Experimental evaluation of usable specimen thickness of Si for lattice imaging by transmission electron microscopy at 300 kV.

• Usable specimen thickness of Si for lattice imaging on a TEM was evaluated. • The originally developed RM was used for this evaluation. • Lattice images are successfully observed for pattern with thickness of up to 508 nm. • However, the contrast of the lattice images at a thickness of 508 nm is not distinct. • The practical thickness for analysis is less than approximately 500 nm. We evaluated the usable specimen thickness of Si for lattice imaging on a transmission electron microscopy (TEM) instrument operating at 300 kV and equipped with a complementary metal-oxide-semiconductor camera by using an original reference material (RM) and comparing the lattice images obtained from Si patterns of the RM with various thicknesses. Lattice images of the {111} planes of crystalline Si are successfully observed for patterns with thicknesses of up to 508 nm. However, the contrast of these lattice fringes at a thickness of 508 nm is not distinct, even when recorded using a longer exposure time (5.0 s) than that required to obtain lattice images of patterns with thicknesses of 316 nm or less (0.5 s). Based on these results, we conclude that the practical thickness of crystalline Si specimens for accurate structural analysis and TEM magnification calibration via lattice imaging is less than approximately 500 nm under the experimental conditions. [ABSTRACT FROM AUTHOR]