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Title: Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress

Abstract

Oxide semiconductor thin-film transistors can show anomalous behavior under bias stress. Two types of anomalies are discussed in this paper. The first is the shift in threshold voltage (V{sub TH}) in a direction opposite to the applied bias stress, and highly dependent on gate dielectric material. We attribute this to charge trapping/detrapping and charge migration within the gate dielectric. We emphasize the fundamental difference between trapping/detrapping events occurring at the semiconductor/dielectric interface and those occurring at gate/dielectric interface, and show that charge migration is essential to explain the first anomaly. We model charge migration in terms of the non-instantaneous polarization density. The second type of anomaly is negative V{sub TH} shift under high positive bias stress, with logarithmic evolution in time. This can be argued as electron-donating reactions involving H{sub 2}O molecules or derived species, with a reaction rate exponentially accelerated by positive gate bias and exponentially decreased by the number of reactions already occurred.

Authors:
 [1];  [2]; ; ; ;  [3];  [4]
  1. LPICM, CNRS, Ecole Polytechnique, Université Paris Saclay, 91128, Palaiseau (France)
  2. Engineering Department, University of Cambridge, Cambridge, CB3 0FA (United Kingdom)
  3. i3N/CENIMAT, Department of Materials Science, Faculty of Science and Technology, Universidade NOVA de Lisboa and CEMOP/UNINOVA, Campus de Caparica, 2829-516 Caparica (Portugal)
  4. Holst Centre/TNO, Eindhoven, 5656 AE (Netherlands)
Publication Date:
OSTI Identifier:
22611380
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Advances; Journal Volume: 6; Journal Issue: 8; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DIELECTRIC MATERIALS; INTERFACES; MOLECULES; OXIDES; POLARIZATION; SEMICONDUCTOR MATERIALS; STRESSES; THIN FILMS; TRANSISTORS; TRAPPING

Citation Formats

Jin, Jong Woo, Nathan, Arokia, E-mail: an299@cam.ac.uk, Barquinha, Pedro, Pereira, Luís, Fortunato, Elvira, Martins, Rodrigo, and Cobb, Brian. Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress. United States: N. p., 2016. Web. doi:10.1063/1.4962151.
Jin, Jong Woo, Nathan, Arokia, E-mail: an299@cam.ac.uk, Barquinha, Pedro, Pereira, Luís, Fortunato, Elvira, Martins, Rodrigo, & Cobb, Brian. Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress. United States. doi:10.1063/1.4962151.
Jin, Jong Woo, Nathan, Arokia, E-mail: an299@cam.ac.uk, Barquinha, Pedro, Pereira, Luís, Fortunato, Elvira, Martins, Rodrigo, and Cobb, Brian. 2016. "Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress". United States. doi:10.1063/1.4962151.
@article{osti_22611380,
title = {Interpreting anomalies observed in oxide semiconductor TFTs under negative and positive bias stress},
author = {Jin, Jong Woo and Nathan, Arokia, E-mail: an299@cam.ac.uk and Barquinha, Pedro and Pereira, Luís and Fortunato, Elvira and Martins, Rodrigo and Cobb, Brian},
abstractNote = {Oxide semiconductor thin-film transistors can show anomalous behavior under bias stress. Two types of anomalies are discussed in this paper. The first is the shift in threshold voltage (V{sub TH}) in a direction opposite to the applied bias stress, and highly dependent on gate dielectric material. We attribute this to charge trapping/detrapping and charge migration within the gate dielectric. We emphasize the fundamental difference between trapping/detrapping events occurring at the semiconductor/dielectric interface and those occurring at gate/dielectric interface, and show that charge migration is essential to explain the first anomaly. We model charge migration in terms of the non-instantaneous polarization density. The second type of anomaly is negative V{sub TH} shift under high positive bias stress, with logarithmic evolution in time. This can be argued as electron-donating reactions involving H{sub 2}O molecules or derived species, with a reaction rate exponentially accelerated by positive gate bias and exponentially decreased by the number of reactions already occurred.},
doi = {10.1063/1.4962151},
journal = {AIP Advances},
number = 8,
volume = 6,
place = {United States},
year = 2016,
month = 8
}
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