Maskless lithography with sub-pixel resolution
US6717650B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | May 1, 2002 |
| Grant date | Apr 6, 2004 |
| Priority date | — |
| Expiry date | Jul 5, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70291
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Maskless microlithography provides a sub-pixel voting system using multiple, slightly-offset, digitally-controlled, unit-pixel, partial exposures with cumulative voting to identify regions of full exposure for sub-pixel-selection. Computer control of a virtual-mask pixel-selection device of unit-pixel resolution usually provides pixel-resolution patterns. To achieve sub-pixel resolution, the virtual mask, after a first partial exposure, is offset by less than a pixel-width and a second partial exposure is made. If the offset is ½ pixel-width, the result is a half-pixel size image region of full exposure. Finer voting can be defined by number of pulses, by significantly changing the offset, by offset in another dimension, and by increasing the multiplicity of exposures, thus enabling resolution enhancement by large multiples. The offsetting techniques can also be used to drill controlled-depth vias or to provide topography controls for laser-milling.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.