Method for laser melting of silicon
US4468279A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 16, 1982 |
| Grant date | Aug 28, 1984 |
| Priority date | — |
| Expiry date | Aug 16, 2002 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S117/904
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A method for laser melting of silicon for the production of boules pulled from a pool of liquid ultraclean or ultrapure silicon wherein the boules are used for producing silicon wafers suitable for use in the electronics field. A laser beam, preferably P polarized, is directed at an angle of about 88 degrees to the normal to the surface of silicon disposed in conventional melting apparatus. A suitable mirror is preferably provided to capture and reflect that portion of the laser beam reflected from the surface of the pool. Use of the present invention permits continuous operation by adding solid silicon and melting it at the point of impingement of the laser beam with up to about 96% absorption of laser energy at this point, thereby permitting the provision of heat in a very controlled manner in a continuous ultraclean silicon crystal growth process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.