Fabrication of Y doped HfO2 epitaxial films directly on (001) si substrate

Abstract

Discovery of ferroelectric behavior of HfO2-based thin film is attracting much attention as a material applicable to FeFET based on the non-destructive operation with low power consumption and which obeys the scaling rule. For application to FeFET it is an important to grow orthorhombic HfO2 directly on Si substrate without buffer layer. In this paper, the crystal structure and the growth process of HfO2:Y epitaxial films on (001) Si substrate by pulsed laser deposition method are discussed. The effect of the O2 gas pressure and laser power for ablation on the crystal structure, the lattice parameters and the growth process are studied. It is revealed that the epitaxial HfO2:Y films can be obtained by controlling the oxygen pressure before deposition and active O* species in plume during deposition.