KINETICS OF THIN-FILM REACTIONS OF CU A-GE BILAYERS/

The kinetics of the Cu3Ge phase formation during reactions between 600 nm polycrystalline Cu (poly-Cu) and 600 nm amorphous Ge (a-Gel layers on Si (100) substrates have been studied as a function of annealing c onditions. Monoclinic Cu3Ge nucleated rapidly, resulting in smooth Cu3 Ge layers. The room-temperature resistivity of the Cu3Ge was similar t o 8 mu Omega cm (similar to 4.5 times that of pure Cu). The real-time resistance versus temperature [R(T)] characteristics were nearly ident ical for heating rates of 0.1-5 degrees C/min. Modeling of the R(T) da ta indicates that the reaction was predominantly diffusion controlled with a rate of (4 X 10(-3) cm(2)/S) exp [-085 +/- 0.01 eV/kT] where k = 8.617 X 10(-5) eV/K. Secondary ion mass spectrometry profiles and R( T) data for the films annealed to various temperatures indicate that t he Cu3Ge/Ge interface is stable for T < 300 degrees C. (C) 1997 Americ an Institute of Physics.