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:
Jul. 08, 1980
Filed:
Dec. 30, 1977
Constantino Lapadula, Mahopac, NY (US);
Burn J Lin, Katonah, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A photolithographic method wherein a mask is made by pattern exposing and developing a o-quinone diazide sensitized phenol-formaldehyde resist layer, the formed resist mask then being used directly as an exposure mask for a layer of deep ultraviolet (less than 3000A) sensitive resist such as an alkyl methacrylate resist. Since alkyl methacrylate resists are not sensitive to light above 3000A and phenol-formaldehyde resists are opaque to light below 3000A, phenol-formaldehyde resists may be used directly as photoexposure masks for alkyl methacrylate resists using any broad band exposure light source which includes deep ultraviolet. The direct use of a phenol-formaldehyde resist layer as an exposure mask for an alkyl methacrylate resist layer allows more flexible and practical use of resist exposure techniques, including fabrication of an etch resistant mask of high aspect ratio and high resolution without fabrication of an intermediate metallic mask from a material such as chromium.