Study On Surface And Interfacial Characteristics Of HfO₂ High-k Gate Dielectric

The dimensions of the complementary metal-oxide-semiconductor devices are scaling down with the sustaining development of the IC technology. Dues to the large direct tunneling which induces extremely huge gate leakage and other limits while in the 45-nanometer technology, the conventional silicon oxide must be replaced by hafnium oxide, which is the most promising candidate insulator. With the adoption of the high-k dielectric materials, the Moore's Law curve can keeping on in the twenty-first century.In this dissertation, the HfO₂/SiO₂ stack structure gate dielectric films were fabricated on the p-type Si(100) substrates by the atomic layer deposition. After the preparation of the specimens, the x-ray diffraction, x-ray reflectometry, transmission electron microscopy, atomic force microscopy and x-ray photoelectron spectroscopy were utilized for determining the surface and interfacial characteristics of the novel ultra-thin gate dielectric films.The x-ray diffraction result manifests the HfO₂ film is almost ideal amorphous phase before and after the annealing process. The images from the atomic force microscopy and transmission electron microscopy indicate that the high-k films present very good uniformity and the thickness of the stack structure dielectric layers are 3.0nm and 0.8nm respectively. The curves of the x-ray photoelectron spectroscopy exhibit the adventitious impurities carbon and nitrogen were keeping out of the dielectric layers by introducing the state structure, and the nanometer-scale SiO₂ interfacial layer can suppress the formation of the hafnium silicates. All the properties show that the atomic layer deposition can deposit HfO₂/SiO₂ gate stack dielectrics with high performance. The author predicts the stack structure hafnium oxide gate dielectric will be an excellent novel configuration in the future.