Composite silicon-metal nitride barrier to prevent formation of metal fluorides in copper damascene
US6372636B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 2000 |
| Grant date | Apr 16, 2002 |
| Priority date | — |
| Expiry date | Jul 1, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76855
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method of forming amorphous silicon spacers followed by the forming of metal nitride over the spacers in a copper damascene structure -single, dual, or multi-structure- is disclosed in order to prevent the formation of fluorides in copper. In a first embodiment, the interconnection between the copper damascene and an underlying copper metal layer is made by forming an opening from the dual damascene structure to the underlying copper layer after the formation of the metal nitride layer over the amorphous silicon spacers formed on the inside walls of the dual damascene structure. In the second embodiment, the interconnection between the dual damascene structure and the underlying copper line is made from the dual damascene structure by etching into the underlying copper layer after the forming of the amorphous silicon spacers and before the forming of the metal nitride layer. In the third embodiment, the ternary metal silicon nitride spacer is formed by etching after having first formed the amorphous silicon layer and the nitride layer, in that order, and then etching the passivation/barrier layer at the bottom of the damascene structure into the underlying copper layer. In all th…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.