Self sealed aligned contact incorporating a dopant source
US5216281A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 26, 1991 |
| Grant date | Jun 1, 1993 |
| Priority date | — |
| Expiry date | Aug 26, 2011 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
- 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 A remnant (60a) of a doped silicon layer overlies the S/D 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. The doped silicon acting as a dopant for the source/drain region. A 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 doped silicon to enclose the top and sides of the gate electrode with nitride. The bottom of the contact is formed by the doped silicon at some locations and by the nitride at other locations. The contact sidewall through the thick dielectric preferably overlies the Si.sub.3 N.sub.4 but not the doped silicon. The doped silicon is effective as a dry etch stop and a wet etch stop, and the silicon nitride is effective as an isotropic etch stop. The doped silicon is wholly contained within the contact, an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.