Browse Prior Art Database

Correcting Mask Deformations in X-ray Lithography

IP.com Disclosure Number: IPCOM000106959D
Original Publication Date: 1992-Jan-01
Included in the Prior Art Database: 2005-Mar-21
Document File: 1 page(s) / 31K

Publishing Venue

IBM

Related People

Bohlen, H: AUTHOR [+2]

Abstract

The invention concerns the problem that masks, such as those used in, e.g., X-ray lithography, may include deformations leading to defective circuits when the mask pattern is transferred to the wafer. In electron beam lithography, local deformations are corrected by suitably inclining the beam relative to the surface of the mask to be imaged. However, this approach is unsuitable for X-rays which are not as easily deflectable as electrons.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Correcting Mask Deformations in X-ray Lithography

       The invention concerns the problem that masks, such as
those used in, e.g., X-ray lithography, may include deformations
leading to defective circuits when the mask pattern is transferred to
the wafer.  In electron beam lithography, local deformations are
corrected by suitably inclining the beam relative to the surface of
the mask to be imaged. However, this approach is unsuitable for
X-rays which are not as easily deflectable as electrons.

      The invention proposes a novel mask structure with a mask
membrane fixed in an angular, preferably a rectangular, frame
composed of several, preferably four, sections, the lengths of which
are variable independently of each other. Each section length may be
adjusted, for example, piezoelectrically or thermally.  The changes
in the section lengths of the frame lead to additional membrane
deformation.  According to the invention, this additional deformation
is selected such that the original deformation is corrected.  In
addition, global correction using a single mask frame adjustment step
is proposed.  In that way, only a limited number of deformations are
accurately corrected.

      However, the proposed method may also be applied locally to
sequentially correct deformations at various places in the membrane
by different frame adjustments.