Matrix array of semiconducting elements

An integrated matrix array of semiconductive elements embedded in a substrate, the points of said array being defined by the intersection of parallel lines of a first set with parallel lines of a second set, said points being provided, or not provided, with said semiconductive elements which have a first electrode connected to a line of a first set and a second electrode connected to a line of a second set, the array being of the type in which the first electrodes of the semiconductive elements in each column or row are defined in a common sub-collector semiconductive region, the second electrodes being defined by contact with an epitaxial layer and provided only in positions in which a semiconductive element is to be operative, said array being arranged such that:

• (a) the semiconductive elements in each column or row are partitioned into groups of 2k elements;
• (b) in each group, said sub-collector semiconductive region and said epitaxial layer are selectively discontinuous, being partitioned into two portions, the first portion extending from one end of the group to the position having an operative semiconductive element closest to the mid-point of the group, and the second portion extending from the other end of the group to the position having an operative semiconductive element closest to the mid-point of the group;
• (c) connecting means extending between said ends of the two portions of said sub-collector semiconductive region in each group of semiconductive elements;
• (d) said substrate being of first conductivity-type, and in which in each group, said two portions comprise the semiconductive epitaxial layer and the common sub-collector semiconductive region, both of opposite conductivity-type, both portions being isolated by an isolation region of said first conductivity type.