Surface topography evolution and fatigue fracture in polysilicon MEMS structures

Author

Allameh, Seyed M. ; Shrotriya, Pranav ; Butterwick, Alex ; Brown, Stuart B. ; Soboyejo, Wole O.

Author_Institution

Dept. of Mech. & Aerosp. Eng., The Princeton Mater. Inst., NJ, USA

Volume

12

Issue

3

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

313

Lastpage

324

Abstract

This paper presents the results of an experimental study of the micromechanisms of surface topography evolution and fatigue fracture in polysilicon MEMS structures. The initial stages of fatigue are shown to be associated with stress-assisted surface topography evolution and the thickening of SiO₂ layers that form on the unpassivated polysilicon surfaces and crack/notch faces. The differences in surface topography and oxide thickness are characterized as functions of fatigue cycling before discussing the micromechanisms of fatigue fracture.

Keywords

atomic force microscopy; elemental semiconductors; fatigue; micromechanical devices; silicon; surface topography; MEMS structures; Si-SiO₂; crack/notch faces; fatigue cycling; fatigue fracture; micromechanisms; oxide thickness; polysilicon; stress-assisted topography evolution; surface topography evolution; unpassivated surfaces; Fabrication; Fatigue; Manufacturing; Microelectromechanical devices; Microelectromechanical systems; Micromechanical devices; Resonant frequency; Silicon; Surface cracks; Surface topography;

fLanguage

English

Journal_Title

Microelectromechanical Systems, Journal of

Publisher

ieee

ISSN

1057-7157

Type

jour

DOI

10.1109/JMEMS.2003.809957

Filename

1203770