Influence of photoperturbation on the characterization accuracy of scanning capacitance microscopy MOSFET example

摘要

Due to the photoperturbation induced by the atomic force microscopy laser beam, typical scanning capacitance microscopy (SCM) may produce false differential capacitance images of carrier distribution and electrical junctions. For a real MOS device, the photoperturbation can lead to a broadened source/drain region and narrower effective channel length (L_eff). The photoperturbation also leads to many difficulties in employing SCM to investigate the influence of annealing processes on electrical junctions. It is revealed that the photoperturbation-induced errors in the measurements of L_eff and electrical junction width may be up to 11.2% and 50%, respectively.