This paper presents an analytical method to calculate residual stress and Young’s modulus in clamped-clamped beams. These types of structures are a typical building block of many MEMS devices, and this guarantees an accurate transferability of the measured parameters. The method is based on the determination of beam bending as a function of applied load by means of a surface profiler, and as a function of beam length. By modeling analytically both the elastic and the stress contribution to beam bending, it is possible to obtain both the stress value and the Young’s modulus by a simple fitting of the experimental data. Results are presented for electrodeposited gold beam arrays of different width, but the method is in principle exploitable for every type of suspended film where the residual stress strongly influences the material properties. Accuracy and limitations of the method are also discussed.
A simple analytical method for residual stress measurement on suspended MEM structures using surface profilometry
Mulloni, Viviana;Colpo, Sabrina;Faes, Alessandro;Margesin, Benno
2013-01-01
Abstract
This paper presents an analytical method to calculate residual stress and Young’s modulus in clamped-clamped beams. These types of structures are a typical building block of many MEMS devices, and this guarantees an accurate transferability of the measured parameters. The method is based on the determination of beam bending as a function of applied load by means of a surface profiler, and as a function of beam length. By modeling analytically both the elastic and the stress contribution to beam bending, it is possible to obtain both the stress value and the Young’s modulus by a simple fitting of the experimental data. Results are presented for electrodeposited gold beam arrays of different width, but the method is in principle exploitable for every type of suspended film where the residual stress strongly influences the material properties. Accuracy and limitations of the method are also discussed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.