The origin of the development of integrated circuits up to VLSI is found in the invention of the transistor, which made it possible to achieve the ac- tion of a vacuum tube in a semiconducting solid. The structure of the tran- sistor can be constructed by a manufacturing technique such as the intro- duction of a small amount of an impurity into a semiconductor and, in ad- dition, most transistor characteristics can be improved by a reduction of dimensions. These are all important factors in the development. Actually, the microfabrication of the integrated circuit can be used for two purposes,...