Preparation of SrRuO\u3csub\u3e3\u3c/sub\u3e films for advanced CMOS metal gates

Abstract

\u3cp\u3eWe report on the growth and properties of SrRuO\u3csub\u3e3\u3c/sub\u3e films for application as metal gates for CMOS devices. The films were grown at 500°C by metal-organic chemical vapour deposition on Si substrates with thermal SiO\u3csub\u3e2\u3c/sub\u3e, atomic-layer deposited Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e and HfO \u3csub\u3e2\u3c/sub\u3e dielectric films. The films exhibit room temperature resistivity below 1 mΩ cm. We have analysed the interface between the SrRuO \u3csub\u3e3\u3c/sub\u3e metal gate and the oxide film by Rutherford backscattering and secondary ion mass spectroscopy. Annealing in an oxygen atmosphere and forming gas (90% N\u3csub\u3e2\u3c/sub\u3e +10% H\u3csub\u3e2\u3c/sub\u3e) were employed for testing the stability of the SrRuO\u3csub\u3e3\u3c/sub\u3e metal gate. Finally, electrical characteristics of the metal gate stack were investigated by high-frequency capacitance-voltage measurements. The properties of metal-organic chemical vapour grown SrRuO\u3csub\u3e3\u3c/sub\u3e gate electrode are analysed with regards to integration in CMOS devices.\u3c/p\u3