Tuning electrical performances of ALD TiO2-based thin film capacitor by Ar/O2 plasma-based atomic layer annealing

Obtaining crystalline thin films with low leakage current is crucial for realizing high-performance thin-film capacitors used in memories or passive devices. Here, we demonstrate a plasma-induced atomic layer annealing process that can induce the crystallization of TiO₂ thin films during atomic layer deposition, even at low temperatures. We show that atomic layer annealing using an Ar/O₂ mixed gas plasma can enhance the dielectric constant by promoting rutile phase crystallization while simultaneously maintaining or improving the leakage current. The effects of process parameters (pressure, power) on film and device performance are further investigated. As a result, the capacitor with an atomic layer-annealed TiO₂ dielectric film shows approximately a 30 % increase in capacitance while retaining a similar leakage current level on both Pt and Ru bottom electrodes.