Method for etching low k dielectrics
US6547977B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 5, 2000 |
| Grant date | Apr 15, 2003 |
| Priority date | — |
| Expiry date | Nov 5, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31138
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
The present disclosure pertains to a method for plasma etching of low k materials, particularly polymeric-based low k materials. Preferably the polymeric-based materials are organic-based materials. The method employs an etchant plasma where the major etchant species are generated from a halogen other than fluorine and oxygen. The preferred halogen is chlorine. The volumetric (flow rate) ratio of the halogen:oxygen in the plasma source gas ranges from about 1:20 to about 20:1. The atomic ratio of the halogen:oxygen preferably falls within the range from about 1:20 to about 20:1. When the halogen is chlorine, the preferred atomic ratio of chlorine:oxygen ranges from about 1:10 to about 5:1. When this atomic ratio of chlorine:oxygen is used, the etch selectivity for the low k material over adjacent oxygen-comprising or nitrogen-comprising layers is advantageous, typically in excess of about 10:1. The plasma source gas may contain additives in an amount of 15% or less by volume which are designed to improve selectivity for the low k dielectric over an adjacent material, to provide a better etch profile, or to provide better critical dimension control, for example. When the additive co…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.