Interfacial reaction of a CVD WSi x polycide gate structure, WSi x (2200 Å)/polysilicon (4500 Å)/SiO2 (500 Å)/Si, has been studied by Rutherford backscattering spectroscopy technique. Annealing was done at temperatures of 900–1100°C in flowing dry N2. Slight interfacial reaction was observed at the WSi x -polysilicon interface with 1000°C annealing. At 1100°C annealing, however, in addition to this reaction, other reaction was also observed in gate oxide-polysilicon and/or gate oxide-substrate silicon interfaces. Composition of WSi x changed from nonstoichiometric (x=2.5) for as-deposited to stoichiometric (x=2.0–2.1) with annealing at temperatures above 900°C. Resistivity of CVD WSi x polycide layer was around 900 µΩ·cm for as-deposited, and decreased rapidly to 80, 60 and 42 µΩ·cm with 900, 1000 and 1100°C annealing, respectively.

Contact resistance of Al/Si Ohmic electrodes formed on boron implanted shallow p+ layers has been measured, where the annealing of ion implanted layers was performed by halogen lamp rapid heating at different temperatures ranging from 900°C to 1100°C. Contact resistance decreases gently with increasing temperature and becomes constant at above 950°C. Specific contact resistance of 1.5×10-7 Ohm-cm2 was attained at doses above 4×1015 cm-2 and at temperatures above 950°C. This value is very low and more than one order lower than that obtained by conventional furnace annealing. This contact is useful technology to fabricate high density and high speed MOS LSI.