Micromachined accelerometer with a movable-gate-transistor sensing element

Autor: Howard Kaufman, Adolfo O. Gutierrez, E. W. Maby, Chris Cormeau, Daniel M. Edmans
Rok vydání: 1997
Předmět:
Zdroj: SPIE Proceedings.
ISSN: 0277-786X
DOI: 10.1117/12.284530
Popis: The development of a micromachined accelerometer with high frequency response in described. The accelerometer is based on a thin film layer of polysilicon suspended over a field- effect transistor (FET), forming a moveable-gate transistor. The field effect-transistor is designed for depletion-mode operation. Frequency response greater than 20,000 Hz is predicted with analytical models of the cantilever beam structure. Feedback control electrodes are included for closed-loop operation. The force-balance feedback control produces greater dynamic range and frequency response. The mechanical and electrical modeling of the micromachined structure with MEMCAD 3.0 are described. Results of the device modeling based on SUPREM-3 simulations are also included. This model includes the results of a short loop run carried out at MCNC to determine the interface charge in the transistor gate oxide. The anticipated effect of the oxide charge on the threshold voltage of the FET is included.
Databáze: OpenAIRE