OH dangling-bond saturation and dielectric function effects in ultra-scaled SNW-FETs

State-of-the-art analyses of the electronic properties of silicon nanowires (SNWs) are usually based on H-saturated interface bonds . However, only a minority of dangling bonds are saturated by H at the typical Si-SiO₂ interface. Moreover, the variations of the dielectric function with the lateral size of the SNW have not been addressed. In this work, we investigate the electronic properties and I-V characteristics of a 7times7 SNW with OH-saturated dangling-bonds and of a 5times5 SNW accounting for the variation of the dielectric function. To this purpose, we use a new approach to the computation of quantum transport which accounts for the complete periodic shape of the IDEG energy subbands for the ID transport . The main findings of our analysis are: i) the band structures of SNW with dangling-bonds saturated with H or OH show relevant differences in the shape and energy of the subbands, leading to different transport characteristics; ii) the calculated dielectric function in the 5times5 SNW is about 50% smaller with respect to bulk, which leads to a 20% reduction of the ON-current.