Elevationally-extending strings of memory cells individually comprising a programmable charge storage transistor and methods of processing silicon nitride-comprising materials
US10381377B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 20, 2018 |
| Grant date | Aug 13, 2019 |
| Priority date | — |
| Expiry date | Jul 20, 2038 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D30/683
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method comprises forming material to be etched over a substrate. An etch mask comprising a silicon nitride-comprising region is formed elevationally over the material. The etch mask comprises an elevationally-extending mask opening in the silicon nitride-comprising region that has a minimum horizontal open dimension that is greater in an elevationally-innermost portion of the region than in an elevationally-outermost portion of the region. The elevationally-outermost portion has a greater etch rate in at least one of HF and H3PO4 than does the elevationally-innermost portion. The etch mask is used as a mask while etching an elevationally-extending mask opening into the material. The silicon nitride-comprising region is exposed to at least one of HF and H3PO4 to increase the minimum horizontal open dimension in the elevationally-outermost portion to a greater degree than increase, if any, in the minimum horizontal open dimension in the elevationally-innermost portion. Other aspects and embodiments, including structure independent of method of manufacture, are disclosed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.