Adhesion layer for platinum based sensors
US4952904A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1988 |
| Grant date | Aug 28, 1990 |
| Priority date | — |
| Expiry date | Dec 23, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01C7/006
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The marginal adhesion of platinum to silicon nitride is a serious issue in the fabrication of microbridge mass air flow sensors. High temperature stabilization anneals (500.degree.-1000.degree. C.) are necessary to develop the properties and stability necessary for effective device operation. However, the annealing process results in a significant reduction in the already poor platinum/silicon nitride adhesion. Annealing at relatively high temperatures leads to the development of numerous structural defects and the production of non-uniform and variable sensor resistance values. The use of a thin metal oxide adhesion Layvr, approximately 20 To 100 angstromw in thickness is very effective in maintaining platinum adhesion to silicon nitride, and through the high temperature anneal sequence.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.