Process for enhanced lithographic imaging
US6383719B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1998 |
| Grant date | May 7, 2002 |
| Priority date | — |
| Expiry date | May 19, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/095
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Fine feature lithography is enhanced by selectively providing exposures to correct for effects such as foreshortening, corner rounding, nested to isolated print bias, feature size dependent bias, and other image biases in semiconductor processing. These results are achieved by increasing the local exposure dose in critical areas of specific images, such as line ends and corners. The general process incorporates techniques which tailor the exposure dose as a function of position to achieve the desired final image shape. The techniques include contrast enhancement layers (CEL), scanning optical beams, and exposures with different masks. In one embodiment the process of forming a pattern comprises the steps of providing a substrate having a photosensitive coating, exposing the center area of the pattern on the photosensitive coating with one mask, and exposing ends of the pattern on the photosensitive coating without exposing the center area with a second mask. The second exposure overlaps the first exposure and may extend beyond the pattern but the second dose is much lower than the first dose.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.