Electron-beam-induced-current (EBIC) microscopy has the unique capability of simultaneously providing structural and transport characteristics of semiconductors. However, EBIC is traditionally performed inside an SEM with less than 40 keV electron beam energy. As the result, the applications of traditional EBIC for semiconductor device characterization are limited by either probing depth (0.02 ~0.05 μm with 2 ~5 keV electron beams) or spatial resolution (1-2 um with 20 ~40 keV electron beams). To achieve useful resolution for studying the interface effects critical to today's submicron devices, one would have to prepare the samples by either removing the passivation/metallization layers or making cross sections. In this paper, we report a breakthrough in the art of EBIC using high-voltage electron beams (200 keV and higher) to improve the spatial resolution and probing depth simultaneously. Adopting a JEOL 4000FX AEM for EBIC imaging, a spatial resolution of 0.05 um was demonstrated from structures 0.5 um beneath the surface. Using this technique, we have identified a facet degradation mechanism in strained quantum well laser diodes and hot-electroninduced defects in GaAs metal-semiconductor field-effect transistors (MESFETs).
Recent Advances in High Voltage Electron Beam Injectors
