Metal precursor effects on deposition and interfacial characteristics of HfO2 dielectrics grown by atomic layer deposition

Abstract

The effects of metal precursors on deposition behavior and film properties of HfO2 were investigated and compared to replace the SiO2 gate oxide. HfO2 films were atomic layer deposited with two types of metal precursors: HfCl4 and TEMAH. TEMAH-processed HfO2 film shows a higher growth rate than HfCl4-processed film due to the higher density of hydroxyl groups on the substrate and no formation of corrosive by-products. The deposition with TEMAH results in a thinner and smoother interfacial layer between HfO2 and the substrate. This thin interface also exhibits less interfacial trap generation under constant electrical current stress.