LAUSR

Advanced integrated circuits (ICs) are complex due to the fin field effect transistors (FinFETs), which comprise multigate transistors with the source/drain (S/D) channels (fins) surrounded by a threedimensional gate. State-of-the-art ICs are at the 10 nm and 7 nm nodes, with the later at the ramping stage of production[1]. At the 10 nm node, the S/D fins are 25% taller and 25% more closely spaced than 14 nm node technology [2]. Transmission electron microscopy (TEM) is a critical characterization tool for the semiconductor industry given the decreasing device size. Ga focused ion beam (FIB) is frequently used for advanced IC TEM specimen preparation due to its rapid, site-specific sample preparation capabilities. However, FIB milling typically results in specimen artifacts, such as surface amorphization and Ga implanted layers, both of which may limit analytical and high-resolution electron microscopy. Furthermore, 20 nm or less specimen thickness is required to characterize the 3D structures of the FinFET gate oxide in the TEM [3]. In this work, we present targeted, small spot (< 1μm ), low energy Ar milling for reproducible specimen preparation of advanced ICs with specimen thicknesses of less than 20 nm that removes FIB-induced artifacts.