Deposition of HfO 2 Films by Liquid Injection MOCVD Using a New Monomeric Alkoxide Precursor, [Hf(dmop) 4 ]

Thin films of HfO 2 have been deposited by liquid injection metal‐organic (MO)CVD using the new alkoxide precursor [Hf(dmop) 4 ] (dmop = 2‐(4,4‐dimethyloxazolinyl)‐propanolate). The crystal structure of [Hf(dmop) 4 ] has been determined, and shows it to be a six‐coordinate monomeric complex. [Hf(dmop) 4 ] is volatile and is significantly less reactive to air and moisture than simple Hf alkoxide complexes such as [Hf(O t Bu) 4 ]. The HfO 2 thin films were deposited over substrate temperatures ranging from 350 °C to 650 °C. Analysis by X‐ray diffraction (XRD) shows that the films are amorphous at deposition temperatures of 400 °C and below. At substrate temperatures above 450 °C, the films adopt a monoclinic (α‐HfO 2 ) phase with a fiber texture dependent upon growth temperature. Analysis by Auger electron spectroscopy (AES) shows that the films are non‐stoichiometric and contain residual carbon (2.1 – 11.6 at.‐%) and nitrogen (0.4 – 1.9 at.‐%). Thin films of HfO 2 have important potential applications in microelectronics. This paper describes the growth of these oxides by liquid injection MOCVD using a new class of alkoxide precursor [Hf‐(dmop) 4 ]. The Figure shows the crystal structure of [Hf(dmop) 4 ]. Films were deposited over substrate temperatures ranging from 350 °C to 650 °C, and analysis by XRD shows that films are amorphous at deposition temperatures below 400 °C and adopt a monoclinic (α‐HfO 2 ) phase with a fiber texture dependent upon growth temperature at substrate temperatures above 450 °C.