Title:
Micromachined capacitive silicon bulk acoustic wave gyroscopes

Simple item page
dc.contributor.advisor Ayazi, Farrokh
dc.contributor.advisor Degertekin, F. Levent
dc.contributor.author Johari, Houri en_US
dc.contributor.committeeMember Paul Kohl
dc.contributor.committeeMember Hesketh, Peter J.
dc.contributor.committeeMember Sitaraman, Suresh K.
dc.contributor.department Mechanical Engineering en_US
dc.date.accessioned 2010-01-29T19:37:32Z
dc.date.available 2010-01-29T19:37:32Z
dc.date.issued 2008-11-18 en_US
dc.description.abstract Micromachined gyroscopes are attractive replacements to conventional macro-mechanical and optical gyroscopes due to their small size, low power and low cost. The application domain of these devices is quickly expanding from automotive to aerospace and consumer electronics industries. As potential high volume consumer applications for micromachined gyroscopes continue to emerge, design and manufacturing techniques that improve their performance, shock survivability and reliability without driving up the cost and size become important. Today, state-of-the-art micromachined gyroscopes can achieve high performance with low frequency operation (3-30kHz) but at the cost of large form factor, large operating voltages and high vacuum packaging. At the same time, most consumer applications require gyroscopes with fast response time and high shock survivability, which are generally unavailable in low frequency gyroscopes. As a result, innovative designs and fabrication technologies that will offer more practical gyroscopes are desired. In this dissertation, capacitive bulk acoustic wave (BAW) silicon disk gyroscopes are introduced as a new class of micromachined gyroscope to investigate the operation of Coriolis-based vibratory gyroscopes at high frequency and further meet consumer electronics market demands. Capacitive BAW gyroscopes, operating in the frequency range of 1-10MHz are stationary devices with vibration amplitudes less than 20nm, resulting in high device bandwidth and high shock tolerance. They require low operating voltages, which simplifies the interface circuit design and implementation in standard CMOS technologies. They also demonstrate appropriate thermally stable performance in air, which eliminates the need both for vacuum packaging and for temperature control. A revised high aspect ratio poly- and single crystal silicon (HARPSS) process was utilized to implement these devices in thick SOI substrates with very small capacitive gap sizes (~200 nm). The prototype devices show ultra-high quality factors (Q>200,000) and large bandwidth of 15-30Hz. In addition, the design and implementation of BAW disk gyroscopes are optimized for self-matched mode operation. Operating a vibratory gyroscope in matched mode is a straightforward way to improve performance parameters but, is challenging to achieve without applying large voltages. In this work, self-matched mode operation was provided by enhanced design of the perforations of the disk structure. Furthermore, a multi-axis BAW gyroscope, an extension of the z-axis, is developed. This novel approach avoids the issues associated with integrating multiple proof masses, permitting a very small form factor. The multi-axis gyroscopes operate in out-of plane and in-plane modes to measure the rotation rate around the x- and z-axes. These gyroscopes were also optimized to achieve self-matched mode operation in their both modes. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/31656
dc.publisher Georgia Institute of Technology en_US
dc.subject Gyroscopes en_US
dc.subject MEMS en_US
dc.subject Bulk acostic wave en_US
dc.subject Disk en_US
dc.subject Capacitive en_US
dc.subject High aspect ratio en_US
dc.subject High frequency en_US
dc.subject SOI en_US
dc.subject HARPSS en_US
dc.subject.lcsh Gyroscopes
dc.subject.lcsh Micromachining
dc.subject.lcsh Acoustic surface wave devices
dc.title Micromachined capacitive silicon bulk acoustic wave gyroscopes en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Ayazi, Farrokh
local.contributor.advisor Degertekin, F. Levent
local.contributor.corporatename George W. Woodruff School of Mechanical Engineering
local.contributor.corporatename College of Engineering
relation.isAdvisorOfPublication 298d0abc-b13a-4bb8-a8c5-ba73301c2436
relation.isAdvisorOfPublication 9afd92fe-bb98-4c83-b8ac-fc596320991a
relation.isOrgUnitOfPublication c01ff908-c25f-439b-bf10-a074ed886bb7
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
johari_houri_200812_phd.pdf
Size:
13.87 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Theses and Dissertations