Method of spatially selective laser-assisted doping of a semiconductor
US7799666B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2009 |
| Grant date | Sep 21, 2010 |
| Priority date | — |
| Expiry date | Jul 27, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/2254
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method utilizing spatially selective laser doping for irradiating predetermined portions of a substrate of a semiconductor material is disclosed. Dopants are deposited onto the surface of a substrate. A pulsed, visible beam is directed to and preferentially absorbed by the substrate only in those regions requiring doping. Spatial modes of the incoherent beam are overlapped and averaged, providing uniform irradiation requiring fewer laser shots. The beam is then focused to the predetermined locations of the substrate for implantation or activation of the dopants. The method provides for scanning and focusing of the beam across the substrate surface, and irradiation of multiple locations using a plurality of beams. The spatial selectivity, combined with visible laser wavelengths, provides greater efficiency in doping only desired substrate regions, while reducing the amount of irradiation required. Savings in cost and manufacturing throughput can be achieved, particularly with respect to doping poly-crystalline silicon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.