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A b s t r a c t Thermally stable dual work function metal gates are demonstrated using a conventional CMOS process flow. The gate structure consists of poly-Siimetal nitrides (MNJ SiON (or highk)iSi slack with atomic layer deposition (ALD)-TaN, for thc NFET and ALD-WN, for the PFET. Much enhanced dnve current (Id) and transconductance (G,) values, and reduced off current (Ion) characteristics were attained with ALD-MN, gated devices over control poly-Si and PVD-MN, devices within controllable V, shifts. Excellent scalability of dual work function MN,ihigh-k gate stack was demonstrated the EOT was down to 6.68, with low leakage in a low thermal budget device scheme. IntroductionWith aggressive scaling of CMOS devices, it is imperative to replace poly-Si gates by metal gates to eliminate poly-depletion. The most desired metal gates should possess work functions close to Si band edges for CMOSFETs. More importantly, these metal gates should be thermally stable to employ a conventional process flow for fabrication; however, it is extremely challenging to identify two thermally stable metal gates with the correct work functions [1,2]. Furthermore, lhe method of preparing the metal gates is critical due

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