In situUHVEM study of {113}-defect formation in Si nanowires

Results are presented of a study of {113}-defect formation in vertical Si nanowire n-type tunnel field effect transistors with nanowire diameters ranging from 40 to 500 nm. The nanowires are etched into an epitaxial moderately As doped n-type layer grown on a heavily As doped n(+) Si substrate. p(+) contacts on the nanowire are created by epitaxial growth of a heavily B doped layer. Using focused ion beam cutting, samples for irradiation are prepared with different thicknesses so that the nanowires are fully or partially embedded in the sample thickness. {113}-defects are created in situ by 2 MeV e-irradiation in an ultra-high voltage electron microscope between room temperature and 375 degrees C. The observations are discussed in the frame of intrinsic point defect properties, taking into account the role of dopants and capping layers. The important impact of the specimen thickness is elucidated.