Patent · US Expired

Undercut membrane mask for high energy photon patterning

US5326426A · kind A · utility

39Cited by

7References

39Claims

0Family size

Inventors

Andrew Ching Tam · Saratoga, US
Gerhard E. Wolbold · Magstadt, DE
Werner Zapka · Gärtringen, DE

Key dates

Filing date	Nov 14, 1991
Grant date	Jul 5, 1994
Priority date	—
Expiry date	Nov 14, 2011

Classification

Technology area (CPC Y)Emerging Cross-Sectional Technologies
CPC primaryY10T428/24322
WIPO fieldOptics
WIPO sectorInstruments

Abstract

A mask for use with high energy radiation sources in precision projection processing by excimer lasers, for example, is described. The mask comprises a suitable substrate, such as silicon, upon which a multilayer dielectric stack is formed which acts as a reflective coating for the impinging excimer laser radiation, minimizing energy absorption by the mask substrate. The mask transparent areas are defined by the through-holes in the mask. The through-holes are formed with a conically undercut edge profile to define a thin object plane for the mask and minimize scattering of the radiation from the through-hole sidewalls. A method for fabricating the mask is also described.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.