Microfabricated filter and shell constructed with a permeable me

Details Microfabricated filter and shell constructed with a permeable me Microfabricated filter and shell constructed with a permeable me

1996-06-24

1999-07-06

Fortuna, Ana

Liquid purification or separation

Casing divided by membrane into sections having inlet

Planar membrane

21050025, 21050026, 210483, 2103231, B01D 6300

Patent

active

059193646

ABSTRACT:
Microfabricated filters constructed with permeable polysilicon membranes and methods for fabricating such filters. The filters include a frame structure having a plurality of openings therethrough and a permeable polysilicon membrane disposed over the openings in the frame structure. The frame structure provides support for the permeable polysilicon membrane. The pores of the filter may be smaller than the resolution limit of photolithography. The width of the pores may be as small as about 0.01 .mu.m, while the length of the pores may be as small as about 0.05 .mu.m. The filters feature a relatively high throughput due to the extremely short pore length. The filters may be fabricated utilizing standard microfabrication processes. Also, microfabricated shells constructed with permeable membranes for encapsulating microfabricated devices such as microelectromechanical structures (MEMS) and methods for fabricating such shells. The shells include a frame structure having a plurality of openings therethrough, a permeable membrane disposed on the openings through the frame structure, an optional sealing structure disposed on the permeable membrane, and a cavity bounded by the frame structure. The frame structure provides support for the permeable membrane. The permeable membrane may be a thin film layer of polysilicon having a thickness of less than about 0.3 .mu.m. The shells and methods for fabricating the shells minimize the damage incurred by the encapsulated microfabricated device during the fabrication of the shell without restricting the width of the shell. The shells may be fabricated utilizing standard microfabrication processes.

REFERENCES:
patent: 3438504 (1969-04-01), Furman
patent: 4941893 (1990-07-01), Hsieh et al.
patent: 5466932 (1995-11-01), Young et al.
patent: 5589136 (1996-12-01), Northrup et al.
patent: 5644177 (1997-07-01), Guckel et al.
patent: 5659171 (1997-08-01), Young et al.
R. C. Anderson et al., "Formation, properties'and applications of porous silicon," Ph.D. Thesis'Dept. of Chemical Engineering, U.C. Berkeley, Apr. 1991.
R. C. Anderson et al. "Porous polycrystalline silicon: a new material for MEMS," Journal of Microelectromechanical Systems, vol.3, No. 1, Mar. 1994, pp. 10-18.
T. J. Brosnihan et al., "Surface micromachined angular accelrometer with force feedback," Proceedings of the ASME Dynamic Systems and Control Division, San Francisco, California, USA, 1995, pp. 941-947.
D. W. Burns, Micromechanics of intergrated sensors and the planar processed pressure transducers, Ph.D. Thesis, Department of Material Science, University of W'sconsin, Madison, W'sconsin, USA, 1988.
D. W. Burns et al., "A digital pressure sensor based on resonant microbeams," Proceedings of thc Solid-State Sensor and Actuator Workshop. Hilton Head, South Carolina, USA, Jun. 12-16, 1994, pp. 221-224.
Y. H. Cho et al., "Viscous energy dissipation in laterally oscillating planar microstructures: a theoretical and experimental study," Proceedings of the IEEE Micro Electro Mechanical Systems Workshop (MEM93). 1993, pp. 93-98.
M. Chonko et al., "The integrity of very thin silicon films deposited on SI02," The Physics and Chemistry of SiO.sub.2 and the Si-SiO.sub.2 Interface 2. edited by: C. R. Helms and B. E. Deal, Plenum Press, New York, USA, 1993, 357-362.
L. A. Field, Fluid-Actuated Micromachined Rotors and Gears, Ph.D. Thesis. EECS Department, University of California Berkley, Berkeley, California, USA, 1991.
H. Guckel and D. W. Burns, "Planar processed polysilicon sealed cavities for pressure transducer arrays," Pro-ceedings of the International Electron Devices Meeting. Dec. 9-12, 1984, pp. 223-225.
H. Guckel et al., "The application of fine-grained, tensile polysilicon to mechanically resonant transducers," Sensors and Actuators, vol. A21-23, 1990, pp. 346-351.
H. Guckel et al., "Polysilicon resonant microbeam technology for high performance sensor applications," Proceedings of the IEEE Solid-State Sensor and Actuator Workshop. Hilton Head, South Carolina, USA, Jun. 21-24, 1992, pp. 153-156.
H. Guckel, et al. "Construction and performance characteristics of polysilicon resonating beam force transducers", Elsevier Science Publishers. pp. 393-404.
H. Guckel et al., "Fabrication techniques for integrated sensor microstructures," IEDM, (1986) pp. 176-179.
H. Guckel et al., "Laser-recrystallized piezoresistive micro-diaphragm sensor," IEEE (1995) pp. 182-185.
H. Guckel, "Structure micromachined presure transducers," Elsevier Sequoia, Lausanne. (1991) pp. 133-146.
K. Ikeda et al., "Three dimensional micromachining of silicon resonant strain gauge," Digest of the 7th Sensor Symposium, Tokyo, Japan, 1988, pp. 193-196.
K. Ikeda et al., "Silicon pressure sensor with resonant strain gauge built into diaphragm," Digest of the 7th Sensor Symposium. Tokyo, Japan, 1988, pp. 55-58.
K. Ikeda, et al., "Silicon pressure sensor integrates resonant strain gauge on diaphram," Sensors and Actuators. (1990), pp. 146-150.
K. Ikeda, et al., "Three-dimensional micromachining of silicon pressure sensor integrating resonant strain gauge on diaphram," Sensors and Actuators. (1990) pp. 1007-1010.
P. T. Jones, A Micro-Electro-Mechanical Systems (MEMS) Devices to Measure the Fracture Strain of Polycrystalline Silicon, M. S. Thesis. ME Department, University of California at Berkeley, Berkeley, California, USA, 1995.
M. W. Judy and R. T Howe, "Polysilicon hollow beam lateral resonators," Proceedings of the IEEE Micro Electro Mechanical Systems Workshop. Fort Lauderdale, Florida, USA, Feb. 1-10, 1993, pp. 265-271.
M. W. Judy, "Micromechanisms using sidewall beams," Ph.D. Thesis, EECS Dept., U.C. Berkeley, May 1994.
K S. Lebowitz et al., "Permeable polysilicon etch-access windows for microshell fabrication." In: 8th International Conference on Solid-State Sensors and Actuators and Eurosensors IX. Digest of Technical Papers (IEEE Cat. no.95TH8173). (8th International Conference on Solid-State Sensors and Actuators and Eurosensors IX. Digest of Technical Papers (IEEE Cat. No.95TH8173) Proceedings of the International Solid-State Sensors and Actuators Conference -Transducers '95, Stockholm, Sweden, Jun. 25-29, 1995). Sweden: Found. Sensors & Actuator Techol. 1995. pp. 224-227 vol. 1. vacuum-encapsulated polysilicon resonators. Part I: design and fabrication," Sensors and Actuators. vol. A45, 1994, kpp. 57-66.
L. Lin et al., "Silicon processed microneedles," 7th International Conference on Solid-State Sensors and Actuators (Transducers 93). Yokohama, Japan, Jun. 7-10, 1993, pp. 237-240.
L. Lin et al., "Vacuum-encapsulated lateral microresonators," 7th International Conference on Solid-State Sensors and Actuators (Transducers 93). Yokohama, Japan, Jun. 7-10, 1993, pp. 270-273.
L. Lin, Selective Encapsulation of MEMS: Micro Channels, Needles, Resonators and Electromechanical Filters, Ph D. Thesis. ME Department, University of California Berkeley, Berkeley, California, US.about. Dec. 1993.
C. Liu et al., "Studies on the sealing of surface micromachined vacitires using chemical vapor deposition materials" Electrical Engineering. Jun. 1994, pp. 103-106.
C. H. Mastrangelo et al. "Vacuum-sealed silicon micromachined incandescent light source," IEEE International Electron Devices Meeting. San Francisco, California, USA, Dec., 1989, pp. 503-506.
D.J. Monk et al., "Hydrofluoric acid etching of silicon dioxide sacrificial layers. I. Experimental observations," Journal of the Electrochemical Society. vol. 141, 1994, pp. 264-274.
D. J. Monk et al., "Stress-corrosion cracking and blistering of thin polysilicon films in hydrofluoric acid" Materials Research Society Symposium Proceedings. vol. 308, San Francisco, California, USA, May 1993, pp. 641-646.
G. T. Mulhern et al., "Supercritical carbon dioxide drying of microstructures," 7th International Conference on Solid-State Sensors and Actuators (Transducers 93). Yokohama, Japan, Jun. 7-10, 1993, pp. 296-299.
C. T.-C. Nguyen et al., "Design and performance of CMOS micromechanical resonator oscillators," Proceedings of the 1994 IEEE International Frequency Control Symposium. Boston

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