Characterization of Low-Temperature Stress Hump in Relation to Phase Formation Sequence of Nickel Silicide

The stress hump phenomenon observed at a low temperature of approximately 140°C during in situ stress-temperature measurement of sputtered Ni thin film on a (001) Si substrate has been investigated. We found that the stress hump was not related to the formation of NiSi 2 , but originated from the thickening of an amorphous Ni–Si intermixing layer in the temperature range of 100–140°C followed by the formation of the Ni 2 Si phase at temperatures above 140°C.