Monte Carlo Simulation Study: the effects of double-patterning versus single-patterning on the line-edge-roughness (LER) in FDSOI Tri-gate MOSFETs

Abstract

A Monte Carlo (MC) simulation study has been done in order to investigate the effects of line- edge-roughness (LER) induced by either 1P1E (single-patterning and single-etching) or 2P2E (double-patterning and double-etching) on fully- depleted silicon-on-insulator (FDSOI) tri-gate metal- oxide-semiconductor field-effect transistors (MOSFETs). Three parameters for characterizing the LER profile (i.e., root-mean square deviation (σ), correlation length (ζ), and fractal dimension (D)) are extracted from the image-processed scanning electron microscopy (SEM) image for each photolithography method. It is experimentally verified that two parameters (i.e., σ and D) are almost the same in each case, but the correlation length in the 2P2E case is longer than that in the 1P1E case. The 2P2E-LER- induced VTH variation in FDSOI tri-gate MOSFETs is smaller than the 1P1E-LER-induced VTH variation. The total random variation in VTH, however, is very dependent on the other major random variation sources, such as random dopant fluctuation (RDF) and work-function variation (WFV).