Thermally stable, irradiation cross-linkable polymer systems based on bisphenols and epichlorohydrin

A method for generating a lacquer structure of the type employed in the manufacture of integrated semiconductor circuits in very large scale integration (VLSI) technology to serve as a mask in a process, wherein the surface of a semiconductor circuit is structured by selective etching and wherein the radiation crosslinkable polymer employed for building up said lacquer structure is produced by a polycondensate of a bisphenol and epichlorohydrin reacting with a compound having a light responsive group, the polycondensate having the structural formula:

• ##STR10## where:
• n is a positive whole number which ranges from 0 to about 30,
• X is a radical selected from the group consisting of hydroxymethylene and radicals of the structure:
• ##STR11## R is a lower alkyl radical Y is a radical selected from the group consisting of hydrogen, hydroxy-methylene, and radicals of the structure ##STR12## and wherein all said hydroxyl groups react with said compound, selected from the group consisting of cinnamoylchloride and furfurylacryloylchloride, the method comprising the steps of:
• (a) depositing a layer of said polymer on a semiconductor device;
• (b) imaging said layer through a mask;
• and
• (c) dissolving away all unimaged portions of said so imaged layer.

In a process for making a printed multi-layer circuit of the type where an electrically conductive metal layer is coated with a light-sensitive layer, and said layer is imaged through a mask having a negative image of the circuit pathways to be produced, and the so imaged layer is then developed with an organic solvent whereby unimaged portions of said so imaged layer are dissolved away, and whereby the residual portions of said so imaged and developed layer are thermally stable without post cure, the improvement comprises employing as said light-sensitive layer a radiation cross-linkable polymer produced by the reaction of a polycondensate reacting with a compound having a light responsive group, the polycondensate having the structural formula:

• ##STR13## where:
• n is a positive whole number which ranges from 0 to about 30,
• X is a radical selected from the group consisting of hydroxymethylene and radicals of the structure:
• ##STR14## R is a lower alkyl radical Y is a radical selected from the group consisting of hydrogen, hydroxy-methylene, and radicals of the structure ##STR15## and wherein all said hydroxyl groups react with said compound having a light responsive group, selected from the group consisting of cinnamoylchloride and furfurlacryloylchloride.