Surface and defect analysis in advanced materials: leveraging EBIC and SEES in SEM

Defects in semiconductors hinder charge flow, leading to higher energy loss and reduced efficiency, limiting device functionality. Therefore, this resulted in raised rationale behind their thorough investigation. Electron Microscopy (EM) is a prevalent nanomaterials characterisation and imaging technology. EM characterisation techniques such as Transmission Electron Microscopy (TEM), Electron Beam Induced Current (EBIC), Cathodoluminescence (CL), and optical techniques such as Photoluminescence, provide a wealth of information in mapping defects in semiconductors and studying their electrical attributes. These techniques offer bulk information, either destructive or not spatially resolved. The surface of semiconductors plays a vital role in their functionality, so a technique offering a non-destructive nature, spatially resolved (nm), and providing surface-sensitive defect information is crucial. Secondary Electrons (SE) offer thorough insights into local work function, bulk density of states (DOS), and surface potential of material with nanoscale resolution and potentially Secondary Electron Energy Spectroscopy (SEES) could deliver insight for analysing defects on the surface. We adopted our SEM for Secondary Electron Energy Spectroscopy (SEES) with a toroidal electron energy analyzer and establishing EBIC characterization using a fast trans-impedance amplifier. SEES developments delivered DOS information and working on EBIC experimentation utilising Ge-Si heterostructure. Integrating SEES and EBIC could potentially provide comprehensive defect analysis at different depth scales.