Thin films of HfO₂ for high- k gate oxide applications from engineered alkoxide- and amide-based MOCVD precursors

HfO2 thin films with thickness between 2 and 20 nm were grown by liquid injection metallorganic chemical vapor deposition, LI-MOCVD, on SiOx Si(100) substrates. Different mononuclear precursors ([Hf (OPri) 2 (tbaoac) 2], [Hf (NEt2) 2 (guanid) 2], and [Hf (OBut) 2 (dmae) 2] were tested in combination with different solvents. Growth rate, surface morphology, crystal structure, and crystal density of the as-deposited films were analyzed as a function of deposition temperature. The influence of postdeposition annealing on the densification and crystallization was studied. Correlation of the structural properties with the electrical properties of metal insulator semiconductor capacitors with Pt top electrodes is discussed. Fully silicided metal gate stacks are additionally discussed for selected samples.