Self-aligned via process for preventing poison via formation
US6013579A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 21, 1998 |
| Grant date | Jan 11, 2000 |
| Priority date | — |
| Expiry date | Oct 21, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76897
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A self-aligned via process to prevent the via poisoning includes forming a hydrogen silsesquioxane layer on the substrate and over a pre-formed metal layer, forming an etching stop layer on the hydrogen silsesquioxane layer, forming an oxide layer on the etching stop layer, and then proceeding with a two-step etching process to form a via. The two-step etching process first patterns the oxide layer using a patterned photoresist layer as a mask, and then patterns the etching stop layer together with the hydrogen silsesquioxane layer using the patterned oxide layer as a mask. Because the etching stop layer prevents the hydrogen silsesquioxane layer from reacting with the oxygen plasma during the photoresist layer removal process, via poisoning is eliminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.