Electrical Characteristics Analysis at "Oxide Flat-Band Voltage" for Al-SiO2-Si Capacitor

Abstract

In this paper, a new noun named "oxide flat-band voltage" is proposed meaningfully and further electrical characteristics study focused on non-uniformity in MOS capacitor will be demonstrated. Based on the rectangular barrier approximation, the slope of the ln[Jg@Vox,fb] versus oxide thickness plot of -12.18 is much closer to the theoretical slope of -12.42 than the slope of the ln[Jg@Vfb] versus oxide thickness plot of -11.09. It is because that there are some negative charges existing in the SiO2 dielectrics during the film-grown anodization system resulting in the non-uniformity phenomenon. Furthermore, various device areas of MOS capacitor were designed to do an advanced non-uniformity study. Both in the analysis of differential J-V curves and the slope of natural log of gate current density versus oxide thickness plot, it indicates evidently and identically that the larger the gate electrode area, the worse uniform the dielectric is.