Nonvolatile semiconductor memory device and method of manufacturing the same
US7989880B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 10, 2009 |
| Grant date | Aug 2, 2011 |
| Priority date | — |
| Expiry date | Nov 10, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A nonvolatile semiconductor memory device comprises a memory string, and a wiring. The memory string comprises a semiconductor layer, a charge storage layer, and a plurality of first conductive layers. The plurality of first conductive layers comprises a stepped portion formed in a stepped shape such that positions of ends of the plurality of first conductive layers differ from one another. The wiring comprises a plurality of second conductive layers extending upwardly from an upper surface of the first conductive layers comprising the stepped portion. The plurality of second conductive layers are formed such that upper ends thereof are aligned with a surface parallel to the substrate, and such that a diameter thereof decreases from the upper end thereof to a lower end thereof. The plurality of second conductive layers are formed such that the greater a length thereof in the perpendicular direction, the larger a diameter of the upper end thereof.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.