The Ideal Nanowire Transistor-Materials Development for Contact-Doped ZnO Nanowires

直径约为20~100 nm的氧化锌纳米线是制作高性能场效应管(FET)和柔性电子集成电路的重要材料。单晶氧化锌纳米线很容易从溶液中制备，可以悬浮在各种溶剂中，以便在各种衬底上沉积和取向，并且具有超过20cm2/vs的电子迁移率。为了缩放的目的，有必要具有减小器件的沟道长度的策略。但是，由于氧化锌与金属接触界面处的势垒引起的接触电阻较大，限制了短沟道长度的氧化锌纳米线FET的性能。此外，制造具有短沟道的纳米线FET带来了使用高通量(即低分辨率)图案化技术连接小对象的挑战。我们建议通过制造具有自对准、选择性掺杂接触的氧化锌纳米线来解决这些挑战。我们将通过使用基于自组装单分子层的超薄栅电介质在一根单独的氧化锌纳米线上制作FET和电路来演示这些“理想”的n-i-n纳米线的工作原理。纳米线的总长度将超过10μm，使它们能够通过传统的光刻或印刷获得。由于掺杂了接触区，接触电阻将大大降低。通过调整纳米线中心本征区的长度，可以得到沟道长度小于100 nm的场效应管。

ZnO nanowires with a diameter of about 20 to 100 nm are of interest for high-performance field-effect transistors (FETs) and integrated circuits for flexible electronics. Single-crystalline ZnO nanowires are readily prepared from solution, can be suspended in a variety of solvents to allow deposition and alignment on a variety of substrates, and have electron mobilities exceeding 20 cm2/Vs. For scaling purpose it is necessary to have a strategy for reducing the channel length of the devices. But the performance of ZnO nanowire FETs with short channel length is limited by the large contact resistance that results from the energy barrier at the interface between the ZnO and the metal contacts. Also, making nanowire FETs with short channels introduces the challenge of connecting small objects using high-throughput (i.e., low-resolution) patterning techniques. We propose to solve these challenges by creating ZnO nanowires with self-aligned, selectively doped contacts. We will demonstrate the operation of these “ideal” n-i-n nanowires by making FETs and circuits on a single ZnO nanowire using an ultra-thin gate dielectric based on a self-assembled monolayer. The total length of the nanowires will exceed 10 μm, making them accessible by conventional photolithography or printing. Owing to the doped contact regions, the contact resistance will be greatly reduced. And by adjusting the length of the intrinsic region at the center of the nanowires we will obtain FETs with a channel length of less than 100 nm.