Wrap-around fin for contacting a capacitor strap of a DRAM
US9385131B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2012 |
| Grant date | Jul 5, 2016 |
| Priority date | — |
| Expiry date | Jan 11, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D86/215
Abstract
A conductive strap structure in lateral contact with a top semiconductor layer is formed on an inner electrode of a deep trench capacitor. A cavity overlying the conductive strap structure is filled a dielectric material to form a dielectric capacitor cap having a top surface that is coplanar with a topmost surface of an upper pad layer. A semiconductor mandrel in lateral contact with the dielectric capacitor cap is formed. The combination of the dielectric capacitor cap and the semiconductor mandrel is employed as a protruding structure around which a fin-defining spacer is formed. The semiconductor mandrel is removed, and the fin-defining spacer is employed as an etch mask in an etch process that etches a lower pad layer and the top semiconductor layer to form a semiconductor fin that laterally wraps around the conductive strap structure. An access finFET is formed employing two parallel portions of the semiconductor fin.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.