Piezoelectric micromachined ultrasonic transducer with air-backed cavities
US7449821B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 2, 2005 |
| Grant date | Nov 11, 2008 |
| Priority date | — |
| Expiry date | Sep 30, 2025 |
Classification
- Technology area (CPC A)Human Necessities
- CPC primaryA61B8/4483
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A piezoelectric micromachined ultrasonic transducer comprising a substrate and a first dielectric film formed on the substrate. An opening having a sidewall is formed through the substrate and first dielectric film. A bottom electrode is formed on the first dielectric film spanning the opening. A piezoelectric element is formed on the bottom electrode. A second dielectric film surrounds the piezoelectric element. A conformal insulating film is formed on the sidewall of the opening. A conformal conductive film is formed in contact with the bottom electrode and on the sidewall of the opening, wherein an open cavity is maintained in the opening. A top electrode is formed in contact with the piezoelectric element.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.