Method for formation of contact plugs utilizing etchback
US5231051A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 1, 1991 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | Oct 1, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/976
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An improved planarity when forming contact plugs by a blanket CVD deposition of a metallic matrix layer followed by etchback is achieved by performing a first etchback step to expose the surface of the dielectric material underlying the filling metal layer, while masking the top of the metal plugs with resist caps. The resist caps are formed using a mask derived by field inversion and enlargement from the actual contact mask used for defining the contact areas. With the resist caps covering the contact plugs, the filling metallic material is overetched to eliminate residues along with discontinuities from the planarity of the surface, while shielding the top of the plugs from the overetch. The masked overetch is preferably conducted under conditions of reduced anisotropy and increased selectivity in respect to the first etchback step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.