Interface coupling and film thickness measurement on thin oxide thin film fully depleted SOI MOSFETs

Abstract

We report here the results of film thickness measurements of thin film fully-depleted (FD) SOI MOSFETs, using the interface coupling dependence of the threshold voltage. We have investigated in particular the validity of the extraction method for ultrathin gate oxide and thin film devices. We found a discrepancy between the extracted electrical value and the physical one measured by TEM. We show that the extraction of the correct film thickness requires the determination of-the physical oxide thickness. We have also compared the results obtained for neighbouring PMOS and NMOS.