Raman spectroscopy of epitaxial Si/Si1-xGex heterostructures

被引：7

作者：

Liu, R ^{[1
]}

Zollner, S ^{[1
]}

Liaw, M ^{[1
]}

O'Meara, D ^{[1
]}

Cave, N ^{[1
]}

机构：

[1] Motorola Inc, Arizona Technol Labs, Mesa, AZ 85202 USA

来源：

EPITAXY AND APPLICATIONS OF SI-BASED HETEROSTRUCTURES | 1998年 / 533卷

关键词：

D O I：

10.1557/PROC-533-63

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

Raman scattering studies were carried out on epi Si/Si1-xGex (x = 0.1 to 0.3) heterostructures consisting of a thin Si cap layer (100 - 400 Angstrom) a grade-down Si1-xGex layer, a constant Si1-xGex buffer layer and a grade-up graded Si1-xGex layer on (100) oriented Si substrates. Different Ge composition, Si1-xGex layer thicknesses and thermal treatment were used to achieve different relaxation in the Si1-xGex layers. It has been revealed that, to a very good approximation, the absolute strains in the cap Si and constant Si1-xGex layers follow a simple sum-rule that is imposed by the lattice mismatch between unstrained Si and completely relaxed Si1-xGex. This sum rule can be used to determine the Ge composition and stresses in both cap Si and constant Si1-xGex layers. Excellent agreement was found between the theoretical curve obtained with LO phonon strain coefficient b=-930cm(-1) and the experimental total strain for all samples, regardless of the degree of the relaxation of the grade-up Si1-xGex layer.

引用

页码：63 / 68

页数：6