Effect of annealing on adhesion for Ti/Ni/Ag electrodes

Compared with traditional single nickel layer electrode, multilayers electrode for backside chips of power devices has higher thermal and electrical reliability. In this paper, Ti/Ni/Ag metal trilayers were deposited on single crystal silicon (111) substrates by DC magnetron sputtering technique. The effect of thermal treatment on adhesion strength of multilayers electrodes was investigated with the help of SEM, XRD, AFM, and EDX measurement. The analysis results showed that the annealing temperature and time had strong influence on adhesion. The optimal annealing conditions were 600 °C for 60 min. Samples treated under the conditions exhibited the highest adhesion strength of 134.4 N/cm
²
with more smooth surface and higher metallization degree, which fits for the requirement of the general power devices.