Micro-Raman measurement of bending stresses in micromachined silicon flexures

Author

Srikar, V.T. ; Swan, Anna K. ; Ünlü, M. Selim ; Goldberg, Bennett B. ; Spearing, S. Mark

Author_Institution

Dept. of Aeronaut. & Astronaut., Massachusetts Inst. of Technol., Cambridge, MA, USA

Volume

12

Issue

6

fYear

2003

Firstpage

779

Lastpage

787

Abstract

Micron-scale characterization of mechanical stresses is essential for the successful design and operation of many micromachined devices. Here we report the use of Raman spectroscopy to measure the bending stresses in deep reactive-ion etched silicon flexures with a stress resolution of ∼10 MPa and spatial resolution of ∼1 μm. The accuracy of the technique, as assessed by comparison to analytical and finite-element models of the deformation, is conservatively estimated to be 25 MPa. Implications for the use of this technique in microsystems design are discussed.

Keywords

Raman spectroscopy; elemental semiconductors; finite element analysis; internal stresses; micromechanical devices; optical microscopy; silicon; stress measurement; Raman shifts; Si; bending stresses; deep reactive-ion etched flexures; finite-element models; micro-Raman spectroscopy; micromachined silicon flexures; micron-scale characterization; microsystem design; stress measurements; Etching; Extraterrestrial measurements; Fabrication; Micromechanical devices; Residual stresses; Silicon; Spatial resolution; Spectroscopy; Stress measurement; Testing;

fLanguage

English

Journal_Title

Microelectromechanical Systems, Journal of

Publisher

ieee

ISSN

1057-7157

Type

jour

DOI

10.1109/JMEMS.2003.820280

Filename

1257355