Secondary-Electron-Energy-Spectroscopy (SEES) for Semiconductor Surface Defect Characterization

we utilize a Scanning Auger Microscope (SAM) equipped with a Cylindrical Mirror Analyzer (CMA) conventionally used for Auger spectroscopy. The SAM setup was modified to spectroscopically resolve secondary electrons, overcoming the technical hurdle of their inherently low kinetic energies. In parallel, we integrate a custom-built electron energy analyzer directly into a commercial SEM [3]. Together, these efforts establish a robust, cross-validated methodology for SEES-based semiconductor defect analysis. As testbed, we investigate epitaxial Ge-on-Si heterostructures, where a lattice mismatch <5% generates misfit dislocations acting as sources of threading dislocations, which propagate through the germanium layer. These threading dislocations are usually a undesired guest in the electronic industry, as they degrade the device performance by acting as scattering and non-radiative recombination centers. Using a correlative microscopy workflow, we first map the spatial distribution of these dislocations via custom EBIC and ECCI setups. Subsequent SEES analysis using the SAM-CMA reveals a distinct contrast in the secondary electron emission spectra between dislocated and defect-free Ge layers, confirming that dislocations measurably alter SE emission dynamics. Correlating SEES with EBIC and ECCI on a Ge-on-Si heterostructure demonstrates that semiconductor defects yield a distinct, measurable contrast in secondary electron emission spectra. Future work will aim at unravelling the physical mechanisms driving these localized emission dynamics and advance toward 2D SE energy-based defect mapping. Ultimately, we aim to establish SEES as a non-destructive, surface sensitive, high-resolution metrology tool for semiconductor characterization. This work is funded by the European Union – NextGenerationEU – Project Number 2022LA3TJ8 – CUP D53D23002280006, Project P2022YM8J3 – CUP D53D23018720001, Project PE0000021 - CUP D43C22003090001 [1] H. J. Leamy, "Charge collection scanning electron microscopy," J. Appl. Phys. 53, R51 (1982). [2] S. Zaefferer and N.-N. Elhami, "Theory and application of electron channelling contrast imaging under controlled diffraction conditions," Acta Mater. 75, 20-50 (2014). [3] W. Han, M. Zheng, A. Banerjee, Y. Z. Luo, L. Shen, and A. Khursheed, "Quantitative material analysis using secondary electron energy spectromicroscopy," Sci. Rep. 10, 22144 (2020).