Title :
Ultra-high aspect ratio trenches in single crystal silicon with epitaxial gap tuning
Author :
Ng, Eldwin Jiaqiang ; Chiang, C.-F. ; Yang, Yi ; Hong, Vu A. ; Ahn, Chong H. ; Kenny, Thomas W.
Author_Institution :
Dept. of Mech. Eng., Stanford Univ., Stanford, CA, USA
Abstract :
A new method for the formation of narrow (<;100nm), smooth, ultra-high aspect ratio (>500:1) trenches in monocrystalline silicon is demonstrated using a combination of deep reactive ion etching (DRIE) and epitaxial deposition. Aspect ratios achieved were an order of magnitude higher than using DRIE only. This method was used to fabricate width-extensional mode resonators with narrow gaps within our wafer-scale epitaxial polysilicon encapsulation process. A representative 52 MHz width-extensional mode resonator with a motional impedance near 1 KΩ is carefully characterized.
Keywords :
UHF resonators; elemental semiconductors; epitaxial layers; isolation technology; microfabrication; silicon; sputter etching; Si; deep reactive ion etching; epitaxial deposition; epitaxial gap tuning; frequency 52 MHz; monocrystalline silicon; motional impedance; single crystal silicon; ultra-high aspect ratio trenches; wafer-scale epitaxial polysilicon encapsulation process; width-extensional mode resonators; Crystals; Epitaxial growth; Etching; Micromechanical devices; Silicon; Tuning; Deep Reactive Ion Etching; Epitaxial Deposition; High Aspect Ratio; Narrow Gaps; Resonators; Silicon Trenches;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS & EUROSENSORS XXVII), 2013 Transducers & Eurosensors XXVII: The 17th International Conference on
Conference_Location :
Barcelona
DOI :
10.1109/Transducers.2013.6626732
