Investigation On Characteristics Of Atomic Layer Deposited Titanium Dioxide Stack Gate Structure Dielectric

The dimensions of the complementary metal-oxide semiconductor devices are scalingdown with the sustaining development of the IC technology, which results in the increasingof the gate leakage current and the decreasing of the gate dielectric reliability of traditionalSiO2dielectric. The conventional silicon oxide must be replaced by high-k material.In this dissertation，theTiO2/Si3N4stack structure gate dielectric films were fabricatedon the p-type Si(111) substrates by the atomic layer deposition．After the preparation ofthe specimens, transmission electron microscopy, atomic force microscopy and x-rayphotoelectron spectroscopy were utilized for determining the surface and interfacialcharacteristics of the novel ultra-thin gate dielectric films and IV characteristics．The images from the atomic force microscopy and transmission electron microscopyindicate that the high—k films present very good surface characteristics and the thicknessof the stack structure dielectric layers are6nm and0.9nm respectively．The curves of thex-ray photoelectron spectroscopy exhibit the adventitious impurities carbon and nitrogenwere keeping out of the dielectric layers by introducing the state structure，and theSi3N4nanometer-scale interfacial layer can suppress the formation of theSiO2. Through the IVcurves can indicate that the leakage current significantly improved. All the Properties showthat the atomic layer deposition can depositTiO2/Si3N4gate stack dielectrics with highperformance．The author predicts the stack structure gate dielectric will be excellent novelconfiguration in the future．...