The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 01, 1991
Filed:
Feb. 07, 1989
Hitachi, Ltd., Tokyo, JP;
Abstract
When a pattern is to be fabricated by a lithography using radiation on a heavy metal layer formed on a substrate, secondary electrons are generated in a diverging form from the heavy metal layer by irradiation with a radioactive ray to expose the resist. As a result, the accuracy of the pattern to be formed on the resist is reduced. In order to prevent this, a layer to be transferred, a substrate to be worked, a mask and so on are formed with a film capable of absorbing the secondary electrons so that secondary electrons generated from the heavy metal layer may not reach the resist film. Although a pattern having a thickness of 2 microns or less could not be fabricated according to the prior art, a pattern as thin as 1.5 microns can be fabricated by the method of the present invention.