Self Aligned Nitridation of TiSi 2 : A TiN/TiSi 2 Contact Structure

Titanium nitride is an ideal barrier to silicon migration into aluminium metallisations in MOS devices. Various means by which a TiN,TiSi 2 contact structure can be achieved to give low resistivity interconnects and stable contacts are outlined. It is shown that TiN/ TiSi 2 contact structures self aligned to contact holes cut down to the TiSi 2 can be simply achieved. Results showing the stability of the nitride film against silicon diffusion are presented.