CdCl₂ Treatment on Chemically Deposited CdS Active Layers in Thin Film Transistors

摘要

In this work CdS layers were deposited by an ammonia-free chemical bath deposition process onSiO2/p-Si substrates as active layers of thin film transistors (TFT). The electrical characteristics of theCdS-based TFT with different channel lengths were analyzed after thermal annealing in forming gascombined with previous immersion in CdCl2 saturated solution. The annealing temperatures were 100,200 and 300 C. To determine the effects of the CdCl2 treatment on the device electrical parameters,devices with and without previous immersion in CdCl2 were thermal annealed in forming gas andanalyzed. The results show that the thermal annealing processes at 100 and 200 C do not improve theelectrical characteristics of the devices in both conditions. The annealing at 300 C in both conditionsimproves noticeably the electrical performance of the devices attaining mobilities of the order of 52 cm /Vs, threshold voltage in the range -1.5-10 V, swing voltage in the range of 1.65-9 V and Ion/Ioff3 6 current ratio of the order 10 -10 .