Direct Atomic Scale Characterization of Interfaces and Doping Layers in Field-Effect Transistors.

Abstract

Abstract The demand for the higher performance of semiconductor devices, for instance IC functionality, has stimulated industry to further scale the critical dimensions of the semiconductor devices [6]. Also, as parasitic capacitances are reduced in small device structures, the energy loss in these devices is consequently reduced. [1] Achieving the desired performance from such reduced device structures requires optimization of both the interface properties and dopant redistribution processes, such as diffusion and segregation, under various processing conditions. Only through a careful and accurate characterization of these properties on the atomic scale in the electron microscope we can achieve the understanding of the materials interactions during processing necessary to optimize these properties [2]. Conventional imaging and microanalysis techniques in transmission electron microscopy (TEM), such as phase contrast imaging and energy dispersive X-ray spectroscopy (EDS), lack either the spatial resolution or require extensive simulations and through focal series reconstructions to reveal the structure and composition of such interfaces/doping layers (and in the case of simulations may still not give a unique solution).