Semiconductor memory device having shallow trench isolation structure
US6057580A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 7, 1998 |
| Grant date | May 2, 2000 |
| Priority date | — |
| Expiry date | Jul 7, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B41/30
Abstract
In a nonvolatile semiconductor memory device, those sides of the gate insulating film and the floating gate electrode which oppose an inner side of a trench are oxidized to form an oxide film. The gate insulating film, the floating gate electrode, and that portion of semiconductor substrate which is near the gate insulating film oppose an insulator made of a first material buried in the trench via another insulator made of a second material difference from the first material buried in the trench. The first material has a low diffusability of impurities, and is, for example, silicon nitride, which effectively suppresses diffusion of impurities from the second material into the gate insulating film.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.