Excimer laser dopant activation of backside illuminated CCD's
US5688715A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1995 |
| Grant date | Nov 18, 1997 |
| Priority date | — |
| Expiry date | Aug 14, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/09
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method uses an excimer laser to activate previously implanted dopant species in the backside of a backside-illuminated CCD or to incorporate dopant ions from a gaseous ambient into the backside of a backside-illuminated CCD and simultaneously activate. The controlled ion implantation of the backside and subsequent thin layer heating by the short wavelength pulsed excimer laser energy activates the dopant and provides for an improved dark current response and improved spectral response. The energy of the pulsed excimer laser is applied uniformly across a backside-illuminated CCD in a very thin layer of the semiconductor substrate (usually silicon) material that requires annealing to uniformly activate the dopant. The very thin layer of the material can be heated to exceedingly high temperatures on a nanosecond time scale while the bulk of the delicate CCD substrate remains at low temperature. Repair of semiconductor dies by effecting a uniform annealing enables salvage and utilization of otherwise discardable components by bringing their dark current response to within an acceptable range.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.