Characterization of La[sub 2]O[sub 3] and Yb[sub 2]O[sub 3] Thin Films for High-k Gate Insulator Application

Rare earth oxides, such as and deposited on Si(100) were investigated for high- k gate insulator applications. has the largest bandgap and smallest lattice energy among the rare earth oxides, while has a smaller bandgap and larger lattice energy compared to showed excellent electrical properties, such as small capacitance equivalent thickness and low leakage current density with smooth film surface and interface after rapid thermal annealing (RTA) at 400-600°C. On the other hand, the surface of thin film was easily roughened after RTA even at 400°C, and the leakage current density was higher compared to The difference in characteristics for the films was considered to be attributed to the difference of their properties, such as bandgap and lattice energy. was able to keep the amorphous phase at least up to 600°C RTA, and this seems promising for future high- k gate insulator applications. © 2003 The Electrochemical Society. All rights reserved.