Polysilicon resonating beam transducers and method of producing

Details Polysilicon resonating beam transducers and method of producing Polysilicon resonating beam transducers and method of producing

1992-01-03

1993-02-23

Hearn, Brian E.

Fishing, trapping, and vermin destroying

437213, 437215, 7386259, H01L 2160

Patent

active

051889838

ABSTRACT:
Force transducers are formed of a beam of polysilicon which is mounted at its ends to a silicon substrate and is encapsulated within a polysilicon shell which defines, with the substrate, a cavity around the resonating beam. The cavity is sealed off from the atmosphere and evacuated to maximize the Q of the resonating beam. The beam is produced by deposition of polysilicon in such a way that, combined with subsequent annealing steps, the beam is in zero or low tensile strain. Resonant excitation of the beam may be accomplished in various ways, including capacitive excitation, and the vibratory motion of the beam may be detected utilizing an implanted resistor which is piezoresistive. Formation of the beam is carried out by depositing the beam on a sacrificial layer and surrounding it in a second sacrificial layer before the encapsulating polysilicon shell is formed. The sacrificial layers are etched out with liquid etchant which passes through channels in the periphery of the shell. Following etching, the interior of the cavity surrounding the beam is maintained in a wash liquid so that the beam is not deflected toward any of the adjacent surfaces, and the wash liquid is removed by freezing and su

REFERENCES:
patent: 4567451 (1986-01-01), Greenwood
patent: 4744863 (1988-05-01), Guckel et al.
patent: 4772786 (1988-09-01), Guckel et al.
patent: 4805456 (1989-02-01), Howe et al.
patent: 4841775 (1989-06-01), Ikeda et al.
patent: 4853669 (1989-08-01), Guckel et al.
patent: 4897360 (1990-01-01), Guckel et al.
patent: 4901570 (1990-02-01), Chang et al.
patent: 5013693 (1991-05-01), Guckel et al.
K. E. B. Thornton, et al., "Optically Excited Micromechanical Resonator Pressure Sensor", Optical Fiber Sensors 1988 Technical Digest Series, vol. 2, Part 2, New Orleans, La., Jan. 1988, pp. 433-436.
K. Ikeda, et al., "Silicon Pressure Sensor with Resonant Strain Gages Built into Diaphragm", Technical Digest of the 7th Sensor Symposium, Shigaki Kaikan, Tokyo Japan, 30-31 May 1988, pp. 55-58.
K. Ikeda, et al., "Three Dimensional Micromachining of Silicon Resonant Stain Gage", Technical Digest of the 7th Sensor Symposium, Shigaki Kaikan, Japan, 30-31 May 1988, pp. 193-196.
K. Ikeda, et al., "Study of Nonlinear Vibration of Si Resonant Beam Strain Gage", Technical Digest of the 8th Sensor Symposium, 1989, Tokyo, Japan, pp. 12-24.
H. Guckel, J. Sniegowski, T. Christenson, "Advances in Processing Techniques for Silicon Micromechanical Devices with Smooth Surfaces", Proceedings IEEE Micro Electro Mechanical Systems, Salt Lake City, Utah, Feb. 20-22, 1989, pp. 71-75.
H. Guckel, J. Sniegowshi, T. Christenson, F. Raissi, "The Application of Fine Grain, Tensile Polysilicon to Mechanically Resonant Transducers", copy of a paper relating to an oral presentation made by T. Christenson at Transducers '89, the 5th International Conference on Solid State Sensors and Actuators & Euro-sensors III, Jun. 25-30, 1989, in Montreux, Switzerland.
H. Guckel, J. Sniegowski, T. Christenson, "Construction and Performance Characteristics of Polysilicon Resonating Beam Force Transducers", a paper representing the content of a talk presented by H. Guckel at the Toyota Conference, Oct. 22-25, 1989 in Japan.
H. Guckel, J. Sniegowski, T. Christenson, S. Mohney, T. Kelly, "Fabrication of Micromechanical Devices from Polysilicon Films with Smooth Surfaces", Sensors and Actuators, vol. 20, Nov. 15, 1989, pp. 117-122.

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