Microstructuring in semiconductor technology

The dynamic 4 Mbit RAM represents the first generation of integrated circuits, which contains sub-mym-structures. This requires high demands on the microstructuring technique. On the one hand very fine structures have to be fabricated into resist films by lithography and on the other hand these fine structures have to be tranfered to the underlying layer with optimum dimension control. In the production of integrated circuits at present the generation of resist pattern is carried out mostly by means of optical lithography. But the limits of this type of lithography are within sight. Therefore alternatives such as x-ray, electron- and ion beam lithography are in development. These types of lithography allow the generation of sub-0.5mym-structures. The present state of lithography will be discussed in this paper. The transfer of the resist pattern into the layer below is carried out by means of plasma assisted etching. Thereby a chemical etch reaction is induced by impinging ions. The ac tual state and further developments of etch processes will be discussed.