Methods for fabricating memory devices
US6410412B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 15, 2000 |
| Grant date | Jun 25, 2002 |
| Priority date | — |
| Expiry date | Sep 15, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/927
- WIPO fieldMicro-structural and nano-technology
- WIPO sectorChemistry
Abstract
Methods for fabricating memory devices having a multi-dot floating gate ensuring a desirable crystallization of a semiconductor film without ruining the flatness of the surface of the polycrystallized silicon layer and a tunnel oxide film, allowing desirable semiconductor dots to be produced, and allowing production of the memory devices having a multi-dot floating gate with ease and at low costs even when a substrate is made of glass or plastic. Such a method for fabricating memory devices includes steps for forming on a substrate a semiconductor film and treating said semiconductor film by a first laser annealing so as to have a polycrystalline structure; forming on the semiconductor film a semiconductor dot forming film having a non-stoichiometric composition with an excessive content of a semiconductor element; and dispersing semiconductor dots within the semiconductor dot forming film by a second laser annealing thereby to produce semiconductor dots; in which a pulse energy density of the laser used for the first laser annealing is larger than a pulse energy density of the laser used for the second laser annealing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.