Abstract We report the effect of germanium doping on the active layer of amorphous Zinc–Tin-Oxide (a-ZTO) thin film transistor (TFT). Amorphous thin film samples were prepared by RF magnetron sputtering using single targets composed of Zn2Ge0.05Sn0.95O4 and Zn2SnO4 with variable oxygen contents in the sputtering gases. In comparison with undoped, Ge-doped a-ZTO films exhibited five order of magnitude lower carrier density with a significantly higher Hall-mobility, which might be due to suppressed oxygen vacancies in the a-ZTO lattice since the Ge substituent for the Sn site has relatively higher oxygen affinity. Thus, the bulk and interface trap densities of Ge-doped a-ZTO film were decreased one order of magnitude to 7.047 × 1018 eV−1cm−3 and 3.52 × 1011 eV−1cm−2, respectively. A bottom-gate TFT with the Ge-doped a-ZTO active layer showed considerably improved performance with a reduced SS, positively shifted Vth, and two orders of magnitude increased Ion/Ioff ratio, attributable to the doped Ge ions.

中文翻译：

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Ge掺杂对非晶Zn-Sn-O薄膜电学性能的影响

摘要 我们报告了锗掺杂对非晶氧化锌 (a-ZTO) 薄膜晶体管 (TFT) 有源层的影响。使用由 Zn2Ge0.05Sn0.95O4 和 Zn2SnO4 组成的单个靶材，在溅射气体中具有不同的氧含量，通过射频磁控溅射制备非晶薄膜样品。与未掺杂的 a-ZTO 薄膜相比，Ge 掺杂的 a-ZTO 薄膜表现出低五个数量级的载流子密度和显着更高的霍尔迁移率，这可能是由于 a-ZTO 晶格中的氧空位受到抑制，因为 Sn 位的 Ge 取代基具有相对较高的氧亲和力。因此，掺 Ge 的 a-ZTO 薄膜的体密度和界面陷阱密度分别降低了一个数量级，分别为 7.047 × 1018 eV-1cm-3 和 3.52 × 1011 eV-1cm-2。