TiN/ZrO₂/Ti/Al Metal–Insulator–Metal Capacitors With Subnanometer CET Using ALD-Deposited ZrO₂ for DRAM Applications

We provide the first report of the structural and electrical properties of TiN/ZrO2/Ti/Al metal-insulator-metal capacitor structures, where the ZrO2thin film (7-8 nm) is deposited by ALD using the new zirconium precursor ZrD-04, also known as Bis(methylcyclopentadienyl) methoxymethyl. Measured capacitance-voltage (C-V) and current-voltage (I-V) characteristics are reported for premetallization rapid thermal annealing (RTP) in N2for 60 s at 400degC, 500degC, or 600degC. For the RTP at 400degC, we find very low leakage current densities on the order of nanoamperes per square centimeter at a gate voltage of 1 V and low capacitance equivalent thickness values of ~ 0.9 nm at a gate voltage of 0 V. The dielectric constant of ZrO2is 31 plusmn 2 after RTP treatment at 400degC.