Etching method for reducing microloading effect
US9443741B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 24, 2015 |
| Grant date | Sep 13, 2016 |
| Priority date | — |
| Expiry date | Jun 24, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/31058
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An etching method includes forming a high density structure and a low density structure on a substrate. A first material layer is formed to cover both structures. Part of the low density structure is exposed through the first material layer. A second material layer is formed to cover the first material layer. The second material layer is etched to remove the second material layer on the high density structure and part of the second material layer on the low density structure. The first material layer on the high density structure and the second material layer on the low density structure are simultaneously etched. The first material layer is etched to expose a first portion of the high density structure and a second portion of the low density structure. Finally, the first portion and the second portion are removed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.