Spectromicroscopy of silicide phases formed at NirSi interfaces

NirSi interfaces, produced at temperatures below 920 K.and above 1170 K.the Ni solvus line in Si have been studied by means of synchrotron radiation scanning photoelectron microscopy with spatial resolution of 0.12 mm. The lateral distribution and composition of the formed two- 2D. and three-dimensional 3D. Ni silicide phases of micron-sized dimensions were examined. The Ni 3p chemical maps and the Si 2p, Ni 3p and valence band spectra revealed unexpected coexistence of NiSi- and NiSi2-like islands with distinctive shapes and orientations. The formation of these two types of islands is a common feature for both interfaces. The main difference between the interfaces was in the spatial distribution of Ni outside of the islands which showed the development of a Ni-deficient zone in the vicinity of the islands, the formation of which was favored at temperatures above the Ni solvus line. q1999 Elsevier Science B.V. All rights reserved