Browse Prior Art Database

Intensification of Photographic High Resolution Masks

IP.com Disclosure Number: IPCOM000092589D
Original Publication Date: 1966-Dec-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 1 page(s) / 11K

Publishing Venue

IBM

Related People

Clark, ER: AUTHOR [+2]

Abstract

When making photographic masks used in the fabrication of transistors, monolithic integrated circuits, and other semiconductor structures, lines and spaces of 0.2 mil width and smaller become hard to resolve with the use of optics alone. To maintain line width and spacing, and minimize this difficulty, normal or subnormal exposures of the photographic emulsion are made and an intensification process is applied to the mask image. Such results in the increased density of the image lines and no increase of density of underexposed spaces. After exposure, the silver image is intensified by a chemical reduction plating, an electroless deposition or similar technique.

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

Page 1 of 1

Intensification of Photographic High Resolution Masks

When making photographic masks used in the fabrication of transistors, monolithic integrated circuits, and other semiconductor structures, lines and spaces of 0.2 mil width and smaller become hard to resolve with the use of optics alone. To maintain line width and spacing, and minimize this difficulty, normal or subnormal exposures of the photographic emulsion are made and an intensification process is applied to the mask image. Such results in the increased density of the image lines and no increase of density of underexposed spaces. After exposure, the silver image is intensified by a chemical reduction plating, an electroless deposition or similar technique.

Silver, chromium, mercury, selenium, lead, uranium and copper salts are examples of metal salts which can be used to deposit their respective metals by the chemical reduction procedure. Electroless deposition can be accomplished using standard electroless plating solutions of nickel, gold and so forth.

1