High density MOSFET array with self-aligned contacts delimited by nitride-capped trench gate stacks and method
US9136377B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 11, 2013 |
| Grant date | Sep 15, 2015 |
| Priority date | — |
| Expiry date | Mar 11, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/62
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A high density trench-gated MOSFET array and method are disclosed. It comprises semiconductor substrate partitioned into MOSFET array area and gate pickup area; epitaxial region, body region and source region; numerous precisely spaced active nitride-capped trench gate stacks (ANCTGS) embedded till the epitaxial region. Each ANCTGS comprises a stack of polysilicon trench gate with gate oxide shell and silicon nitride cap covering top of polysilicon trench gate and laterally registered to gate oxide shell. The ANCTGS forms, together with the source, body, epitaxial region, a MOSFET device in the MOSFET array area. Over MOSFET array area and gate pickup area, a patterned dielectric region atop the MOSFET array and a patterned metal layer atop the patterned dielectric region. Thus, the patterned metal layer forms, with the MOSFET array and the gate pickup area, self-aligned source and body contacts through the inter-ANCTGS separations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.