Optimization of ICPCVD Amorphous Silicon for Optical MEMS Applications

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

© 1992-2012 IEEE. In this paper, we present the optimization of optical and mechanical properties of inductively coupled plasma chemical vapor deposited (ICPCVD) amorphous silicon thin films for fabrication of high-quality optical microelectromechanical systems-based devices operating from visible to short-wave infrared wavelengths (450-3000 nm). Our results indicate that, at relatively high deposition temperatures for plasma CVD, a decrease in the ICP power results in films with lower tensile stress, higher refractive index, and lower extinction coefficient. We show that hydrogen concentration alone is not a sufficient parameter for controlling optical and mechanical quality of the films. In particular, both the hydrogen concentration and the hydrogen-silicon bonding nature together play a vital role in determining the optical and the mechanical quality of the silicon thin films. As a demonstration vehicle, three layer silicon-silicon oxide-silicon-based distributed Bragg reflectors were fabricated for the visible (500-700 nm), near infrared (700-1000 nm), and short-wave infrared (2000-3000 nm) wavelength ranges using an optimized silicon fabrication recipe. The measured optical transmission spectra show close to 90% peak reflectivity. Finally, stress optimization was evaluated by fabricating 270-μm diameter circular suspended silicon membranes, which demonstrate a flatness variation on the order of
Original languageEnglish
Pages (from-to)1998-2007
JournalJournal of Microelectromechanical Systems
Volume24
Issue number6
DOIs
Publication statusPublished - 2015

Fingerprint Dive into the research topics of 'Optimization of ICPCVD Amorphous Silicon for Optical MEMS Applications'. Together they form a unique fingerprint.

Cite this