Super-Resolution Fluorescence Imaging for Semiconductor Nanoscale Metrology and Inspection

Abstract

The increase in the number and complexity of process levels in semiconductor production has driven the need for the development of new measurement methods that can evaluate semiconductor devices at the critical dimensions of fine patterns and simultaneously inspect nanoscale contaminants or defects. However, conventional optical inspection methods often fail to resolve device patterns or defects at the level of tens of nanometers required for device development owing to their diffraction-limited resolutions. In this study, we used the stochastic optical reconstruction microscopy (STORM) technique to image semiconductor nanostructures with feature sizes as small as 30 nm and detect individual 20 nm-diameter contaminants. STORM imaging of semiconductor nanopatterns is based on the development of a selective labeling method of fluorophores for a negative silicon oxide surface using the charge interaction of positive polyethylenimine molecules. This study demonstrates the potential of STORM for nanoscale metrology and in-line defect inspection of semiconductor integrated circuits.

Development of Highly Dense Material-Specific Fluorophore Labeling Method on Silicon-Based Semiconductor Materials for Three-Dimensional Multicolor Super-Resolution Fluorescence Imaging

“…In contrast to most previous studies that have used a complicated multistep reaction for the selective binding of fluorescent dyes on silicon or silica layers, ,,, we aimed to develop a new simple method by avoiding complicated reactions and simplifying sample preparation; hence, we employed charge-based interactions for silica-specific labeling. We recently demonstrated that the charge-based interaction can be employed for the fluorophore labeling on the silicon-based material . To decorate only a line-patterned SiO 2 layer with organic fluorescence dyes using charge-based interactions, we used poly- l -lysine (PLL) and a dye-labeled bovine serum albumin (BSA) protein.…”

“…We recently demonstrated that the charge-based interaction can be employed for the fluorophore labeling on the siliconbased material. 24 To decorate only a line-patterned SiO 2 layer with organic fluorescence dyes using charge-based interactions, we used poly-L-lysine (PLL) and a dye-labeled bovine serum albumin (BSA) protein. Oxide ions at the surface of the thin SiO 2 layer may provide a layer of negative charges, whereas PLL contains a positively charged hydrophilic amino group at pH 7; hence, the positively charged PLL is expected to bind selectively to the negatively charged line-patterned oxide layer.…”

Single‐molecule fluorescence microscopy for imaging chemical reactions: Recent progress and future opportunities for advancing polymer systems

“…28 It is important to note that electrochemical and interfacial reactions of polymeric materials are important processes, which are highly relevant with various industrial and consumer products as coatings, 239,240 adhesives, 241,242 and semiconductors. [243][244][245] The understanding of chemical reactions of polymers at interfaces and in electrochemical cells continues to advance and examining these systems at the single-molecule level with fluorescence techniques furthers this understanding relevant to industry. As imaging technology becomes more available and accessible, interest and capability grow in characterizing commercially used polymer products and reactions, and further development in this area may lead to new discoveries or applications for already implemented products and technologies.…”

“…Fluorescent labeling has also been used for imaging electrochemical processes involving proteins and enzymes since the labels often do not disrupt molecular function and provide insight into the system's heterogeneity 28 . It is important to note that electrochemical and interfacial reactions of polymeric materials are important processes, which are highly relevant with various industrial and consumer products as coatings, 239,240 adhesives, 241,242 and semiconductors 243–245 . The understanding of chemical reactions of polymers at interfaces and in electrochemical cells continues to advance and examining these systems at the single‐molecule level with fluorescence techniques furthers this understanding relevant to industry.…”

Optical Far-Field Detection of Sub-λ/14 Wide Defects by Conjugate Structured Light-Field Microscopy (c-SIM)

“…As a result, the time-consuming and destructive e-beam inspection has to be used instead of optical inspection for defect classification . Optical super-resolution imaging techniques, such as stimulated emission depletion microscopy − and photothermal nonlinear confocal microscopy, have the capability of imaging deep subwavelength nanostructures, but they require either fluorescence labeling or sample heating, which may pollute or damage the patterned wafer to some extent. Therefore, an optical far-field imaging method can not only inspect killer defects on the patterned wafer but also classify various types of defects in a fast, nondestructive, easy-of-operate, and large-FOV manner, which is of great importance to the field.…”