Development of silicon single-electron devices

We have developed a novel method called pattern-dependent oxidation (PADOX) for fabricating small Si single-electron transistors (SETs) and used it to make many kinds of SEDs. One of the most primitive and important features of the method is that fabricated devices operate quite stably for long-term drift. By using the method we have demonstrated various kinds of logic devices. SETs have two unique features that conventional transistors do not have. One is multi-input gates capability, and the other is oscillatory conductance as a function of gate voltage. We have exploited these features to achieve complicated functions, such as an adder and a multiple-valued memory.