Bias dependence of instability mechanisms in amorphous silicon thin-film transistors
- 19 October 1987
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 51 (16) , 1242-1244
- https://doi.org/10.1063/1.98692
Abstract
We have measured the bias dependence of the threshold voltage shift in a series of amorphous silicon-silicon nitride thin-film transistors, where the composition of the nitride is varied. There are two distinct instability mechanisms: a slow increase in the density of metastable fast states and charge trapping in slow states. State creation dominates at low fields and charge trapping dominates at higher fields. The state creation is found to be independent of the nitride composition, whereas the charge trapping depends strongly on the nitride composition. This is taken as good evidence that state creation takes place in the hydrogenated amorphous silicon (a-Si:H) layer, whereas the charge trapping takes place in the a-SiN:H. The metastable states are suggested to be Si dangling bonds in the a-Si:H, and the state creation process similar to the Staebler–Wronski effect. The confirmation of state creation in a thin-film transistor means that states can be created simply by populating conduction-band states in the undoped material. The slow states are also thought to be Si dangling bonds, but located in the silicon nitride matrix.Keywords
This publication has 14 references indexed in Scilit:
- Resolution of amorphous silicon thin-film transistor instability mechanisms using ambipolar transistorsApplied Physics Letters, 1987
- Fast and slow states at the interface of amorphous silicon and silicon nitrideApplied Physics Letters, 1986
- Metastable Defects in Amorphous-Silicon Thin-Film TransistorsPhysical Review Letters, 1986
- Localized states in doped amorphous siliconJournal of Non-Crystalline Solids, 1985
- Material Properties Controlling the Performance of Amorphous Silicon Thin Film TransistorsMRS Proceedings, 1984
- Influence of excess carriers on the Staebler and Wronski effect of a-Si solar cellsJournal of Non-Crystalline Solids, 1983
- Charge trapping instabilities in amorphous silicon-silicon nitride thin-film transistorsApplied Physics Letters, 1983
- Annealing and light induced changes in the field effect conductance of amorphous siliconJournal of Applied Physics, 1982
- Light-induced dangling bonds in hydrogenated amorphous siliconApplied Physics Letters, 1981
- Optically induced conductivity changes in discharge-produced hydrogenated amorphous siliconJournal of Applied Physics, 1980