EFFECT OF POSITIVE IONIC SPACE CHARGE ON ELECTRICAL CAPACITANCE AND SCHOTTKY CURRENT IN THIN AL2O3 FILMS

The electrical capacitance and Schottky electron emission of Al-Al2O3-Al sandwiches, with oxide films ranging in thickness from 60 to 700 Å, have been measured before and after an aging process. The results are interpreted in terms of a positive ionic space charge which is present in the Al2O3 films and which vanishes during the aging process. The spatial distribution of positive ions within an oxide film has been investigated. Two methods for calculating the positive space charge density from the Schottky characteristic are described. © 1969.