Tailoring piezoelectric properties using MgxZn1-xO/ZnO material and MgxZn1-xO/ZnO structures
US6716479B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 2002 |
| Grant date | Apr 6, 2004 |
| Priority date | — |
| Expiry date | Oct 7, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10N30/853
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention provides magnesium zinc oxide (MgxZn1-xO) as a new piezoelectric material, which is formed by alloying ZnO and MgO. MgxZn1-xO allows for flexibility in thin film SAW and BAW device design, as its piezoelectric properties can be tailored by controlling the Mg content, as well as by using MgxZn1-xO/ZnO multilayer structures. To experimentally prove it, the MgxZn1-xO (x≦0.35) thin films are grown on r-plane sapphire substrates at a temperature in the range of 400° C.-500° C. by metalorganic chemical vapor deposition. MgxZn1-xO films with Mg mole percent up to 0.35 have epitaxial quality and wurtzite crystal structure. The SAW properties, including velocity dispersion and piezoelectric coupling, are characterized and concluded that the acoustic velocity increases, whereas the piezoelectric coupling decreases with increasing Mg mole percent in piezoelectric MgxZn1-xO films.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.