Title :
Area minimization of a three-axis separate mass capacitive accelerometer using the ThELMA process
Author :
Briffa, Ansel ; Gatt, E. ; Micallef, J. ; Grech, I. ; Casha, O. ; Darmanin, Jean Marie
Author_Institution :
Dept. of Microelectron. & Nanoelectron., Univ. of Malta, Msida, Malta
Abstract :
This paper presents a comparison between two designs of capacitive accelerometers implemented using the Thick Epitaxial Layer for Micro-actuators and Accelerometers (ThELMA) process. The design methodology aims to reduce the total device area whilst using a separate mass approach for the three different axes. The designs use a folded spring topology and serpentine spring topology for the in-plane sensors and torsional springs for the out-of-plane (Z-axis) sensor. The sensors have a resonant frequency of about 1.7 kHz, a maximum acceleration of 13g, a sensitivity of around 8 fF/g and a mechanical cross-axis sensitivity of less than 1%. A reduction of 23% in device area was achieved between these two designs, without a reduction in performance.
Keywords :
accelerometers; capacitive sensors; epitaxial layers; microactuators; ThELMA process; area minimization; folded spring topology; in-plane sensors; out-of-plane sensor; serpentine spring topology; thick epitaxial layer for microactuators and accelerometers process; three-axis separate mass capacitive accelerometer; torsional springs; Accelerometers; Electrodes; Fingers; Resonant frequency; Sensitivity; Sensors; Springs; Accelerometer; Area Minimization; Capacitive sensing; MEMS; Separate Mass;
Conference_Titel :
EUROCON, 2013 IEEE
Conference_Location :
Zagreb
Print_ISBN :
978-1-4673-2230-0
DOI :
10.1109/EUROCON.2013.6625269