Effect of amorphous silicon material properties on the stability of thin film transistors: evidence for a local defect creation model

We present an improved description of the defect creation kinetics in amorp hous silicon thin film transistors and analyze in detail the dependence on the key amorphous silicon material properties: Urbach energy, hydrogen cont ent, hydrogen bonding and intrinsic stress. The results support a model for defect creation, involving Si-Si bond breaking, with only local hydrogen b onding rearrangements to stabilize the broken bond, as opposed to models in volving long range hydrogen diffusion. On the other hand, defect annealing proceeds by breaking Si-H bonds and long-range diffusion of hydrogen. (C) 2 000 Elsevier Science B.V. All rights reserved.