Plasma-enhanced atomic layer deposition of WO3-SiO2 films using a heteronuclear precursor

Tungsten oxide–silicon dioxide (WOx–SiOy) composite thin films were deposited for the first time via remote oxygen plasma-enhanced atomic layer deposition (ALD) process using a novel metal-organic heteronuclear and heteroleptic precursor, bis(tert-butylimido)bis(trimethylsilylmethyl)tungsten. Self-limiting ALD growth was demonstrated over wide temperature window of 203–328 °C with per cycle decreasing increasing from 0.75 to 0.4 Å/cycle, respectively. Residual gas analysis revealed ligand competition showed that reaction during nucleation function temperature, thereby affecting film composition. As increased 203 328 °C, composition [W/(Si + W)] ranged 0.45 0.53. In addition, carbon impurity content reduced refractive index 1.73 1.96, density 4.63 5.6 g/cm3, optical bandgap decreased 3.45 3.27 eV. Grazing angle x-ray diffraction indicated as-deposited amorphous. Upon annealing in O2 at 500 or higher, depending on are crystalized into triclinic WO3 phase. At same time, is sublimed surface thickness.