In this thesis electron tomography is developed and applied as a tool for three-dimensional nanoscale characterization of semiconductor materials and devices. The major contributions of this thesis are the exploration and application of transmission electron microscopy (TEM) contrast techniques for specific semiconductor applications and the exploration of routes towards improving spatial resolution, in particular by adapting tomographic acquisition schemes. As contrast techniques we apply high-angle annular dark-field (HAADF) scanning TEM (STEM) for investigations of heavy dopants in a lighter environment and we combine spectral low-loss energy-filtered TEM (EFTEM) with tomography and explore the features of reconstructed low-loss spectra. For resolution improvement we experimentally apply dual-axis electron tomography and investigate the potential of multiple-axis tomography based on simulations. Furthermore reconstruction algorithms based on totalvariation minimization are applied to electron tomography. Samples investigated in this work include tri-gate transistors, III-V nanowire heterostructures and silicon nanowire based capacitors as well as selenium-hyperdoped silicon, a material for optoelectronic applications.
3D nanoimaging of semiconductor devices and materials by electron tomography