Mapping Chemical Bonds in Semiconductor Devices by Monitoring the Shifts of EELS Edges. (29th August 2017)

• Record Type: Journal Article
• Authors: Potapov, Pavel; Svistunova, Elena L.; Gulyaev, Alexander A.
• Is Part Of: Microscopy and microanalysis. Volume 23:Number 5(2017)
• Page Start: 926
• Page End: 931
• Publication Date: 2017-08-29
• Subjects: spectrum-imaging, -- EELS, -- STEM, -- chemical shift, -- bonding; Microscopy -- Periodicals; Microchemistry -- Periodicals; 502.82
• DOI: 10.1017/S1431927617012508
• Languages: English
• ISSNs: 1431-9276

Abstract

Abstract: Scanning transmission electron microscopy (STEM) in combination with electron energy-loss spectroscopy (EELS) can deliver information about variations of bonding at the nm scale. This is typically performed by analyzing the electron-loss near edge structure (ELNES) of given EELS edges. The present paper demonstrates an alternative way of a bonding examination through monitoring the EELS onset positions. Two conditions are essential for their accurate measurement. One (hardware) is using the dual EELS instrumentation that provides near simultaneous acquisition of low-loss and core-loss spectra. Another (software) is the least-square fitting of observed spectra to a reference spectrum. The combination of these hardware and software techniques reveals the positions of EELS onsets with the precision sufficient for mapping tiny variations of bonding. The paper shows that the method is capable of helping to solve practical tasks of nanoscale engineering like the analysis of modern CMOS devices.