Soft X-ray emission spectroscopy (SXES) and photoemission electron microscopy (PEEM) were performed to study the solid phase reaction in the Ti(film)/Si(substrate) system with Mo interlayer. SXES is a suitable technique for non-destructive buried-layer characterization and is capable of qualitative analysis and chemical bonding state determination. PEEM is an imaging system for real-time observation of surface structures. The Si L-2,L-3 soft X-ray emission spectra of a Ti(50 nm)/Mo(12 nm)/Si(100) sample, annealed at 550 degreesC for 5 min, revealed formations of majority mixed species of C54-TiSi2 and MOSi2. Using PEEM imaging, the surface of a Ti(7.5 nm)/Mo(2.5 nm) bilayer film on Si(111) became rough due to the formation of some island-like structures after annealing to 500 degreesC. (C) 2004 Elsevier B.V. All rights reserved.