Atomic transport in amorphous alloys: An introduction

The measurement of the diffusivities of metallic and metalloid species in amorphous alloys has necessitated the development of techniques capable of a resolution of a few nanometers over a total penetration depth of less than a micron. Various profiling techniques employing ion beams and the ultrasensitive multilayer technique are outlined. Generalities concerning the diffusion of different solutes in the same amorphous alloy or family of alloys, and the diffusion of the same solute in different amorphous alloys are presented, and the effect of solute concentration discussed. The role of amorphous alloys as diffusion barriers in microelectronic circuitry is outlined with emphasis on recent results. The influence of the nature of the substrate and metallic overlayer receives special attention. Barrier layers effective up to 700 °C have recently been made.