Growth and Characterization of Ti-Ta-O Thin Films on Si Substrates by Liquid Injection MOCVD for High-k Applications from Modified Titanium and Tantalum Precursors

Titanium oxide (TiO2) and titanium-tantalum oxide (Ti-Ta-O) thin films are deposited by liquid injection (LI) metal-organic (MO) CVD using metal amide-malonate complexes, [Ti(NR2)2(dbml)2], and tantalum, [Ta(NMe2)4(dbml)] (R = Me, Et; dbml = di-tert-butylmalonato). TiO2 and Ti-Ta-O films are deposited on Si(100) in the temperature ranges 350-–650 °C and 500–700 °C, respectively. The structure, morphology, and chemical composition of the films are evaluated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), Rutherford backscattering spectroscopy (RBS), and X-ray photoelectron spectroscopy (XPS). The electrical properties of the films, namely the dielectric properties, are assessed by carrying out capacitance-voltage (C-V) measurements on metal-oxide-semiconductor (MOS) capacitor structures.