Test structure for determining a region of a deep trench outdiffusion in a memory cell array

A test structure for determining a doping region of an outer capacitor electrode of a trench capacitor in a memory cell array. The trench capacitors of the memory cell array are arranged in matrix form. The test structure has two parallel rows of trench capacitors. The outer capacitor electrode of each row of trench capacitors is electrically connected to one another and the basic area of at least one trench capacitor of each row is lengthened on the side facing the other row in such a way that the two trench capacitors overlap in a direction transverse to their extent.