Special Section on Reliability, Packaging, Testing, and Characterization of MEMS and MOEMS

Extraction of residual stress and dimensions from electrical measurements on surface micromachined test structures

[+] Author Affiliations
Somashekara Bhat

Indian Institute of Technology Madras, Department of Electrical Engineering, Microelectronics and MEMS Laboratory, Chennai 600036 and Manipal Institute of Technology, Electronics and Communication Engineering Department, Manipal, Karnataka, 576104, India

Enakshi Bhattacharya

Indian Institute of Technology Madras, Department of Electrical Engineering, Microelectronics and MEMS Laboratory, Chennai 600036, India

J. Micro/Nanolith. MEMS MOEMS. 8(3), 031309 (July 10, 2009). doi:10.1117/1.3167825
History: Received November 12, 2008; Revised May 18, 2009; Accepted May 26, 2009; Published July 10, 2009
Text Size: A A A

The deposited thin films in surface micromachining have a lot of residual stress, and it is essential to measure this for both process development and monitoring. We estimate residual stress by electrical measurements on a series of fixed-fixed polysilicon beams designed to deflect laterally due to stress. To minimize errors in estimation during parameter extraction, the device dimensions also have to be measured accurately. Surface micromachining of an oxide-anchored polysilicon cantilever beam can result in beam undercut, reduction in beam thickness, and increase in the gap between the beam and the substrate. The undercut in the beam is estimated from the resonance frequency of the cantilever beam and also by using polysilicon resistors. Final device thickness is obtained by measuring the resistance in fixed-fixed beams.

Figures in this Article
© 2009 Society of Photo-Optical Instrumentation Engineers

Citation

Somashekara Bhat and Enakshi Bhattacharya
"Extraction of residual stress and dimensions from electrical measurements on surface micromachined test structures", J. Micro/Nanolith. MEMS MOEMS. 8(3), 031309 (July 10, 2009). ; http://dx.doi.org/10.1117/1.3167825


Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

Related Journal Articles

Related Book Chapters

Topic Collections

Advertisement
  • Don't have an account?
  • Subscribe to the SPIE Digital Library
  • Create a FREE account to sign up for Digital Library content alerts and gain access to institutional subscriptions remotely.
Access This Article
Sign in or Create a personal account to Buy this article ($20 for members, $25 for non-members).
Access This Proceeding
Sign in or Create a personal account to Buy this article ($15 for members, $18 for non-members).
Access This Chapter

Access to SPIE eBooks is limited to subscribing institutions and is not available as part of a personal subscription. Print or electronic versions of individual SPIE books may be purchased via SPIE.org.