Investigation of drain current transient behavior in SLS TFTs with the DLTS technique

In this work, the study of drain current overshoot transients of thin film transistors (TFTs) fabricated by excimer laser sequential lateral solidification (ELA SLS) process is presented. Drain current transient behavior, is ascribed to carrier capture/emission processes within the transistors' Si body, and represents complex mechanisms differently responding at dark and under illumination conditions. Additionally, the thickness of the Si body film, which is an important parameter for the material structure evaluation, ranged from 30 nm to 100 nm. The results were stemmed by deep level transient spectroscopy (DLTS) technique and measurements were conducted within the temperature interval of 200 K to 400 K. The impact of illumination, contributes mainly at lower temperatures through electron-hole generation processes, compensating though carrier freeze-out phenomena.