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Understanding of Thin Film Transistor Electrical Measurements in the Light of the Defect Pool Model

Published online by Cambridge University Press:  16 February 2011

S.C. Deane  and
M.J. Powell
S.C. Deane
Affiliation:
Philips Research Laboratories, Redhill, Surrey, RH1 5HA, U.K.
M.J. Powell
Affiliation:
Philips Research Laboratories, Redhill, Surrey, RH1 5HA, U.K.
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Abstract

Recently we described a new computer program which used a defect pool model of the density of states in a thin film transistor. With this model we modelled the effects of thermal bias annealing on the field effect characteristics of amorphous silicon thin film transistors, and used these results to determine key defect pool parameters. Here we use this program to provide new insight into other features of thin film transistor properties, such as activation energies of conduction as a function of gate bias, details of the subthreshold slopes, Movement of the apparent flat band voltages, and contact effects including current crowding. These effects are all successfully modelled and explained with our first principles defect pool Model, and compared with experimental results on a variety of material systems. In particular we show how measurements of the apparent flat band voltage produce potentially misleading results, and explain the inconsistency between observations of much less current crowding in contacts compared to predictions based on observed bulk defect densities and conventional Models.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 336: Symposium A – Amorphous Silicon Technology - 1994 , 1994 , 757
Copyright
Copyright © Materials Research Society 1994

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References

REFERENCES

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