Stability of Ta-Mo alloy on thin gate dielectric

박막 게이트 절연체 위에서 Ta-Mo 합금의 안정성

This paper investigated the stability of Ta-Mo alloy on thin gate dielectric. Ta-Mo alloy was deposited by using co-sputtering process after thermal growing of 3.4nm and 4.2nm silicon dioxide. When the sputtering power of Ta and Mo were 100W and 70W, respectively, the suitable work function for NMOS gate electrode, 4.2eV, could obtain. To prove interface thermal stability of thin film gate dielectric and Ta-Mo alloy, rapid thermal annealing was performed at $600^{\circ}C$ and $700^{\circ}C$ for 10sec in Ar ambient. The results of interface reaction were surveyed by change of silicon dioxide thickness and work function after annealing process. Also, the reliability of alloy gate and gate dielectric could be confirmed by quantity of leakage current. Ta-Mo alloy was showed low sheet resistance and thermal stability, namely, little change of gate dielectric and work function, after $700^{\circ}C$ annealing process.