Low roughness EUV lithography
US9922839B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 22, 2016 |
| Grant date | Mar 20, 2018 |
| Priority date | — |
| Expiry date | Jun 22, 2036 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32137
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Provided herein are methods and related apparatus to smooth the edges of features patterned using extreme ultraviolet (EUV) lithography. In some embodiments, at least one cycle of depositing passivation layer that preferentially collects in crevices of a feature leaving protuberances exposed, and etching the feature to remove the exposed protuberances, thereby smoothing the feature, is performed. The passivation material may preferentially collect in the crevices due to a higher surface to volume ratio in the crevices than in the protuberances. In some embodiments, local critical dimension uniformity (LCDU), a measure of roughness in contact holes, is reduced. In some embodiments, at least one cycle of depositing a thin layer in a plurality of holes formed in photoresist, the holes having different CDs, wherein the thin layer preferentially deposits in the larger CD holes, and anisotropically removing the thin layer to remove it at the bottoms of the holes, is performed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.