Exposure method and apparatus using holographic techniques
US5504596A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1993 |
| Grant date | Apr 2, 1996 |
| Priority date | — |
| Expiry date | Dec 20, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H1/2249
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
An exposure apparatus is used for reproducing a mask pattern of a semiconductor device or the like onto a photosensitive substrate using a holography. The holography is utilized also in a process for alignment between a mask pattern hologram and an exposure region of the substrate. The pattern hologram is recorded to a recording medium by interference between an object wave from the pattern and a reference wave, and a second hologram is formed to the medium by diffraction light from an alignment mark formed on the mask. Prior to reconstruction of the pattern image, reconstruction light from the second hologram, illuminated with a reconstruction wave, is irradiated onto the substrate arranged in place of the mask. A reproduction image of the alignment mark on the substrate surface illuminated with the reconstruction light is measured, and relative displacement between the medium and the substrate is detected from a result of the measurement. The relative positional relationship between the medium and the substrate is corrected in accordance with the displacement information, and, thereafter, the surface is exposed with a reconstruction image of the pattern hologram.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.