Atomic layer deposition of TiN films by alternate supply of tetrakis(ethylmethylamino)-titanium and ammonia

Atomic layer deposition (ALD) of amorphous TiN films on SiO2 between 170 degrees C and 210 degrees C has been investigated by alter nate supply of reactant sources, Ti[N(C2H5CH3)(2)](4) [tetrakis(ethylmethylamino)titanium:TEMAT] and NH3. Reactant sources were injected into the reactor in the following order:TEMAT vapor pulse, Ar gas pulse, NH3 gas pulse and Ar gas pulse. Film thickness per cycle was saturated at around 1.6 monolayers (ML) per cycle with sufficient pulse times of reactant sources at 200 degrees C. The results suggest that film thickness per cycle could exceed 1 ML/cycle in ALD, and are explained by the rechemisorption mechanism of the reactant sources. An ideal linear relationship between number of cycles and film thickness is confirmed. As a result of surface limited reactions of ALD, step coverage was excellent. Particles caused by the gas phase reactions between TEMAT and NH3 were almost absent because TEMAT was segregated from NH3 by the Ar pulse. In spite of relatively low substrate temperature, carbon impurity was incorporated below 4 at.%.