Hybrid titanium-aluminum oxide layer as alternative high-k gate dielectric for the next generation of complementary metal-oxide-semiconductor devices -: art. no. 042904

Research is focused on finding reliable high-dielectric constant (k) oxides with high capacitance and all critical properties required for the next generation of complementary metal-oxide-semiconductor (CMOS) gates. A trade-off between dielectric constant and band-offset height is generally observed on gate oxides. Combining TiO2 and Al2O3, with the two extremes of high permittivity (k) and high band offset, we produced a TixAl1-xOy (TAO) oxide layer with k=similar to30 and low dielectric leakage for a next generation of high-k dielectric gates. We developed a low temperature oxidation process, following room temperature sputter-deposition of TiAl layers, to produce ultrathin TAO layers on Si with subatomic or no SiO2 or silicide interface formation. We demonstrated TAO layers with <0.5 nm equivalent oxide thickness on Si and thermal stability under rapid thermal annealing up to about 950 degreesC. The data presented here provide insights into fundamental physics and materials science of the TAO layer and its potential application as gate dielectric for the next generation of CMOS devices. (C) 2005 American Institute of Physics.