Mapping Conductivity and Electric Field in an AlGaAs HEMT with STEM EBIC

Abstract

Abstract The operation of modern semiconductor components often relies on nanoscale electronic features emerging from complicated device architectures with finely tuned composition. While the physical structure of these devices may be straightforward to image, the resulting electronic characteristics are invisible to most high-resolution imaging techniques. Here we present electron beam-induced (EBIC) imaging in the scanning transmission electron microscope (STEM) as a high-resolution imaging technique with electronic-based contrast for characterizing complex semiconductor devices. Here, as an example case, we discuss the preparation and imaging of a STEM EBIC-compatible cross section extracted from a commercial AlGaAs high electron-mobility transistor (HEMT). The device exhibits low surface leakage, as measured via electrical testing and STEM EBIC conductivity contrast. The EBIC signal in the active layer of the device is mostly confined to the InGaAs channel, indicating that the electronic structure is largely preserved following sample preparation.