Process of making semiconductor devices using photosensitive bodies
AssigneeBell Telephone Laboratories, Incorporated
InventorsEdwin A. Chandross, Elsa Reichmanis, Cletus W. Wilkins, Jr.
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Abstract
Photosensitive bodies that are sensitive to ultraviolet radiation and that exhibit excellent contrast are formed from base soluble polymers such as poly(methyl methacrylate-co-methacrylic acid) physically mixed with base insoluble materials such as o-nitrobenzyl esters. The base insoluble esters decompose upon irradiation to form base soluble entities in the irradiated regions. These irradiated portions are then soluble in basic solutions that are used to develop the desired image.
Claims11
A process for preparing a semiconductor device comprising the steps of depositing a photosensitive material on a substrate comprising a semiconductor material, irradiating said photosensitive material with electromagnetic radiation in a desired pattern, developing said pattern with an alkaline solution, and completing the fabrication of said semiconductor device wherein said photosensitive material comprises a mixture of an o-nitroarylmethyl ester of a carboxylic acid and a polymer which is soluble in said alkaline solution, said o-nitroarylmethyl ester being represented by the formula ##STR6## where R.sub.1 is a substituent chosen so that a salt of the carboxylic acid, R.sub.1 COOH, is sufficiently soluble in water to produce at least a 0.01 M solution and R.sub.1, R.sub.2, R.sub.3, and R.sub.4 are chosen so that the ratio expressed as 1:n of the solubility rate of said unexposed to said exposed portions is such that n is at least 4.
Dependencies are inferred from the claim text.