Photolithography methods and structures that reduce stochastic defects
US10782606B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 29, 2018 |
| Grant date | Sep 22, 2020 |
| Priority date | — |
| Expiry date | Feb 5, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/2004
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Disclosed are embodiments of a multi-layer stack and photolithography methods and systems that employ such a stack. The disclosed multi-layer stacks include a photoresist layer on an underlayer. The photoresist layer and underlayer are made of different materials, which are selected so that valence and conduction band offsets between the underlayer and photoresist layer create an effective electric field (i.e., so that the stack is “self-biased”). When areas of the photoresist layer are exposed to radiation during photolithography and the radiation passes through photoresist layer and excites electrons in the underlayer, this effective electric field facilitates movement of the radiation-excited electrons from the underlayer into the radiation-exposed areas of the photoresist layer in a direction normal to the interface between the underlayer and the photoresist layer. Movement of the radiation-excited electrons from the underlayer into the radiation-exposed areas of the photoresist layer improves photoresist layer development and pattern resolution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.