Controlling the titanium silicide penetration into the polysilicon during oxidation of TiSi2/polysilicon structures

It was found that during the oxidation of a titanium silicide/polysilicon structure, there is non-uniform consumption of the underlying polysilicon resulting in spiking of the silicide into the polysilicon layer. To eliminate this problem a layer of 400-600 Å of a-Si was deposited in situ just prior to the deposition of the silicide, on top of the n⁺polysilicon layer. This structure did not show any spiking for a 60-min oxidation at 950°C in dry O2.