THE EFFECTS OF DEPOSITION TEMPERATURE ON THE INTERFACIAL PROPERTIES OF SIH4 REDUCED BLANKET TUNGSTEN ON TIN GLUE LAYER

Low pressure chemical vapor deposition tungsten films were deposited a t various temperatures, using a WF6-SiH4-H-2 gas mixture. The impurity distribution at the W/TiN interface was investigated by Auger electro n spectroscopy depth profiling. Some fluorine accumulation at the inte rface is observed when the tungsten is deposited below 300-degrees-C. However, above 300-degrees-C, no accumulation of fluorine could be obs erved. A result obtained from thermodynamic calculations using SOLGASM IX-PV suggests that this phenomenon is closely associated with the hig hly oxidized surface layer of TiN at the initial stage of deposition. The reaction of the gas mixture with the TiN surface layer seems to en hance the fluorine accumulation, which lowers the adherence of the int erface and increases the contact resistance.