Three-dimensional memory device containing self-aligned bit line contacts and methods for forming the same
US11935784B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 2021 |
| Grant date | Mar 19, 2024 |
| Priority date | — |
| Expiry date | Jul 16, 2042 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10B43/50
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A vertical layer stack including a bit-line-level dielectric layer and an etch stop dielectric layer can be formed over an array region. Bit-line trenches are formed through the vertical layer stack. Bit-line-trench fill structures are formed in the bit-line trenches. Each of the bit-line-trench fill structures includes a stack of a bit line and a capping dielectric strip. At least one via-level dielectric layer can be formed over the vertical layer stack. A bit-line-contact via cavity can be formed through the at least one via-level dielectric layer and one of the capping dielectric strips. A bit-line-contact via structure formed in the bit-line-contact via cavity includes a stepped bottom surface including a top surface of one of the bit lines, a sidewall segment of the etch stop dielectric layer, and a segment of a top surface of the etch stop dielectric layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.