Sealed self aligned contacts using two nitrides process
US5043790A · kind A · utility
Assignees
Inventor
Key dates
| Filing date | Apr 5, 1990 |
| Grant date | Aug 27, 1991 |
| Priority date | — |
| Expiry date | Apr 5, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/97
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In a contact structure to a source/drain region (28) nearby a gate electrode (22), a contact sidewall through a thick dielectric is laterally displaced away from the S/D region to widen the contact; the contact sidewall is located over the gate electrode. Titanium silicide (34) is located upon the S/D. A remnant (36a) of a (conductive) TiN layer overlies the silicide and rises up along the sidewall of gate electrode insulation and onto insulation atop the gate electrode, and is insulated from the gate electrode thereby. A further nitride, preferably Si.sub.3 N.sub.4, is located under the thick dielectric and over part of the gate electrode insulation. The Si.sub.3 N.sub.4 adjoins the TiN to enclose the top and sides of the gate electrode with nitride. The bottom of the contact is formed by one nitride at some locations and by the other nitride at other locations. The contact sidewall through the thick dielectric preferably overlies the Si.sub.3 N.sub.4 but not the TiN. The TiN is effective as a dry etch stop and a wet etch stop, and the silicon nitride is effective as an isotropic etch stop. The conductive nitride is wholly contained within the contact, and the further nitride exte…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.