Formation of Titanium Nitride/Titanium Silicide by High Pressure Nitridation in Titanium/Silicon

Formation of a titanium nitride (TiN) layer by the nitridation of Ti in high-pressure (5.8 atm) ammonium (NH3) ambient is studied. A thick TiN layer is formed in high-pressure nitridation. Solid-phase silicidation reaction occurs at Ti/Si during the nitridation. When a thin Ti layer is nitrided in high-pressure NH3 for instance, a thicker TiN and thin TiSi2 multilayer structure, TiN(250 Å)/TiSi2(350 Å)/Si is formed. This structure is useful as a barrier metal for Al ohmic contact and for the adhesion layer in blanket tungsten.