Raman study under resonant conditions of defects near the interface in a GaAs/Si heterostructure
作者:
A. Mlayah,
R. Carles,
G. Landa,
E. Bedel,
C. Fontaine,
A. Mun˜oz‐Yagu¨e,
期刊:
Journal of Applied Physics
(AIP Available online 1990)
卷期:
Volume 68,
issue 9
页码: 4777-4781
ISSN:0021-8979
年代: 1990
DOI:10.1063/1.346133
出版商: AIP
数据来源: AIP
摘要:
A Raman study has been performed, under resonant conditions, on a GaAs bevelled‐edge layer grown on a Si substrate to characterize the optical and crystalline properties of the epilayer near the interface. According to the geometrical characteristics of the sample, a theoretical expression for the Raman intensities profile has been established and compared to the experimental data. This fitting procedure enables us to investigate the absorption coefficient of the GaAs layer due to the disorder‐induced softening of theE1edge. A quantitative analysis of the lattice disorder has been carried out on both longitudinal and transverse optical modes by studying the Raman line‐shape evolution versus the laser spot position on the bevel edge. From this study, we have followed the recovery of the crystalline quality of the epilayer while going away from the interface, and evaluated the ‘‘Raman thickness’’ of the dislocated layer. Using the spatial correlation model as a relationship between the disorder amount and the outcoming effects on the Raman line peaks, we have estimated the dislocation density at the heterostructure interface.
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