Proc. SPIE. 11325, Metrology, Inspection, and Process Control for Microlithography XXXIV
KEYWORDS: Deep ultraviolet, Fin field effect transistors, Electro optical systems calibration, Calibration, Etching, Electron microscopes, Scanning electron microscopy, Transmission electron microscopy, Image quality, Precision measurement, Image filtering, Integrated circuits, Semiconducting wafers, 193nm lithography, Accuracy assessment
In the 14nm FinFET(Fin-shaped Field-Effect Transistor) node, SADP(Self-Aligned Double Patterning) technology has been introduced to produce Fin because of the exposure limit of 193nm DUV immersion lithography. As is known to all, pitch walking issue appears when the technology comes to SADP, so how to accurately measure pitch walking is particularly important. In this paper, we use CD-SEM(Critical Dimension Scanning Electron Microscope) to measure the CD(Critical Dimension) of Fin pitch inline, and evaluate different parameter settings or machine type to improve the accuracy of the measurement results. For sub-nanometer accuracy of line width measurement, TEM(Transmission Electron Microscope) image is used to calibrate the line width measurements as a kind of reference metrology.