Interpretation of a non-conventional reverse-current curve of a depletion-type gate-controlled diode

This work deals with the reverse-current characteristics of an nMOS gate-controlled diode with an implanted N type layer at the surface of the channel. Two possible forms of the characteristics curve, which can be obtained depending on the final material quality (lifetime and surface generation velocity) and on the silicon surface doping level, are discussed. An experimental nonconventional curve and its interpretation are presented. An estimated surface generation velocity was calculated by means of Pierret's correction procedure and a value of approx. 1 cm/sec was obtained.