A new design and a fabrication approach to realize a high performance three axes capacitive MEMS accelerometer

2016-06-15
Aydemir, Akin
Terzioglu, Yunus
Akın, Tayfun
This paper presents a new fabrication approach and design for a three axis capacitive MEMS accelerometer that is capable of measuring externally applied accelerations in three orthogonal axes. Individual lateral and vertical axis accelerometers are fabricated in the same die on an SOI wafer which is anodically bonded to a glass substrate. Handle layer of the SOI wafer is used as the top electrode for the vertical axis accelerometer. This accelerometer has a 2 mm(2) perforated electrode area anchored to the glass substrate by four beams. The lateral axis accelerometers on the other hand, have comb finger structures with a 2.7 x 4.2 mm device size and anchored to the glass substrate by six folded beams. Rest capacitance of the vertical axis accelerometer is designed to be 8.8 pF, and it is 10.2 pF for the lateral axis accelerometers. The system level performance results are obtained using analog readout circuitry integrated to each axis separately. The x- and y-axis accelerometers show a noise floor and bias instability equal or better than 13.9 mu g/root Hz and 17 mu g, respectively, while the z-axis accelerometer shows 17.8 mu g/root Hz noise floor and 36 mu g bias instability values.
SENSORS AND ACTUATORS A-PHYSICAL

Suggestions

Process Development for the Fabrication of a Three Axes Capacitive MEMS Accelerometer
Aydemir, Akin; Akın, Tayfun (2015-09-09)
This paper presents a new approach for the fabrication of a three-axis capacitive MEMS accelerometer that is capable of differentially sensing the acceleration in all three orthogonal axes. For the first time in literature, differential sensing for the out of plane direction is achieved by defining a movable sensing electrode on the structural layer of the SOI wafer that is sandwiched between two stationary electrodes defined on the glass substrate and the handle layer of the SOI wafer enabling the differen...
Fabrication of a Three-Axis Capacitive MEMS Accelerometer on a Single Substrate
Aydemir, Akin; Akın, Tayfun (2015-11-04)
This paper presents a new fabrication approach and a design for the fabrication of a three-axis capacitive MEMS accelerometer where differential sensing is enabled for all sense directions. In this approach, individual lateral and vertical axis accelerometers are fabricated in the same die on an SOI wafer which is eutectically bonded to a glass substrate. Differential sensing for the vertical axis accelerometer is realized by defining the proof mass of the accelerometer on the structural layer of the SOI wa...
A single mass two-axis capacitive MEMS accelerometer with force rebalance
Köse, Talha; Terzioʇlu, Yunus; Azgın, Kıvanç; Akın, Tayfun (2015-03-26)
This paper presents a single mass 2-axis MEMS capacitive accelerometer with a unique force rebalance method achieved with the readout circuit developed for the simultaneous 2-axis acceleration sensing. Using a single mass structure with extra fingers for reading multiple axes allows better sensor performances when compared to multi-axis accelerometers with individual proof masses occupying the same die area. Test results show 274 mV/g scale factor for x-axis, and 280 mV/g scale factor for y-axis, while the ...
Precision readout circuits for capacitive microaccelerometers
Yazdi, N; Külah, Haluk; Najafi, K (2004-01-01)
This paper presents a review of capacitive readout front-end circuits for high-precision accelerometers. The primary design parameters and the trade-offs affecting the resolution are presented. The discussions apply to all capacitive microsensor interfaces. Also a high-sensitivity capacitive accelerometer interface circuit for hybrid-integration with a surface/bulk micromachined micro-g accelerometer is described [7, 10]. The first generation of the circuit resolves 75aF of capacitance on similar to 120pF p...
SELF-PACKAGED THREE AXIS CAPACITIVE MEMS ACCELEROMETER
Aydemir, Akin; Akın, Tayfun (2020-01-01)
This paper presents the design, fabrication, and characterization of a self-packaged three axis capacitive MEMS accelerometer fabricated by using only four masks that is capable of differentially sensing the externally applied accelerations in three orthogonal axes. Individual lateral and vertical axis accelerometers are fabricated in the same die on a SOT wafer, which is eutectically bonded to a silicon substrate. Handle layer of the SOT wafer is both used as the top electrode for the vertical axis acceler...
Citation Formats
A. Aydemir, Y. Terzioglu, and T. Akın, “A new design and a fabrication approach to realize a high performance three axes capacitive MEMS accelerometer,” SENSORS AND ACTUATORS A-PHYSICAL, pp. 324–333, 2016, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/33102.