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 ZrO₂ thin 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 N₂ for 60 s at 400 °C, 500 °C, or 600 °C. For the RTP at 400 °C, 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 ZrO₂ is 31 ± 2 after RTP treatment at 400 °C.