Three-dimensional memory devices having a shaped epitaxial channel portion
US9842851B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 2015 |
| Grant date | Dec 12, 2017 |
| Priority date | — |
| Expiry date | Oct 30, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3065
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An alternating stack of insulating layers and sacrificial material layers is formed over a substrate. A dielectric collar structure can be formed prior to formation of an epitaxial channel portion, and can be employed to protect the epitaxial channel portion during replacement of the sacrificial material layers with electrically conductive layers. Exposure of the epitaxial channel portion to an etchant during removal of the sacrificial material layers is avoided through use of the dielectric collar structure. Additionally or alternatively, facets on the top surface of the epitaxial channel portion can be reduced or eliminated by forming the epitaxial channel portion to a height that exceeds a target height, and by recessing a top portion of the epitaxial channel portion. The recess etch can remove protruding portions of the epitaxial channel portion at a greater removal rate than a non-protruding portion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.