Chemical structures and electrical properties of atomic layerdeposited HfO2thin films grown at an extremely low temperature(≤100◦C) using O3as an oxygen sourceJeong

Abstract

The properties of atomic layer deposited (ALD) HfO2films grown at low temperatures (≤100◦C) wereexamined for potential applications in flexible display and bioelectronics. A saturated ALD growth behav-ior was observed even at an extremely low temperature (30◦C) due to the strong oxidizing potential of O3.However, HfO2films grown at low temperatures showed a low film density and high impurity concentra-tion, because the thermal energy during film growth was insufficient to remove ligands completely fromHf ions in precursor molecule. This resulted in low dielectric constant and high leakage current densityof the films. Nevertheless, HfO2film grown at 100◦C using O3gas with a high concentration (390 g/Nm3)showed a tolerable impurity concentration with the dielectric constant of ∼16 and breakdown field of∼4 MV/cm, which are approximately two-thirds of those of HfO2film grown at 250◦C