INTERFACIAL REACTIONS IN DYNAMICALLY HEATED SI ME/SI SANDWICH LAYERS/

Three sandwich layers of an Si/Me/Si structure, where Me = Al, Ni or C r, with a total thickness between 116 and 170 nm were sputter deposite d onto smooth silicon (111) substrates. Reactions of the metals with a morphous silicon thin films were activated in a differential scanning calorimeter, at a heating rate of 40 degrees C min(-1), between room t emperature and different higher temperatures. Auger electron spectrosc opy depth profiling of as-deposited and dynamically heat-treated sampl es enables the observation of the movment of Si-Me interfaces and the identification of the main migrating elements in the early stage of th e reaction. Formations of different reaction products are in agreement with the phases predicted by the effective heat of formation model af ter Pretorius.