Wafer construction for making single-crystal semiconductor device
US4549913A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 27, 1984 |
| Grant date | Oct 29, 1985 |
| Priority date | — |
| Expiry date | Jan 27, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/12528
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Seed crystals are made in a region of a polycrystalline layer on a substrate by melting the region and then cooling it so that it solidifies from one end to the other in a first direction and outwardly toward the edges in a second direction normal to the first direction. The desired cooling pattern is established by providing a thermal layer under the polycrystalline layer, which thermal layer is used to provide different rates of heat conduction therethrough in different parts of the thermal layer. A large, single-crystal device can be made by providing an operating layer of polycrystalline material in contact with the seed, melting the operating layer and recrystallizing it so that its solidification proceeds from the seed. The thermal layer can be used to ensure the desired direction of resolidification by providing different rates of heat conduction therethrough in different parts of the thermal layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.