Integrated tunable surface acoustic wave technology and sensors provided thereby
US6621192B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 13, 2001 |
| Grant date | Sep 16, 2003 |
| Priority date | — |
| Expiry date | Jul 13, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/33
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention provides a ZnO based tunable surface acoustic wave (SAW), preferably monolithically integrated tunable SAW (MITSAW) device. The MITSAW comprises a ZnO/Mgx Zn1−xO quantum well structure and piezoelectric ZnO thin film epitaxially grown on R-plane sapphire ((01{overscore (1)}2)Al2O3) substrate using MOCVD. R-plane sapphire provides in-plane anisotropy in the ZnO layer as the c-axis of ZnO lies in the growth plane. A two-dimensional electron gas (2DEG) is placed in the delay path of the SAW device and interacts with the lateral electric field resulting in ohmic loss which attenuates and slows the surface acoustic wave. This mechanism is used to tune the acoustic velocity. The high coupling coefficients offered by the ZnO/R-(Al2O3) system allows large velocity tuning. ZnO based MITSAW is used for chemical and biochemical sensors, offers excellent manufacturability, high yield and low cost. Such SAW sensors have a “resettable” sensing mechanism. The multiple acoustic wave modes are used for improved sensitivity and simultaneously use UV absorption measurement and SAW sensing mechanisms.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.