Growth of silicon single crystal
US5683504A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 22, 1996 |
| Grant date | Nov 4, 1997 |
| Priority date | — |
| Expiry date | Mar 22, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S117/901
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
When a single crystal is pulled up from a melt, the difference .DELTA.T between temperatures at the bottom of a crucible and at the interface of crystal growth is controlled so as to hold the Rayleigh constant defined by the formula of: EQU R a=g.multidot..beta..multidot..DELTA.T.multidot.L/.kappa..multidot..nu. within the range of 5.times.10.sup.5 -4.times.10.sup.7, wherein g represents the acceleration of gravity, .beta. the volumetric expansion coefficient of the melt, L the depth of the melt, .kappa. thermal diffusivity and .nu. the kinematic viscocity. Since the convection mode of the melt at the interface of crystal growth is constantly held in the region of soft turbulence, a single crystal is grown under the stabilized temperature condition without the transfer of the impurity distribution in the melt into the growing single crystal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.