Atomic Layer Deposition of Ru Thin Films Using 2,4-(dimethylpentadienyl)(ethylcyclopentadienyl) Ru by a Liquid Injection System

摘要

Ru thin films were grown on TiO2/Si and bare-Si substrates by atomic-layer-deposition using 2,4-(dimethylpentadienyl)(ethylcyclopentadienyl) Ru and O2 as Ru precursor and reactant, respectively. Negligible RuO2 was formed even with an excessive oxygen dose. Ru films on TiO2/Si substrate showed smoother surface morphology compared to Ru films on bare-Si substrate. Although abnormal grain growth of Ru films appeared at annealing temperature ≫ 700掳C, agglomeration of Ru films was not observed. Al-incorporated TiO2 (ATO) films were grown on Ru films and the electrical properties of the capacitor were investigated in order to evaluate the properties of bottom Ru films. The leakage current density of an ATO film with an equivalent oxide thickness of 0.7 nm was 10-7 A/cm2 at + IV. Therefore, Ru films grown by ALD are very promising as the capacitor electrodes of future dynamic random access memories.