The Use of Radioisotopes in Lithographic Research.

An attempt has been made, in this paper, to show the applicability of tracer techniques to lithographic processes. Through a series of examples it has been shown that many measurements can be made that were difficult or impossible in the past. As a new tool for Iithography, then,its uses should be very wide. In the near future it can be expected that new isotopes will become available and broaden the scope of measurements. The important job at present, however, is not necessarily new measurements with the technique, but correlation of past measurements with actual practice. In a few cases this has been done and the results have been very encouraging. In any event it is felt that in radioisotope measurements lies the solution to many complex problems in Iithography. It is to be hoped that many more of these will come to light in the not too distant future.