Detecting Hot Electron-Induced Local Damage Using THz Near-Field Optical Microscopy

Abstract

Hot electron-induced degradation in semiconductor devices is a critical factor affecting the reliability and performance of microelectronic systems. While existing techniques provide valuable insights into post-failure analysis, directly visualizing hot electrons during device operation remains challenging yet essential for understanding hot electron-induced damage and degradation. In this work, we introduce ultrasensitive terahertz near-field optical microscopy to detect early-stage nanoscale damage in a GaAs/AlGaAs conducting channel with minimal conductance deviation (ΔR/R = 2.5%) by measuring hot electron-associated photon emission. Prolonged hot electron stress leads to the formation of surface lattice cracks that propagate along specific crystal orientations, underscoring the role of the hot electron in accelerating device degradation. Complementary Joule heat simulations show that lattice heating has a negligible effect on failure, supporting the conclusion that hot electron-induced effects dominate the degradation process. Our findings offer new insights into the mechanisms of hot electron-induced damage and demonstrate the terahertz nanoimaging technique as an effective tool for studying reliability issues in semiconductor devices, potentially aiding in the development of more resilient microelectronic systems.