Semiconductor nitride pressure microsensor and method of making and using the same
US6647796B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 7, 2001 |
| Grant date | Nov 18, 2003 |
| Priority date | — |
| Expiry date | Aug 7, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L9/0055
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An integrated microsensor includes a bowed micromachined membrane coupled to a substrate to define a microcavity therebetween. An integrated strain sensor is coupled to the micromachined membrane to generate a signal responsive to (deformation of the membrane and hence responsive to the pressure of the fluid in the microcavity. A frame is coupled to the peripheral edge of the membrane to assist in enlarging the microcavity. The membrane is composed of a nitride of B, Al, Ga, In, Tl or combinations thereof, or more particularly of p-type GaN where the frame is comprised of n-type GaN. The membrane and frame are fabricated using a photoelectrochemical etching technique. The fabrication of the integrated strain sensor creates stresses across the membrane. The strain sensor comprises an integrated circuit strain-FET. The strain-FET comprises an AlGaN/GaN heterostructure having an AlGaN/GaN interface where deformation of the membrane is coupled as strain to the AlGaN/GaN piezoelectric interface.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.