The case for cryotronics?

Abstract

While cryotronics is, to some degree, a rather special technology, it has not been possible to show that cryogenic circuits possess, on balance, any functional advantages over circuits realizable in competitive technologies. Accordingly, the only real promise for cryogenics would seem to lie in the possible cost advantages which might, in principle, be realized through the batch manufacturing of large integrated circuit modules. That such an advantage can be realized in fact is, at present, somewhat problematic. The principal costs in the cryogenic technology are found to lie largely in five areas, namely: design, mask layout and checking; mask fabrication; circuit deposition; packaging; and refrigeration. A review of the steps required to carry out the construction and assembly of complete cryogenic processor indicates that, in terms of present technology, considerable cost reductions must be realized in each of the above areas if cryogenics is to be made commercially attractive. The current state of the cryogenic technology is reviewed and an attempt is made to project the cost structure which would appear to be realizable in the near future. It is appropriate, in presenting the case for cryogenics, to begin with two judgments which are, a priori, the basis for the central arguments which follow. A. The technical problems which need be solved in reducing the cryotronic technology to practice are, within reason, developmental rather than fundamental in nature, i.e., no fundamental "breakthroughs" or major innovations are believed to be required.