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Thermal stabilities of various metal bottom electrodes were examined by using a Ta2O5 metal-oxide-metal (MOM) capacitor struc-ture. After depositing 10-nm thick Ta2O5 on metal-electrode/poly-Si, we performed rapid thermal oxidation (RTO) at 850.C for 60 s inan O2 ambient. A chemical-vapor-deposition (CVD) WSi2 electrode showed satisfactory thermal stability after the RTO, while otherexamined electrode materials exhibited thermal degradation caused by oxidation failure or interfacial reaction between the substratepoly-Si and the Ta2O5. After post-annealing at 650.C for 30 min (in N2 condition) with CVD TiN top electrode, an eective oxide thick-ness (Tox) o f. 32 A˚and a leakage current density of. 107 A/cm2 at 1.25 V were obtained from the MOM capacitor with the WSi2 bot-tom electrode. Other electrode materials, such as TiN, TiSix, W Nx, W, and Ta, were severely oxidized during the RTO in the MOMstructures, and very poor capacitor properties were obtained in terms ofTox and leakage current.