The effects and mechanisms responsible for charge lateral migration in 3D SONOS devices are studied in detail. We evaluated the electron lateral migration at room temperature and at 150 degrees C in 3D SONOS devices. Through interpretation of measurements and simulations, we found that lateral migration shows similar emission rates of Poole-Frenkel effect and therefore it is linked to the same trap energy profile. This feature should be included in a model to properly simulate 3D SONOS retention transients. Further experiments and simulations show no influence of SiN thickness nor P/E cycles on lateral migration. (C) 2015 Elsevier Ltd. All rights reserved.