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Hydrogen behavior under X-ray irradiation for a-IGZO thin film transistors.
- Source :
-
Applied Physics Letters . 1/6/2020, Vol. 116 Issue 1, p1-4. 4p. 1 Diagram, 3 Graphs. - Publication Year :
- 2020
-
Abstract
- We studied hydrogen (H) behavior in amorphous In-Ga-Zn-O (a-IGZO) films under X-ray irradiation by evaluating the threshold voltage (VTH) shift in a-IGZO thin film transistors (TFTs) with different H concentrations in the active layers. We fabricated three types of a-IGZO TFTs: (i) one without a buffer layer and postannealed in N2, (ii) one with a H-resolved buffer layer and postannealed in N2, and (iii) one with a H-resolved buffer layer and postannealed in a mixture of N2 and H2. All three TFTs showed a negative VTH shift after 100 Gy of X-ray exposure. The degree of VTH shift correlated with an increase in conductivity, which, in turn, corresponds to the H concentration in the active layer of the as-fabricated TFTs. Based on spectroscopic ellipsometry analysis, we confirmed a large increase in the donorlike H related D1 state after X-ray irradiation in high-H concentration a-IGZO films. In addition, an increase in the number of H2 molecules in a-IGZO films after X-ray irradiation was observed via thermal desorption spectroscopy analysis. Therefore, we conclude that the increase in conductivity and/or the resulting negative VTH shift in a-IGZO TFTs during X-ray irradiation can be attributed not only to the state transition from acceptorlike to donorlike H in the as-prepared a-IGZO but also to the incorporation of additional H radicals generated by X-ray irradiation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 116
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 141173103
- Full Text :
- https://doi.org/10.1063/1.5132372