Large-Scale Integration: What Is Yet to Come?

The rapid development of large-scale integrated circuits in the last two decades has revolutionized information handling. Higher levels of integration have been achieved principally by making the individual circuit elements smaller, but reduction of random defects and innovations in circuit design have also been important factors. Practical limits to the size of integrated circuits, such as those imposed by the use of photolithography to define the circuits, can be avoided by using other methods, such as solid-state diffusion or electron beams. The prospects are that dimensions and defect densities will continue to be reduced while speed increases. Redundancy in circuits will lead to lower costs and higher levels of integration. As logic becomes more complex and applications narrower, the increased number of unique circuit designs needed tends to increase costs. The microprocessor was developed to answer this problem and will have a radical influence on future computing systems.