LOCALIZED ANODIC OXIDE-FILMS ON SI - PREPARATION AND PROPERTIES

The anodic oxidation of silicon in a 0.04 N solution of potassium nitr ate in ethylene glycol with small amounts of water is a hole consuming process. Therefore, n-type silicon, anodically biased, behaves in the dark in many respects as a reverse biased diode. Under steady-state c onditions a certain, in general a very low electrochemical reaction ra te is established. If the sample is locally implanted with ions or loc ally illuminated the ion implanted or illuminated regions can serve as an additional source of minority carriers and show a faster oxidation rate than the nonimplanted or nonilluminated areas. The influence of radiation damage as well as of a focused laser beam (radius 4 mum) on the local oxidation of anodically biased n-type silicon is discussed. The electrophysical properties of the silicon/anodic oxide interface a re investigated by forming Metal/Oxide/Semiconductor (MOS) structures.