Improving performance and functional flexibility of thin film and semiconductor integrated circuits

Integrated circuits are superior to lumped component circuits in cost, reliability and size but inferior in flexibility. Their advantages have been proved in digital circuits where standard circuits may be used. For analogue applications and special circuits their use is at present limited by their lack of flexibility. This may be overcome by careful design in which the last step in processing is the function defining step and may be varied to suit circumstances. Microengraving by electron beam or laser gives flexibility in the making or cutting of connections at the end of the processing so that the costly tooling up may be enabled to yield a range of final circuits from the same substrate. It is suggested that in the future a 3-dimensional approach to integrated circuit design will evolve utilising bulk rather than junction properties and new techniques like ion implantation.