Effects of interface and bulk properties of gate-dielectric on the performance and stability of hydrogenated amorphous silicon thin-film transistors
| Autor: | M. Wakagi, K. Onisawa, Masahiko Ando |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Amorphous silicon
Materials science Silicon business.industry Gate dielectric Transistor General Physics and Astronomy chemistry.chemical_element Threshold voltage law.invention chemistry.chemical_compound chemistry Thin-film transistor law Optoelectronics business Layer (electronics) Quantum tunnelling |
| Zdroj: | Journal of Applied Physics. 118:234505 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.4938014 |
| Popis: | In order to investigate the effects of interface and bulk properties of gate insulator on the threshold voltage (Vth) and the gate-bias induced instability of hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs), four kinds of TFT structures were fabricated with SiNx and SiOx insulators stacked to make different combinations of the bulk and interface in the gate-dielectric layers. It was found that the Vth and the stability are independently controlled by tuning stoichiometry and thickness of the SiOx insertion layer between a-Si:H and SiNx. In TFTs with SiOx insertion layer of 50 nm thickness, on increasing oxygen/silicon (O/Si = x) ratio from 1.7 to 1.9, Vth increased from 0 V to 9 V. In these TFTs with a relatively thick SiOx insertion layer, positive Vth shift with negative bias stress was observed, confirmed to be due to defect creation in a-Si:H with the thermalization barrier energy of 0.83 eV. On reducing the thickness of the SiOx insertion layer down to approximately 1 nm, thin enou... |
| Databáze: | OpenAIRE |
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