The Study of Electrical Properties for Multilayer La2O3/Al2O3 Dielectric Stacks and LaAlO3 Dielectric Film Deposited by ALD

Abstract

The capacitance and leakage current properties of multilayer La2O3/Al2O3 dielectric stacks and LaAlO3 dielectric film are investigated in this paper. A clear promotion of capacitance properties is observed for multilayer La2O3/Al2O3 stacks after post-deposition annealing (PDA) at 800 °C compared with PDA at 600 °C, which indicated the recombination of defects and dangling bonds performs better at the high-k/Si substrate interface for a higher annealing temperature. For LaAlO3 dielectric film, compared with multilayer La2O3/Al2O3 dielectric stacks, a clear promotion of trapped charges density (Not) and a degradation of interface trap density (Dit) can be obtained simultaneously. In addition, a significant improvement about leakage current property is observed for LaAlO3 dielectric film compared with multilayer La2O3/Al2O3 stacks at the same annealing condition. We also noticed that a better breakdown behavior for multilayer La2O3/Al2O3 stack is achieved after annealing at a higher temperature for its less defects.