In this work, we studied molybdenum (Mo) and its conductive oxides (MoOx) for p-type metal gate application. Three compositions of MoOx have been investigated. The resistivity of Mo/MoOx was found to significantly increase with the oxygen incorporation. A clear phase separation of all MoOx compositions was observed after high-temperature thermal treatment. The incorporation of oxygen was found to be effective to increase the work function (WF) of Mo. However, after full device integration, a significant WF decrease of MoOx was observed, which may be induced during the high- temperature junction activation process. This high- temperature process also led to a significant interfacial silicon oxide layer growth for MoOx gated stacks. The equivalent oxide thickness dependent flatband voltage roll-off behavior and gate leakage will also be discussed. (C) 2008 The Electrochemical Society.