CHARACTERIZATION OF SILICON SURFACE MICROROUGHNESS AND TUNNELING TRANSPORT THROUGH ULTRATHIN GATE OXIDE

The surface morphology of chemically cleaned Si(100) surfaces has been studied by Fourier-transform infrared-attenuated total reflection (ATR) and atomic force microscopy (AFM). It is shown that the final cleaning in 0.1%HF+1%H2O2 after modified SC-1 clean yields a sharp SiH2 vibrational peak with weak SiH3 and SiH absorption bands while 4.5%HF treatment gives the twin peaks consisting of SiH2 and SiH3 absorptions. In contrast to this the AFM images exhibit no significant changes for the surfaces with significantly different ATR spectra. Quantitative analysis of the measured tunneling current for metal-oxide-semiconductor diodes fabricated on (100) surfaces with different surface morphologies has shown that the observed current is well fitted to the theoretically predicted characteristics.