Some novel applications of sputtering techniques for diffusion studies in solids

This article is written to honor Prof. Dr. Helmut Mehrer on the occasion of his 65th birthday for his leadership in the field of diffusion and the contributions he has made. An important area of his endeavor has been the measurements of small diffusion coefficients to investigate new materials invented during the last four decades. Because such measurements involve profiling of the diffusing species on a nanometer scale, radio frequency or DC ion gun sputtering has emerged as the principal technique. The sputtering techniques, as applied to diffusion studies, are briefly reviewed with a historical perspective. Several case studies of its application in diverse materials such as metals, alloys, oxides, semiconductors, the amorphous and quasicyrstalline metastable phases, and even metal atom diffusion in organic films are discussed. All these studies involve small diffusion coefficients, typically in the range of 10-16 to 10-24 m 2/sec, which would not have been possible without the use of the sputtering techniques.