Structural and electrical characteristics of thin erbium oxide gate dielectrics

摘要

A high-k erbium oxide thin film was grown on silicon substrate by reactive rf sputtering. It is found that the capacitance value of Er_2O_3 gate dielectric with TaN metal gate annealed at 700℃ is higher compared to other annealing temperature and exhibits a lower hysteresis voltage as well as interface trap density in C-V curves. They also show negligible charge trapping under high constant voltage stress. This phenomenon is attributed to a rather well-crystallized Er_2O_3 and the decrease of the interfacial layer and Er silicate thickness observed by x-ray diffraction and x-ray photoelectron spectroscopy, respectively.