Growth of silicon single crystal having uniform impurity distribution along lengthwise or radial direction
US5700320A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Mar 22, 1996 |
| Grant date | Dec 23, 1997 |
| Priority date | — |
| Expiry date | Mar 22, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B15/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
When a B or P-doped Si single crystal is pulled up from a B or P-doped melt by the Czochralski method, an element such as Ga, Sb or In having the effect to reduce the heat expansion coefficient of said melt at a temperature near the melting point is added to said melt. The additive element stabilizes the temperature condition of crystal growth so as to control the generation of eddy flows just below the interface of crystal growth. When a Ga or Sb-doped Si single crystal is pulled up from a Ga or Sb-doped melt, an element such as B or P having the effect to increase the heat expansion coefficient of said melt at a temperature near the melting point is added. The agitation of the melt just below the interface of crystal growth is accelerated by the addition of B or P, so as to assure the growth of a Si single crystal from the melt having impurity distribution made uniform along the radial direction. Accordingly, a Si single crystal is formed having a uniform impurity distribution along its lengthwise or radial direction.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.