Method of forming improved encapsulation layer
US4990464A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1988 |
| Grant date | Feb 5, 1991 |
| Priority date | — |
| Expiry date | Dec 30, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/154
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved technique for forming silicon-on insulator films for use in integrated circuits. The technique provides an improved encapsulation layer to enable in a reproducible way the zone melt recrystallization of such films. The encapsulation layer consists of a first layer of a doped SiO.sub.2 (silicate glass) on which a further layer of Si.sub.3 N.sub.4 is deposited. The doped SiO.sub.2 forms a fusible glassy material which is rendered semi-liquid and flows at the temperatures used in recrystallization. The softening of the encapsulation material accommodates volume expansion and eliminates the biaxial stresses in the layered structure. The Si.sub.3 N.sub.4 layer adds mechanical strength to the SiO.sub.2 layer and improves the wetting angle.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.