Surface reaction of the hafnium precursor with a linked amido-cyclopentadienyl ligand: A density functional theory study

We studied heteroleptic Hf precursors with a linked amido-cyclopentadienyl ligand by density functional theory (DFT) calculation to enable high-temperature atomic layer deposition processes. The thermolysis and hydrolysis of Hf precursors were simulated to expect thermal stability and reactivity with hydroxyl groups. The effects of alkyl groups in the precursors were also investigated. We constructed the hydroxylated HfO2 surface and then simulated the surface reactions of the precursors. The precursors with the linked ligand showed higher activation energies for thermolysis and lower activation energies for hydrolysis as compared with CpHf(NMe2)3. The precursors with the linked ligand also showed low activation energies for the serial ligand exchange reactions on the HfO2 surface, significantly lower than those of CpHf(NMe2)3. Therefore, the DFT calculation suggests that the Hf precursors with the linked ligand are promising due to their thermal stability and reactivity better than CpHf(NMe2)3.