Method of forming electrical connections to high dielectric constant materials
US5348894A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1993 |
| Grant date | Sep 20, 1994 |
| Priority date | — |
| Expiry date | Jan 27, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49128
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A preferred embodiment of this invention comprises an oxidizable layer (e.g. tantalum 48), an oxygen gettering layer (e.g. platinum/tantalum mixture 34) overlaying the oxidizable layer, a noble metal layer (e.g. platinum 36) overlaying the oxygen gettering layer, and a high-dielectric-constant material layer (e.g. barium strontium titanate 38) overlaying the noble metal layer. The novel structures presented provide electrical connection to high-dielectric-constant materials without the disadvantages of current structures. The oxygen gettering layer controls oxygen diffusion, minimizing the formation of a resistive layer either in the lower electrode or at the lower electrode/substrate interface. The oxygen gettering layer acts as a gettering site for oxygen, where the oxygen oxidizes the reactive metal portion of the layer, leaving the noble metal portion of the layer intact. While the oxides/suboxides (e.g. tantalum pentoxide 40) that are formed are resistive, they are dispersed within the noble metal matrix, leaving a conductive path from the top of the layer to the bottom. This invention provides a stable and electrically conductive electrode for high-dielectric-constant materia…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.