具奈米級氧化層金氧半(MOS)結構的光電特性

Silicon dioxide films were prepared on n-type silicon surfaces using spin-coating method. Field-emission scanning electron microscope (FE-SEM) images, it shows the spin-oxide grain size ranging with 50 to 60 nm and X-Ray Diffractometer (XRD) shows that structure of the silicon dioxide films are polysilicon. Al/nano-SiO2/n-Si/Al MOS capacitors were prepared to determine current-voltage (I-V) and capacitance-voltage (C-V). In our experiments, a low leakage current density of 4.3×10^(-10)A/cm^2 under a 5MV/cm electric field was observed. C-V measurement of MOS capacitors was employed at high-frequency of 1 MHz. Moreover, compared to the as prepared and the N2-annealed samples at 500℃ for 30 min. Their fixed oxide charge density is reduced from 3.9×10^12cm^(-2) to 9×10^11 cm^(-2) and the flatband voltage shift ΔV(subscript FB) can be reduced from -2V to -0.6V. The ratio of photo to dark current was 9.1 for the wavelength of 850 nm.