Growth of silicon crystal from melt having extraordinary eddy flows on its surface
US5704974A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 22, 1996 |
| Grant date | Jan 6, 1998 |
| Priority date | — |
| Expiry date | Mar 22, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B15/30
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
When a Si single crystal 8 is pulled up from a melt 6 received in a crucible 2, the state of eddy flows generated in the melt 6 is judged from the temperature distribution of the melt at the surface. According to the result of judgement, the gas, i.e. N.sub.2, Xe or Kr, which causes extraoridnary deviation in the density of a melt 6 is added to an atmospheric gas, so as to keep the eddy flows under unstabilized condition. The effect of said gas is typical in the case of crystal growth from the melt to which a dopant such as Ca, Sb, Al, As or In having the effect to suppress the extraordinary deviation in the density is added. Since the single crystal is pulled up from the melt held in the temperature-controlled condition at the surface, impurity distribution and oxygen distribution are made uniform along the direction of crystal growth. A single crystal obtained in this way has highly-stabilized quality.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.