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 1 70 degrees C and 210 degrees C has been investigated by alter nate sup ply of reactant sources, Ti[N(C2H5CH3)(2)](4) [tetrakis(ethylmethylami no)titanium:TEMAT] and NH3. Reactant sources were injected into the re actor in the following order:TEMAT vapor pulse, Ar gas pulse, NH3 gas pulse and Ar gas pulse. Film thickness per cycle was saturated at arou nd 1.6 monolayers (ML) per cycle with sufficient pulse times of reacta nt sources at 200 degrees C. The results suggest that film thickness p er cycle could exceed 1 ML/cycle in ALD, and are explained by the rech emisorption mechanism of the reactant sources. An ideal linear relatio nship between number of cycles and film thickness is confirmed. As a r esult of surface limited reactions of ALD, step coverage was excellent . Particles caused by the gas phase reactions between TEMAT and NH3 we re almost absent because TEMAT was segregated from NH3 by the Ar pulse . In spite of relatively low substrate temperature, carbon impurity wa s incorporated below 4 at.%.