High-quality nano spin-oxide for possible applications in metal??oxide semiconductor field-effect transistor

Nano silicon dioxide (SiO₂) has been deposited on silicon substrate using spin-coating method and Al/nano-SiO₂/n-Si metal-oxide semiconductor (MOS) capacitors have been fabricated to characterise their electrical properties using current-voltage (I-V) and capacitance-voltage (C-V) measurements. Field-emission scanning electron microscope shows the spin-oxide with grain size ranging 50-60-nm. For as-formed spin-oxide, a large leakage current density of 5.14 × 10^-5 cm^-2 under 5 MV/cm field and fixed oxide charge density of 3.9 × 10¹² cm^-2 are obtained. After annealing at 500°C in N₂ environment for 30 min, the leakage current and fixed oxide charge density are drastically reduced to 4.3 × 10^-10 A/cm² and 9 × 10¹¹ cm^-2, respectively. Such a large improvement, by five orders, in leakage current density demonstrates that the prepared nano spin-oxide exhibits a potential application in fabricating high-quality MOS field-effect transistor.