DocumentCode :
2651112
Title :
Simulation of the effect of surface roughness on the mechanical properties of a microbeam
Author :
Fang, Wen-Xiao ; Huang, Qin-Wen ; Liu, Xin ; Qiu, Chu-Xuan
Author_Institution :
Sci. & Technol. on Reliability Phys. & Applic. of Electron. Component Lab., Guangzhou, China
fYear :
2011
fDate :
17-19 June 2011
Firstpage :
1000
Lastpage :
1003
Abstract :
Surface flaw is harmful for the quality of microelectromechanical device, because it could affect the mechanical response of the micro structure inside. In this paper, we simulate the effect of surface roughness on the mechanical properties of a micro beam by a two-dimensional finite element analysis. The random surface is generated in one dimension by a gauss correlation function with two major parameters, root mean square (RMS) s and correlation length λ. The effect of s and λ on the bending deflection and eigenfrequency of a 0.5μm (height)×5μm (length) beam is investigated for the cases of one fixed end and two fixed ends, with the following results. Firstly, with a same load, the bending deflection of the microbeam increases with both RMS and correlation length, while the eigenfrequencies (the first to the sixth) of the microbeam decrease with the increase of both RMS and correlation length. In another word, the roughness of the surface softens the microbeam. Secondly, by generating numbers of microbeams with a same s and λ, we find that the increase of the s and λ causes the increasing instability degree of the microbeam for the bending deflection Umax and the eigenfrequencies ω in both cases. In the case of two fixed ends, a RMS of 60nm and a correlation length of 300nm lead to a ΔUmax/Umax=7% instability degree of the bending, while in the case of one fixed end, they would lead to a value of ΔUmax/Umax=11%. In the mean time, they lead to Δω/ω=2.9% instability degree of the first frequency in the case of two fixed ends, and Δω/ω=4.25% in the case of one fixed end. The simulation would be helpful in the fabrication design of microelectromechanical device.
Keywords :
beams (structures); bending; finite element analysis; surface roughness; RMS; bending deflection; correlation length; eigenfrequency; mechanical properties; microbeam; root mean square; size 300 nm; surface roughness; two-dimensional finite element analysis; Correlation; Rough surfaces; Silicon; Surface morphology; Surface roughness; Surface topography; Surface treatment; bending deflection; eigenfrequencies; microbeam; surface roughness;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Quality, Reliability, Risk, Maintenance, and Safety Engineering (ICQR2MSE), 2011 International Conference on
Conference_Location :
Xi´an
Print_ISBN :
978-1-4577-1229-6
Type :
conf
DOI :
10.1109/ICQR2MSE.2011.5976772
Filename :
5976772
Link To Document :
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