An integrated EPROM device which can be manufactured using standard high definition photolithographic techniques with unit cells of markedly reduced dimensions as compared to the minimum dimensions that can be achieved with the prior art, has field isolation structures between adjacent cells along rows of the array in the form of continuous isolation strips which extend for the whole column length of the array, thus avoiding the problems associated with photolithographic defining rectangular geometries. The electrical interconnection between the sources of the cells of each row is achieved by a special metal source "line", formed between two adjacent gate lines, using for the purpose a conformally deposited metal layer from which both the drain contacts and these source interconnection metal "lines" are created in a self-alignment way.