Method for preparing digital storage device by laser application
US4556524A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1982 |
| Grant date | Dec 3, 1985 |
| Priority date | — |
| Expiry date | Sep 30, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/24
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A digital storage device comprises a crystalline substrate such as silicon in which pockets of amorphous substrate material represent one of the binary logic states; the absence of amorphous material represents the other logic state. The amorphous material is formed by irradiation with a laser beam. Typically the radiation for silicon is at 347 nanometers, 2.5 nanosecond pulse length. The power density varies with crystalline orientation; for (001) silicon it is typically 0.3 J/cm.sup.2 and for (111) silicon it is 0.3 to 0.6 J/cm.sup.2. Erasure of the information is achieved by laser annealing the amorphous material back to its crystalline form.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.