Maskless lithography with multiplexed spatial light modulators
US6870554B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jan 7, 2003 |
| Grant date | Mar 22, 2005 |
| Priority date | — |
| Expiry date | Oct 16, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03F7/70291
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Imaging systems that use a spatial light modulator (SLM), such as maskless lithography systems using a digital micromirror device (DMD), suffer from low throughput at high resolution because of the increase in the number of pixels to be imaged. A possible solution to this problem is provided by using multiple SLMs. However, packaging multiple SLMs on a suitable base is inefficient because, in an SLM, surrounding the active region, a large inactive region is required for the chip kerf and the connector fan-in; these inactive regions thus prevent close packing of the SLMs. This invention enables close packing of a large number of SLMs by arranging them in twin planes, such that the kerf and fan-in regions overlap substantially. Variations in the optical conjugate distances of different SLMs caused by the twin planarity are eliminated by incorporation of a twin-pane compensating mirror array that corresponds to the SLM array, and introduces a pathlength difference between different mirrors that is complementary to the pathlength difference between corresponding SLM chips. Depth-of-focus problems are thus eliminated. The invention enables significant throughput enhancement, up to 82%, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.