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Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation
We investigated the effects of X-ray irradiation on the electrical characteristics of an amorphous In–Ga–Zn–O (a-IGZO) thin film transistor (TFT). The a-IGZO TFT showed a negative threshold voltage (V(TH)) shift of −6.2 V after 100 Gy X-ray irradiation. Based on spectroscopic ellipsometry (SE) and X...
Autores principales: | , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
The Royal Society of Chemistry
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9065737/ https://www.ncbi.nlm.nih.gov/pubmed/35515555 http://dx.doi.org/10.1039/c9ra03053k |
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author | Kim, Dong-Gyu Kim, Jong-Un Lee, Jun-Sun Park, Kwon-Shik Chang, Youn-Gyoung Kim, Myeong-Ho Choi, Duck-Kyun |
author_facet | Kim, Dong-Gyu Kim, Jong-Un Lee, Jun-Sun Park, Kwon-Shik Chang, Youn-Gyoung Kim, Myeong-Ho Choi, Duck-Kyun |
author_sort | Kim, Dong-Gyu |
collection | PubMed |
description | We investigated the effects of X-ray irradiation on the electrical characteristics of an amorphous In–Ga–Zn–O (a-IGZO) thin film transistor (TFT). The a-IGZO TFT showed a negative threshold voltage (V(TH)) shift of −6.2 V after 100 Gy X-ray irradiation. Based on spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS) analysis, we found that the Fermi energy (E(F)) changes from 2.73 eV to 3.01 eV and that the sub-gap state of D1 and D2 changes near the conduction band minimum (CBM) of the a-IGZO film after X-ray irradiation. These results imply that the negative V(TH) shift after X-ray irradiation is related to the increase in electron concentration of the a-IGZO TFT active layer. We confirmed that the sources for electron generation during X-ray irradiation are hydrogen incorporation from the adjacent layer or from ambient air to the active layer in the TFT, and the oxygen vacancy dependent persistent photocurrent (PPC) effect. Since both causes are reversible processes involving an activation energy, we demonstrate the V(TH) shift recovery by thermal annealing. |
format | Online Article Text |
id | pubmed-9065737 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | The Royal Society of Chemistry |
record_format | MEDLINE/PubMed |
spelling | pubmed-90657372022-05-04 Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation Kim, Dong-Gyu Kim, Jong-Un Lee, Jun-Sun Park, Kwon-Shik Chang, Youn-Gyoung Kim, Myeong-Ho Choi, Duck-Kyun RSC Adv Chemistry We investigated the effects of X-ray irradiation on the electrical characteristics of an amorphous In–Ga–Zn–O (a-IGZO) thin film transistor (TFT). The a-IGZO TFT showed a negative threshold voltage (V(TH)) shift of −6.2 V after 100 Gy X-ray irradiation. Based on spectroscopic ellipsometry (SE) and X-ray photoelectron spectroscopy (XPS) analysis, we found that the Fermi energy (E(F)) changes from 2.73 eV to 3.01 eV and that the sub-gap state of D1 and D2 changes near the conduction band minimum (CBM) of the a-IGZO film after X-ray irradiation. These results imply that the negative V(TH) shift after X-ray irradiation is related to the increase in electron concentration of the a-IGZO TFT active layer. We confirmed that the sources for electron generation during X-ray irradiation are hydrogen incorporation from the adjacent layer or from ambient air to the active layer in the TFT, and the oxygen vacancy dependent persistent photocurrent (PPC) effect. Since both causes are reversible processes involving an activation energy, we demonstrate the V(TH) shift recovery by thermal annealing. The Royal Society of Chemistry 2019-07-03 /pmc/articles/PMC9065737/ /pubmed/35515555 http://dx.doi.org/10.1039/c9ra03053k Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by/3.0/ |
spellingShingle | Chemistry Kim, Dong-Gyu Kim, Jong-Un Lee, Jun-Sun Park, Kwon-Shik Chang, Youn-Gyoung Kim, Myeong-Ho Choi, Duck-Kyun Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation |
title | Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation |
title_full | Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation |
title_fullStr | Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation |
title_full_unstemmed | Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation |
title_short | Negative threshold voltage shift in an a-IGZO thin film transistor under X-ray irradiation |
title_sort | negative threshold voltage shift in an a-igzo thin film transistor under x-ray irradiation |
topic | Chemistry |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9065737/ https://www.ncbi.nlm.nih.gov/pubmed/35515555 http://dx.doi.org/10.1039/c9ra03053k |
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