Analysis on Trapping Kinetics of Stress-Induced Trapped Holes in Gate Dielectric of Amorphous HfInZnO TFT
A comprehensive study was done regarding stability under simultaneous stress of light and negative gate dc bias in amorphous hafnium-indium-zinc-oxide (α-HIZO) thin-film transistors. A negative threshold voltage (V th ) shift and an anomalous hump were observed in transfer characteristics after the...
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Published in | IEEE transactions on electron devices Vol. 63; no. 6; pp. 2398 - 2404 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
New York
IEEE
01.06.2016
The Institute of Electrical and Electronics Engineers, Inc. (IEEE) |
Subjects | |
Online Access | Get full text |
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Summary: | A comprehensive study was done regarding stability under simultaneous stress of light and negative gate dc bias in amorphous hafnium-indium-zinc-oxide (α-HIZO) thin-film transistors. A negative threshold voltage (V th ) shift and an anomalous hump were observed in transfer characteristics after the stress, and it is explained that these phenomena are caused by the hole trapping in the SiO 2 gate insulator, not by interface state generation. Furthermore, capacitance-voltage (C G -V G ) measurements were performed with various frequencies to investigate the vertical distribution of the trapped holes in the gate insulator. As a result, the correlation between the vertical location of the trapped holes and the influence on C G -V G characteristics were revealed clearly. First, at the beginning of the stress, photogenerated holes are mainly trapped at the α-HIZO/SiO 2 interface and interfacial SiO 2 in contact with the interface, which induces the negative V th shift. Second, as the stress time increases, the holes start to be trapped in the spatially deeper insulator, which leads to an additional hump in the C G -V G characteristics at sufficiently low frequencies. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0018-9383 1557-9646 |
DOI: | 10.1109/TED.2016.2555332 |