Uncertainty evaluation of Monte Carlo simulated line scan profiles of a critical dimension scanning electron microscope (CD-SEM)

Abstract

In recent years, precision and accuracy for a more precise critical dimension (CD) control have been required in CD measurement technology. CD distortion between the measurement by a critical dimension scanning electron microscope (CD-SEM) and a reference tool is the most important factor for a more accurate CD measurement. CD bias varies by a CD-SEM and a pattern condition. Therefore, it is urgently needed to identify, characterize, and quantify those parameters that may or may not affect the CD measurement by a CD-SEM. The sensitivity of the Monte Carlo simulated CD-SEM images with multiple physical modeling components has been studied previously. In this study, we demonstrate that the work function and elastic scattering potential models have a significant impact on secondary electron emission intensity, but their influence on the shape of the linescan profile is small, and other factors like the optical energy loss function and dielectric function models have even smaller effects. We have evaluated the uncertainty in the linescan profiles of Si line structures with different sidewall angles due to several different physical factors. It is found that when the CD is evaluated by a peak/valley method, the uncertainty of the CD is negligible. Therefore, it is concluded that the CD value and its related uncertainty are not critically related to the physical factors of the present Monte Carlo simulation model but rely dominantly on the line structure and electron beam parameters.

Magnetic hysteresis mechanism in Lu0.9Sr0.1Cr0.5Fe0.5O3 studied by Monte Carlo simulations

“…Finally, since our intention is to describe the hysteresis properties of Lu 1−x Sr x Cr 0.5 Fe 0.5 O 3 (x = 0 and 0.1) compounds with a qualitatively model with physical meaning parameters, we will not perform an uncertainty analysis, which is a common practice in MC modeling, see e.g. [27].…”

Application of a machine learning method to model-based library approach for critical dimension measurements using CD-SEM

“…Villarrubia et al [34] confirmed that the MBL method can be applied to linewidth measurements down to 10 nm scale; the measurements were in good agreement with the direct observation by a transmission electron microscope. Khan et al [35] investigated the influence of the Monte Carlo model parameters on the CD determination and related theoretical uncertainties in the MBL method.…”

Linewidth characterization of a self-traceable grating by SEM

“…Zou et al further investigated Si nanowires with smaller linewidth scales, considering the influence of an Au substrate and electron beam parameters [43]. Khan et al studied the uncertainty of the linescan profile shapes due to physical models and electron beam parameters [44]. An ISO standard for the evaluation of linewidth by SEM has been recently established for the trapezoidal line structure in semiconductor devices [45].…”