Hostname: page-component-cd9895bd7-dk4vv Total loading time: 0 Render date: 2024-12-29T14:13:48.267Z Has data issue: false hasContentIssue false
  • English
  • Français

Finite Element Analysis of Elastic and Plastic Deformation during Growth of Si1−xGex/Si Heterostructures

Published online by Cambridge University Press:  17 March 2011

F. Sahtout Karoui ,
A. Karoui  and
G. Rozgonyi
F. Sahtout Karoui
Affiliation:
Materials Science and Engineering Department, North Carolina State UniversityRaleigh, NC 27695-7916, USA
A. Karoui
Affiliation:
Materials Science and Engineering Department, North Carolina State UniversityRaleigh, NC 27695-7916, USA
G. Rozgonyi
Affiliation:
Materials Science and Engineering Department, North Carolina State UniversityRaleigh, NC 27695-7916, USA
Get access

Abstract

The elastic and plastic stress distribution in strained Si1−xGex heterostructure (x=0.2 and x=0.5), was investigated during the growth process using a nonlinear transient finite element modeling. The material plastic behavior is described by the von Mises yield criteria coupled with isotropic work hardening conditions. The calculated stress distribution during growth of the SiGe cap layer shows that the von Mises stress fluctuates strongly within the layers and at the interfaces. The surface of constant composition Si1−xGex layer is found under compressive stress in both cases. Within that layer the normal stress in the growth direction remains compressive for x=0.2, while it changes from compressive to tensile for x=0.5. In the graded layer the stress goes from tensile to compressive for x=0.5 and in the opposite way for x=0.2. High plastic deformation is observed in the layers, with the maximum von Mises plastic stress being higher for x=0.5 and localized in the SiGe graded region. The plastic strain vanishes monotonically up to 8 μ deep into the Si bulk substrate, in agreement with TEM images that revealed dislocation loops penetrating into the substrate. The time dependent analysis shows that elastic and plastic deformation appear almost instantaneously in the sublayers, while in the Si substrate it is delayed up to 300 s.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 824: Symposium CC – Scientific Basis for Nuclear Waste Management XXVIII , 2004 , P3.39.1
Copyright
Copyright © Materials Research Society 2004

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Ismail, K., Arafa, M., Saenger, K. L., Chu, J. O., and Meyerson, B. S., Appl. Phys. Lett., 66(9), 1077 (1995).Google Scholar
2. Kasper, E., Properties of Strained and Relaxed Silicon Germanium, EMIS Datareviews Series No. 12, INSPEC (1995)Google Scholar
3. Vasiliev, V. V., Morozov, E. V., Mechanics and Analysis of Composite Materials, Elsevier (2001).Google Scholar
4. Schroter, W., Brian, H. G., Siethoff, H., J. Appl. Phys., 54(4), 1816 (1983).Google Scholar
5. Lowney, D. et al. , Semicond. Sci. Technol. 17, 1081 (2002).Google Scholar
6. Currie, M. T., Samavedam, S. B., Langdo, T. A., Leitz, C. W., and Fitzgerald, E. A., Appl. Phys. Lett., 72 (14), 1718 (1998).Google Scholar
7. Bray, K. et al. , Interfaces in Electronic Materials Symposium, ECS meeting, October 2003, Orlando, FL. Google Scholar