Chemistries for etching multi-stacked layers
US11075084B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 2017 |
| Grant date | Jul 27, 2021 |
| Priority date | — |
| Expiry date | Aug 31, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/02123
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods for fabricating a 3D NAND flash memory are disclosed. The method includes the steps of forming a hardmask pattern on the hardmask layer, and using the hardmask pattern to form apertures in the alternating layers by selectively plasma etching the alternating layers versus the hardmask layer using a hydrofluorocarbon etching gas selected from the group consisting of 1,1,1,3,3,3-hexafluoropropane (C3H2F6), 1,1,2,2,3,3-hexafluoropropane (iso-C3H2F6), 1,1,1,2,3,3,3-heptafluoropropane (C3HF7), and 1,1,1,2,2,3,3-heptafluoropropane (iso-C3HF7), wherein the first etching layer comprises a material different from that of the second etching layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.