Abstract
Bias stress measurements on amorphous silicon - silicon nitride ambipolar thim film transistors (TFTs) give clear evidence for the coexistence of two mechanisms responsible for the threshold voltage shift; the metastable creation of fast states and charge trapping in slow states. State creation dominates at low positive bias and charge trapping at higher bias. Measurements on a series of standard TFTs, where the composition of the nitride is varied, show the state creation to be independent of nitride composition, whereas the charge trapping depends strongly on the nitride composition. We conclude that the slow states are located in the nitride, whereasthe metastable states are confined to the a-Si:H layer. The metastable states are suggested to be Si dangling bonds in a-Si:H, created by populating the antibonding orbitals of weak Si-Si bonds. The slow states are also thought to be Si dangling bonds, but located in the nitride. We proposed that charge transfer into these latter states is by hopping.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.