Apparatus and method for laser radiation
US5900980A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 6, 1997 |
| Grant date | May 4, 1999 |
| Priority date | — |
| Expiry date | Feb 6, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D86/0251
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is provided an improvement on homogeneity of annealing performed utilizing radiation of a laser beam on a silicon film having a large area. In a configuration wherein a linear laser beam is applied to a surface to be irradiated, optimization is carried out on the width and number of cylindrical lenses forming homogenizers 103 and 104 for controlling the distribution of radiation energy density in the longitudinal direction of the linear beam. For example, the width of the cylindrical lenses forming the homogenizers 103 and 104 is set in the range from 0.1 mm to 5 mm, and the number of the lenses is chosen such that one lens is provided for every 5 mm-15 mm along the length of the linear laser beam in the longitudinal direction thereof. This makes it possible to improve homogeneity of the radiation energy density of the linear laser in the longitudinal direction thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.