Capacitance Voltage Characteristics Of Stearic Acid Insulating Films In Mis Devices

Abstract

Fatty acid films may provide a good substitute as dielectric medium for MIS (metal-insulator-semionductor) technology. This paper discusses capacitance vs voltage (C-V) characteristics of metal/stearic acid/semiconductor devices formed on p-type silicon with thin native silicon dioxide (Si/sub 2/) layers. Variable frequency C-V plots display anomalous frequency dispersion in the negative bias voltage region and a reduction of the dispersion in the positive bias region. This can be attributed to the formation of interface states at the SiO/sub 2//stearic acid insulator boundary. C-V characteristics of MIS samples which have been subjected to thermal stress are also discussed. In these studies we have observed both a voltage and capacitance shift with respect to the unstressed specimens. The observed voltage shift is presumably due to the presence of mobile space charges moving to the SiO/sub 2//stearic acid boundary. The shift in capacitance in the stressed samples may have been caused by annealing of stearic acid films when they undergo thermal stress.