Fast Dry Fabrication Process with Ultra-Thin Atomic Layer Deposited Mask for Released MEMS-Devices with High Electromechanical Coupling

Author

Koskenvuori, M. ; Chekurov, N. ; Airaksinen, V.M. ; Tittonen, I.

Author_Institution

Helsinki Univ. of Technol., Espoo

fYear

2007

fDate

10-14 June 2007

Firstpage

501

Lastpage

504

Abstract

A fast, dry micro fabrication process combining atomic layer deposition, electron beam lithography and cryogenic deep reactive ion etching (DRIE) is presented. The process utilizes atomic layer deposited ultra-thin (t_ax < 5 nm) aluminum oxide (Al₂O₃) films as hard mask for the DRIE that is used for both vertical cavity and dry release etching. The use of ultra-thin films can be explained by the extremely high selectivity (1:70 000) between Al₂O₃ and silicon. The process rules and limitations are carefully analyzed and in order to test the process, multiresonant tuning fork resonators are fabricated.

Keywords

alumina; atomic layer deposition; cryogenics; electromagnetic coupling; electron beam lithography; elemental semiconductors; masks; microcavities; micromechanical resonators; silicon; sputter etching; DRIE; MEMS devices; Si-Al₂O₃; aluminum oxide films; atomic layer deposition; cryogenic deep reactive ion etching; dry microfabrication process; dry release etching; electromechanical coupling; electron beam lithography; multiresonant tuning fork resonators; ultra-thin atomic layer deposited mask; vertical cavity; Aluminum oxide; Atomic layer deposition; Cryogenics; Dry etching; Electron beams; Fabrication; Lithography; Semiconductor films; Silicon; Testing; Atomic layer deposition; cryogenic etching; fabrication; micromechanics;

fLanguage

English

Publisher

ieee

Conference_Titel

Solid-State Sensors, Actuators and Microsystems Conference, 2007. TRANSDUCERS 2007. International

Conference_Location

Lyon

Print_ISBN

1-4244-0842-3

Electronic_ISBN

1-4244-0842-3

Type

conf

DOI

10.1109/SENSOR.2007.4300177

Filename

4300177