Method for producing a semiconductor fixed value rom

Abstract

A method for producing a fixed value memory (Read only memory, ROM) in the form of a programmable, monolithically integrated circuit, in which the fixed information is introduced into a semiconductor memory as binary coded bit pattern in process stages integrated into or following the conventional production sequence for semiconductor circuits including the direct transfer of the occupation of the memory cells, as prepared by software, with the elimination of masks. An electron or ion beam, which is deflected by means of deflecting means under the control of a computer is used to produce a mask on the surface of the semiconductor memory to correspond to the coded bit pattern, and thereafter, by selective process steps, the memory cells of the memory circuit below are caused to receive the desired stored value.