Improving the electrical properties of InAs nanowire field effect transistors by covering them with Y2O3/HfO2 layers.
Improving the electrical properties of InAs nanowire field effect transistors by covering them with Y2O3/HfO2 layers.
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DOI：
10.1039/c8nr05680c
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发表时间：
2018-10
期刊：
影响因子：
6.7
通讯作者：
Tong Li;Rui Shen;Mei Sun;D. Pan;Jingmin Zhang;Jun Xu;Jianhua Zhao;Qing Chen
中科院分区：
文献类型：
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作者：
Tong Li;Rui Shen;Mei Sun;D. Pan;Jingmin Zhang;Jun Xu;Jianhua Zhao;Qing Chen
准一维半导体材料由于其在缩小晶体管尺寸方面的优异性能而受到越来越多的关注。然而，在准一维纳米线（NW）晶体管中，它们的表面和界面特性起着非常重要的作用，主要是由于大的表面与体积比的纳米线和表面散射，这降低了它们的载流子迁移率。在此，我们开发了一种新的方法来覆盖沟道表面的InAs NW场效应晶体管（FET）与Y2 O3/HfO 2层，以改善其电性能。我们成功地制作了9个FET，并测量了它们的电学性能，这些电学性能在沉积Y2 O3/HfO 2层后得到了改善，包括通态电流的增加，关态电流的减少，介电常数的增加，电子迁移率的增加和亚阈值摆幅的减少。通过比较Y_2O_3/HfO_2覆盖层与未覆盖层或未退火的FET的性能，我们证明了Y_2O_3/HfO_2复合层而不是仅仅Y_2O_3或HfO_2层改善了FET的电学性能。Cs校正的高分辨率扫描透射电子显微镜研究表明，Y实际上可以扩散穿过天然氧化物层（确认为InOx）并到达InAs纳米线的表面。我们的研究结果表明，所需的特性Y2 O3和HfO 2的表面钝化提高了InAs NW FET的电性能，其中Y2 O3起着重要的作用，以修改和稳定之间的界面InAs NW和外部介质层。此外，该方法也适用于其他III-V族材料。
Quasi-one-dimensional semiconducting materials have attracted increasing attention due to their excellent ability to downscale the size of transistors. However, in quasi-one-dimensional nanowire (NW) transistors, their surface and interface properties play a very important role mainly due to the large surface-to-volume ratio of NWs and surface scattering, which degrade their carrier mobility. Herein, we developed a new method to cover the channel surface of InAs NW field effect transistors (FETs) with Y2O3/HfO2 layers to improve their electrical properties. We successfully fabricated nine FETs and measured their electrical properties, which improve after depositing the Y2O3/HfO2 layers, including an increase in on-state current, decrease in off-state current, increase in transconductance, increase in electron mobility and decrease in subthreshold swing. By comparing the properties of Y2O3/HfO2-covered devices with that of the FETs fabricated without the Y2O3 covering or without annealing, we prove that it is the combined Y2O3/HfO2 layers instead of only the Y2O3 or HfO2 layer that improve the electrical properties of the FETs. The Cs-corrected high-resolution scanning transmission electron microscopy study demonstrates that Y can actually diffuse through the native oxide layer (confirmed to be InOx) and reach the surface of the InAs NWs. Our results indicate that the desirable characteristics of Y2O3 and the surface passivation by HfO2 improve the electrical properties of the InAs NW FETs, in which Y2O3 plays an important role to modify and stabilize the interface between the InAs NWs and the outside dielectric layer. Furthermore, this method should also be applicable to other III-V materials.