Bulk micromachining of a MEMS tunable Fabry-Perot interferometer: effect of residual silicon on device performance

Rohit Srivastava; Urvi Gururaj Shenoy; Scott Forrest; Swetha Chinnayelka; J. Shaikh Mohammed; Ronald S. Besser; Michael J. McShane

doi:10.1117/1.1794707

1 October 2004 Bulk micromachining of a MEMS tunable Fabry-Perot interferometer: effect of residual silicon on device performance

Rohit Srivastava, Urvi Gururaj Shenoy, Scott Forrest, Swetha Chinnayelka, J. Shaikh Mohammed, Ronald S. Besser, Michael J. McShane

Author Affiliations +

Journal of Micro/Nanolithography, MEMS, and MOEMS, Vol. 3, Issue 4, (October 2004). https://doi.org/10.1117/1.1794707

Abstract

A broadband tunable filter for the infrared spectral region is desired for use as a wavelength selective element in a miniature absorption spectrometer. We present the design, fabrication, packaging, and characterization of a bulk micromachined Fabry-Perot interferometer (FPI) for meeting this need. A novel approach to fabricate a MEMS-based tunable resonant cavity using two separate wafers bonded using a "lock-and-key" spacer design is outlined, with the goal of realizing electrostatically actuated membranes from films predeposited on base substrates. This ability could enable the pursuit of MEMS devices without in-house chemical vapor deposition (CVD) capability, after overcoming the shortcomings of bulk micromachining. The FPI device was designed with a planar structure comprising two face-to-face bonded chips of overall lateral dimension 10×10 mm with deflection regions of 2X2 mm. The device employs electrostatic actuation to tune the output wavelength, for which finite element modeling predicted low (<1 V) actuation voltages for movement of the membrane. Experimental results from device testing (mechanical) were found to differ from the theoretical predictions, primarily due to fabrication issues. Specifically, the device performance was found to be greatly influenced by the amount of residual silicon on the wafer chip following inductively coupled plasma (ICP) backside etching, with high voltages (~30 times higher than modeled) required for actuation of the device. Through a combination of modeling and experimental measurements, it is demonstrated that the ability to produce MEMS devices by releasing membranes from films predeposited on substrates is highly susceptible to error in etching and packaging.

©(2004) Society of Photo-Optical Instrumentation Engineers (SPIE)

Citation Download Citation

Rohit Srivastava, Urvi Gururaj Shenoy, Scott Forrest, Swetha Chinnayelka, J. Shaikh Mohammed, Ronald S. Besser, and Michael J. McShane "Bulk micromachining of a MEMS tunable Fabry-Perot interferometer: effect of residual silicon on device performance," Journal of Micro/Nanolithography, MEMS, and MOEMS 3(4), (1 October 2004). https://doi.org/10.1117/1.1794707

Published: 1 October 2004

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available