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

Abstract

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