Technology for local oxidation of silicon
US5374583A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 24, 1994 |
| Grant date | Dec 20, 1994 |
| Priority date | — |
| Expiry date | May 24, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/05
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A new method of local oxidation by means of forming a plurality of silicon trenches is described. Portions of the insulating layer over the surface of a silicon substrate not covered by a mask pattern are etched through exposing the portion of the silicon substrate that will form the device isolation region. A first trench is etched into the exposed portion of the substrate. A layer of silicon nitride is deposited over the insulating layer and within the trench. A layer of an aluminum-silicon alloy is deposited overlying the silicon nitride layer. The aluminum-silicon layer is etched away whereby silicon nodules are formed on the surface of the silicon nitride layer. The nodules are oxidized to form silicon dioxide nodules. Using the silicon dioxide nodules as a mask, the silicon nitride layer is etched through to the insulating layer where it exists and to the silicon substrate surface where it is exposed and a set of narrow trenches is etched into the exposed portions of the substrate. The silicon substrate within the set of trenches is oxidized wherein the silicon is transformed to silicon dioxide and the silicon dioxide expands to fill the set of trenches. The silicon nitride l…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.