The Clifford Paterson Lecture, 1986 - Limits of thin-film microfabrication

Abstract

Thin-film microfabrication techniques are used to make semiconductor integated circuits, integrated optical devices, thin-film magnetic recording heads, and a variety of other devices of commercial and scientific interest. The dimensional accuracy that can be achieved with the techniques frequently determines whether or not devices can be built, and it is almost always a major influence on device performance. In addition, the commercial viability of most devices depends on the cost, and the speed of the fabrication methods. This lecture discusses the practical and theoretical limits of thin-film fabrication processes. Emphasis is placed on ultraviolet light, X-ray, electron and ion lithographies. Ultimately, it is possible to build structures with dimensions of only a few atomic diameters. These so-called ‘nanostructures’ are being used in a variety of scientific investigations. Their fabrication, which is described, illustrates the limits to fabrication capability.