Schottky barrier heights at the interfaces between pure-phase InAs nanowires and metal contacts
Schottky barrier heights at the interfaces between pure-phase InAs nanowires and metal contacts
复制标题
纯相 InAs 纳米线与金属触点之间界面的肖特基势垒高度
DOI：
10.1063/1.4941391
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发表时间：
2016-02-07
影响因子：
3.2
通讯作者：
Xu, H. Q.
中科院分区：
文献类型：
--
作者：
Feng, Boyong;Huang, Shaoyun;Xu, H. Q.
了解金属接触-InAs纳米线界面处形成的肖特基势垒对于开发高性能InAs纳米线纳米电子和量子器件具有重要意义。在这里，我们报告的InAs纳米线场效应晶体管（FET）和肖特基势垒高度形成的接触纳米线接口的系统研究。所采用的InAs纳米线是通过分子束外延生长的，并且是高材料质量的单晶，并且器件是通过将纳米线与一系列不同功函数的金属直接接触而制成的。通过不同温度下的电气测量来表征所制造的InAs纳米线FET器件的特征，并从测量的沟道电流的温度和栅电压依赖性中提取肖特基势垒高度。我们发现，虽然接触金属的功函数是广泛传播的，肖特基势垒高度被确定为分布在35-55毫电子伏，表现出弱，但不可忽略的依赖于金属。在InAs纳米线沟道的推导费米能级被发现是在带隙和非常接近的导带。的费米能级钉扎的InAs纳米线的表面状态和移动钉扎费米能级引起的金属相关的界面状态的结果的物理起源进行了讨论。(C)2016 AIP Publishing LLC.
Understanding of the Schottky barriers formed at metal contact-InAs nanowire interfaces is of great importance for the development of high-performance InAs nanowire nanoelectronic and quantum devices. Here, we report a systematical study of InAs nanowire field-effect transistors (FETs) and the Schottky barrier heights formed at the contact-nanowire interfaces. The InAs nanowires employed are grown by molecular beam epitaxy and are high material quality single crystals, and the devices are made by directly contacting the nanowires with a series of metals of different work functions. The fabricated InAs nanowire FET devices are characterized by electrical measurements at different temperatures and the Schottky barrier heights are extracted from the measured temperature and gate-voltage dependences of the channel current. We show that although the work functions of the contact metals are widely spread, the Schottky barrier heights are determined to be distributed over 35-55 meV, showing a weak but not negligible dependence on the metals. The deduced Fermi level in the InAs nanowire channels is found to be in the band gap and very close to the conduction band. The physical origin of the results is discussed in terms of Fermi level pinning by the surface states of the InAs nanowires and a shift in pinned Fermi level induced by the metal-related interface states. (C) 2016 AIP Publishing LLC.