X-ray lithography using holographic images
US5455850A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1991 |
| Grant date | Oct 3, 1995 |
| Priority date | — |
| Expiry date | Nov 1, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03H2001/0094
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A non-contact X-ray projection lithography method for producing a desired X-ray image on a selected surface of an X-ray-sensitive material, such as photoresist material on a wafer, the desired X-ray image having image minimum linewidths as small as 0.063 .mu.m, or even smaller. A hologram and its position are determined that will produce the desired image on the selected surface when the hologram is irradiated with X-rays from a suitably monochromatic X-ray source of a selected wavelength .lambda.. On-axis X-ray transmission through, or off-axis X-ray reflection from, a hologram may be used here, with very different requirements for monochromaticity, flux and brightness of the X-ray source. For reasonable penetration of photoresist materials by X-rays produced by the X-ray source, the wavelength X, is preferably chosen to be no more than 13.5 nm in one embodiment and more preferably is chosen in the range 1-5 nm in the other embodiment. A lower limit on linewidth is set by the linewidth of available microstructure writing devices, such as an electron beam.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.