Tomographic analysis of a FinFET structure

Abstract

In order to meet the International Technological Roadmap for Semiconductor (ITRS) goals [1] for the 32nm node and beyond new structures as the multiple-gate Silicon on insulator MOSFET (Metal Oxide Semiconductor Field Effect Transistor) with good short channel characteristics and high drive current are introduced [2]. One of the considered configurations is the FinFET (Fin Field Effect Transistor) structure consisting of single crystalline silicon fins with the gate line crossing in the orthogonal direction (Figure 1). Because the typical dimensions of these structures are smaller than the thickness of the TEM specimen, the overlap of different materials along the electron beam direction renders the interpretation of the conventional TEM images (Figure 2) difficult. Tomographic 3D reconstruction from high angular annular dark field scanning (HAADFS) TEM image series can overcome this problem, and is therefore likely the most suited technique in order to characterize such devices.