Amplification method for photoresist exposure in semiconductor chip manufacturing
US9709898B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 23, 2014 |
| Grant date | Jul 18, 2017 |
| Priority date | — |
| Expiry date | Jan 9, 2036 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/2041
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An electrical field is applied through an extreme ultraviolet (EUV) photoresist layer along a direction perpendicular to an interface between the EUV photoresist layer and an underlying layer. Secondary electrons and thermal electrons are accelerated along the direction of the electrical field, and travel with directionality before interacting with the photoresist material for a chemical reaction. The directionality increases the efficiency of electron photoacid capture, reducing the required EUV dose for exposure. Furthermore, this directionality reduces lateral diffusion of the secondary and thermal electrons, and thereby reduces blurring of the image and improves the image resolution of feature edges formed in the EUV photoresist layer. The electrical field may be generated by applying a direct current (DC) and/or alternating current (AC) bias voltage across an electrostatic chuck and a conductive plate placed over the EUV photoresist layer with a hole for passing the EUV radiation through.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.