷期:
Volume 9,
issue 4
页码: 2328-2332
ISSN:1071-1023
年代: 1991
DOI:10.1116/1.585742
出版商: American Vacuum Society
关键词: GALLIUM ARSENIDES;ALUMINIUM ARSENIDES;LAYERS;MOLECULAR BEAM EPITAXY;ARSENIC;TEMPERATURE DEPENDENCE;HIGH TEMPERATURE;ANNEALING;GaAs;(AlGa)As
数据来源: AIP
摘要:
GaAs epilayers which are grown by molecular‐beam epitaxy under ‘‘normal’’ group III–V fluxes but at very low substrate temperatures contain as much as 1% excess arsenic. Upon annealing these epilayers at a temperature of 600 °C, the excess arsenic forms precipitates. We have undertaken a systematic study of the substrate growth temperature dependence of this incorporation of excess arsenic in both GaAs and Al0.3Ga0.7As epilayers. The substrate growth temperature was varied in increments of 25 °C from 225 to 375 °C after every 0.25 μm of film growth for a GaAs and an Al0.3Ga0.7As epilayer. Both epilayers were grown using a dimer arsenic source and a group V to total group III beam equivalent pressure ∼20. After growth the films were annealed for 1 h in the As2flux at a temperature of 600 °C. Cross‐sectional samples were than prepared by the ion thinning technique and examined by transmission electron microscopy (TEM). Both epilayers contained arsenic precipitates; this is the first observation of arsenic precipitates in an Al0.3Ga0.7As epilayer. The density of the arsenic precipitates in the two epilayers had a strong dependence on substrate growth temperature. Details of the film growth and of the TEM observations are reported.
点击下载:
PDF
(563KB)
返 回