Highly integrated MOS memory units prodn. - is performed so that distances between mask edges in two masks are independent from each other

摘要

The unit (1) is produced by the use of silicon-gate technology, by which troughs are etched in an oxide layer on a substrate, in which switching circuits are produced. Zones between the troughs are produced, in which the substrate is doped through a first mask in order to obtain electric insulation. Then the troughs are etched in the oxide layer using a second (trough) mask. The distance between adjacent mask edges is in the trough mask independent from the distance of adjacent mask edges inside the first mask. It is determined only by the required distance between adjacent troughs, while the mask edges in the first mask are spaced only in accordance with the minimum distance required by the mask production.