A study on the mechanical behavior of the sputtered nickel thin films for UBM applications

Abstract

Nickel films of different thicknesses of 0.5 and 0.8 /spl mu/m were deposited by DC magnetron sputtering on the adhesion promoting Ta layer deposited on the silicon (100) wafer. The sputtering conditions used were 4 /spl times/ 10/sup -6/ base pressure; 3 /spl times/ 10/sup -1/ working pressure; 4 kW sputter power for 8 inch targets. The films were annealed in vacuum at temperature 200/spl deg/C and their elastic modulus and hardness were measured by nanoindentation technique (hysitron triboscope). Different load rates were used when indenting the samples. The influence of thickness and annealing temperature on the mechanical behaviour of nickel thin films is explored in the present work.