The formation of NiSi films on Si was studied using Rutherford backscatteri
ng spectrometry, atomic force microscopy, and ellipsometry. NiSi is an attr
active candidate for use as a gate contact material due to its low metal-li
ke resistivity and large processing window (350-750 degreesC). Three phases
, Ni2Si, NiSi, and NiSi2, were identified in this temperature range, and th
eir optical databases in the 2-4 eV photon range were established, and used
to model real-time ellipsometry data. It is shown that real-time ellipsome
try can be used to monitor and follow the formation of the various Ni-Si ph
ases. We have also observed the onset of agglomeration of the silicide for
longer time anneals at temperatures of 500-700 degreesC, which is much lowe
r than 1000 degreesC where agglomeration has been reported to occur. (C) 20
01 American Vacuum Society.