Total immersion crystal growth
US4654110A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Nov 21, 1984 |
| Grant date | Mar 31, 1987 |
| Priority date | — |
| Expiry date | Nov 21, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B27/02
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Crystals of wide band gap materials are produced by positioning a holder (106, 274) receiving a seed crystal (106) at the interface (36, 270) between a body (26, 206) of molten wide band gap material and an overlying layer (28 or 288) of temperature-controlled, encapsulating liquid. The temperature of the layer decreases from the crystallization temperature of the crystal at the interface with the melt to a substantially lower temperature at which formation of crystal defects does not occur, suitably a temperature of 200.degree. C. to 600.degree. C. After initiation of crystal growth, the leading edge of the crystal (212) is pulled through the layer until the leading edge of the crystal enters the ambient gas headspace (30, 265) which may also be temperature controlled. The length of the column of liquid encapsulant may exceed the length of the crystal such that the leading edge and trailing edge of the crystal are both simultaneously with the column of the crystal. The crystal can be pulled vertically by means of a pulling-rotation assembly (20) or horizontally by means of a low-angle withdrawal mechanism (210). The temperature of the encapsulating layer is controlled by heating a…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.