Thin films of metal oxides on silicon by chemical vapor deposition with organometallic compounds. I

Thin films of TiO₂, ZrO₂ and HfO₂ have been deposited on single crystals of (111) silicon, by chemical vapor deposition (CVD) of the respective organometallic compounds. The thin films of TiO₂ have the anatase structure while ZrO₂ and HfO₂ are monoclinic. All films are easily etched by 5% HF solution, while films of TiO₂ are also etched by 70% H₂SO₄. The indices of refraction of the thin films are 2.05-2.26 for TiO₂, 1.94 for ZrO₂ and 2.02 for HfO₂. All the oxide films show good MOS C-V characteristics, the flatband voltages having values near zero. The bias-temperature (B-T) tests on C-V curves in the case of HfO₂ show high stability.