Patterning Optical and X-Ray Masks for Integrated Circuit Fabrication.
Abstract
A layer of metal is deposited on a mask substrate and then covered with a layer of positive electron resist. A delineation of the peripheral boundaries of the desired mask geometry is carried out by means of a direct-write electron beam. Development and etching steps serve to remove the positive resist and the underlying metal in the beam-exposed peripheral boundaries. The mask is then raster scanned with a low intensity beam until a boundary is detected and then the beam intensity is increased significantly to a level sufficient to expose the positive resist. The scan and exposure continue until the mating peripheral boundary is detected and then the beam is rapidly decreased in intensity to its former low intensity level. The substrate is next developed to remove the positive resist subjected to the increased exposure-level beam intensity; and, the metal underlying this positive resist is then etched away. A final removal step serves to remove the remaining positive resist covering the substrate area outside of the geometry(s) circumscribed or delineated by said peripheral boundaries.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 14, 1987
- Accession Number
- ADD013486
Entities
People
- William B. Glendinning
Organizations
- United States Army