THE ADJUSTMENT OF MOS TRANSISTOR THRESHOLD VOLTAGE BY ION IMPLANTATION

Abstract

Two new techniques have been demonstrated to set the threshold voltage of p‐channel MOStransistors and integrated circuits. Both processes employ ion implantation to alter the doping profile near the Si–SiO2 interface. The first centers the ion distribution at the interface while the second places it well inside the silicon. Thresholds may be modified from enhancement through depletion mode. Either method is compatible with standard MOS processes.