A fully-differential bulk-micromachined mems accelerometer with interdigitated fingers

Download

index.pdf

Date

2012

Author

Aydın, Osman

Metadata

Show full item record

Item Usage Stats

270
views

177
downloads

Accelerometer sensors fabricated with micromachining technologies started to take place of yesterday’s bulky sensors in many application areas. The application areas include a wide range from consumer electronics and health systems to military and aerospace applications. Therefore, the performance requirements extend form 1 μg’s to 100 thousand g’s. However, high performance strategic grade MEMS accelerometer sensors still do not exist in the literature. Smart designs utilizing the MEMS technology is necessary in order to acquire high performance specifications. This thesis reports a high performance accelerometer with a new process by making the use of bulk micromachining technology. The new process includes the utilization of Silicon-on-Insulator (SOI) wafer and its buried oxide (BOX) layer. The BOX layer helps to realize interdigitated finger structures, which commonly find place in surface micromachined CMOS-MEMS capacitive accelerometers. The multi-metal layered CMOS-MEMS devices inherently incorporate interdigitated finger structures. Interdigitated finger structures are highly sensitive to acceleration in comparison with comb-finger structures, which generally find usage in bulk-micromachined devices, due to absence of anti-gap. The designed sensors based on this fabrication process is sought to form a fully-differential signal interfaced sensor with incorporation of the advantages of high sensitive interdigitated finger electrodes and high aspect ratio SOI wafer’s bulk single crystal silicon device. Under the light of the envisaged process, sensor designs were made, and verified using a computing environment, MATLAB, and a finite element analysis simulator, CoventorWARE. The verified two designs were fabricated, and all the tests, except the centrifuge test, were made at METU-MEMS Research Center. Among the fabricated sensors, the one designed for the high performance achieves a capacitance sensitivity of 178 fF with a rest capacitance of 8.1 pF by employing interdigitated finger electrodes, while its comb-finger implementation can only achieve a capacitance sensitivity of 75 fF with a rest capacitance of 10 pF.

Subject Keywords

Electric Apparatus and Materials., Electric Circuits., Electric Networks.

URI

http://etd.lib.metu.edu.tr/upload/12614147/index.pdf
https://hdl.handle.net/11511/21458

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

A Compact Angular Rate Sensor System Using a Fully Decoupled Silicon-on-Glass MEMS Gyroscope Alper, Said Emre; Temiz, Yuksel; Akın, Tayfun (Institute of Electrical and Electronics Engineers (IEEE), 2008-12-01) This paper presents the development of a compact single-axis angular rate sensor system employing a 100-mu m-thick single-crystal silicon microelectromechanical systems gyroscope with an improved decoupling arrangement between the drive and sense modes. The improved decoupling arrangement of the gyroscope enhances the robustness of sensing frame against drive-mode oscillations and therefore minimizes mechanical crosstalk between the drive and sense modes, yielding a small bias instability. The gyroscope cor...
A low cost uncooled infrared microbolometer focal plane array using the CMOS n-well layer Tezcan, DS; Eminoglu, S; Akar, OS; Akın, Tayfun (2001-01-25) This paper reports a low-cost, 256-pixel uncooled infrared microbolometer focal plane array (FPA) implemented using a 0.8 mum CMOS process where the n-well layer is used as the active microbolometer material. The suspended n-well structure is obtained by simple front-end bulk etching of the fabricated CMOS dies, while the n-well region is protected from etching by electrochemical etch-stop technique within a TMAH solution. Electrical connections to the suspended n-well are obtained with polysilicon intercon...
Permanent magnet design and image reconstruction algorithm for magnetic resonance imaging in inhomogeneous magnetic fields Yiğitler, Hüseyin; Eyüboğlu, Behçet Murat; Department of Electrical and Electronics Engineering (2006) Recently, the use of permanent magnets as magnetic field sources in biomedical applications has become widespread. However, usage of permanent magnets in magnetic resonance imaging (MRI) is limited due to their inhomogeneous magnetic field distributions. In this thesis, shape and geometry optimization of a magnet is performed. Moreover, placement of more than one magnet is optimized to obtain desired magnetic field distribution in specific region of space. However, obtained magnetic field distribution can n...
A bulk-micromachined fully-differential MEMS accelerometer with interdigitated fingers Aydin, Osman; Akın, Tayfun (2012-10-31) This paper proposes a novel bulk-micromachined MEMS accelerometer employing interdigitated sense fingers that provide a fully-differential (FD) signal interface, where the accelerometer can be fabricated by a modified Silicon-on-Glass (M-SOG) process utilizing a <;111>; Silicon-on-Insulator (SOI) wafer. The accelerometer combines the feasibility of fabricating large mass and high aspect ratio structures using bulk-micromachining together with the high sensitive interdigitated sense finger triplets that are ...
An 80x80 Microbolometer Type Thermal Imaging Sensor using the LWIR-Band CMOS Infrared (CIR) Technology Tankut, Firat; Cologlu, Mustafa H.; Askar, Hidir; Ozturk, Hande; Dumanli, Hilal K.; Oruc, Feyza; Tilkioglu, Bilge; Ugur, Beril; Akar, Orhan Sevket; Tepegoz, Murat; Akın, Tayfun (2017-04-13) This paper introduces an 80x80 microbolometer array with a 35 mu m pixel pitch operating in the 8-12 aem wavelength range, where the detector is fabricated with the LWIR-band CMOS infrared technology, shortly named as CIR, which is a novel microbolometer implementation technique developed to reduce the detector cost in order to enable the use of microbolometer type sensors in high volume markets, such as the consumer market and IoT. Unlike the widely used conventional surface micromachined microbolometer ap...

Citation Formats

O. Aydın, “A fully-differential bulk-micromachined mems accelerometer with interdigitated fingers,” M.S. - Master of Science, Middle East Technical University, 2012.