Process for making stoichiometric mixed metal oxide films
US5885648A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1997 |
| Grant date | Mar 23, 1999 |
| Priority date | — |
| Expiry date | May 27, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02205
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Oxide materials having a composition described by the formula SrBi.sub.2.00- Ta.sub.2.00-x Nb.sub.x O.sub.9, where x ranges from 0.00 to 2.00 and is controlled to within about 1%, are provided having improved high temperature performance. A batch of the desired composition is initially prepared by conventional processes to provide a nominal composition that may be close to the desired composition, but not the exact desired composition. A portion of the batch is processed to form a thin film, the stoichiometry of which is then analyzed. The batch composition is then modified by adding thereto a quantity of one or more of the constituents to bring the batch composition to the desired stoichiometry. Further improved high temperature performance is achieved with values of x within the range of about 0.10 to 1.9, and more preferably, about 0.4 to 0.7, and most preferably about 0.56. The thus-modified metal organic acid salt solutions provide ceramic thin films having improved electrical properties (particularly consistent properties from batch-to-batch, improved ferroelectric remnant polarization, and much improved high temperature performance) as compared to the thin films prepared fro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.