Low Resistance Contacts on Atomically Thin Body Semiconductors for Energy Efficient Electronics (LoResCon)

用于节能电子产品的原子薄体半导体上的低电阻触点 (LoResCon)

• 批准号: EP/T026200/1
• 负责人: Manish Chhowalla
• 金额: $ 119.79万
• 依托单位: University of Cambridge
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FT026200%2F1
• 关键词: Low; Resistance; Contacts; Atomically; Thin

The high performance, at relatively low energy cost in today's field effect transistors (FETs), is achieved by decades long optimization of electrical contacts that has allowed the miniaturization of the semiconductor channel down to nanoscale dimensions. However, decreasing dimensions of the devices leads to power dissipation in the off state (leakage current) and other detrimental consequences that are collectively referred to as short channel effects. Emergent semiconductors, such as MoS2, that are naturally atomically thin can in principle mitigate several concerns related to short channel effects. In FETs with atomically thin body (ATB) channels, the charge carriers are confined within the sub 1nm thick semiconductor so that application of gate voltage influences all the carriers uniformly. This prevents leakage currents and allows the FETs to be sharply turned on or off. The fact that atomically thin individual layers of bulk-layered materials can be isolated necessitates the absence of dangling bonds in 2D semiconductors, which means that surface roughness effects are minimized. Recent research in FETs suggests that such ATB materials could be one pathway towards future energy efficient electronics that can operate down to milli volts using the current CMOS manufacturing platform. While the benefits of 2D semiconductor FETs in addressing short channel effects are obvious, they still possess lower performance compared to state-of-the-art silicon and III-V semiconductor analogues due the high contact resistance. To reap the benefits of ultra-short channel (sub 10 nm node) and tunnel FETs, contact resistances must be reduced down to the quantum limit. The contact resistance acts as a severe source-choke. This leads to degradation in the performance of the transistor, because the current depends very strongly on the effective gate voltage at the source injection point. The high contact resistance between metals and 2D semiconductors is a major barrier to their implementation in high performance short channel electronics. This proposal aims to pioneer low electrical resistance contacts on atomically thin body (ATB) transition metal dichalcogenide (TMD) semiconductors to enable the exploration of fundamental phenomena that is currently limited by poor contacts - with the motivation to understand key processes that underpin the behavior of short channel and tunnel field effect transistors so that devices with unprecedented energy efficiency and performance can be realized. The proposal builds on the our recent breakthrough on van der Waals contacts on ATB semiconductors published in Nature (April 2019) and strategic investments in the Materials for Energy-Efficient ICT theme at Cambridge through the Sir Henry Royce Institute. Our ambition is to realize low resistance contacts on ATB semiconductors that will allow a broad range of device communities to address and overcome the long-standing challenge of making good electrical contacts on low dimensional materials. The proposed work will underpin and impact ongoing programmes and initiatives aligned with several EPSRC priority areas. This includes adaptation of low resistance contacts for in operando characterization of battery materials using microelectrochemical cells and low resistance contacts for organic semiconductors and perovskites. This proposal aims to bring a step-change and establish an internationally leading programme in low resistance contacts for high-performance electronics based on ATB semiconductors that will add value and connect a broad range of communities. The proposed work will open up new pathways for achieving in-depth fundamental knowledge of physics of novel devices based on ATB materials to accelerate their development towards technological readiness and commercialization in higher value-added products.

当今场效应晶体管 (FET) 的高性能和相对较低的能源成本是通过数十年的电接触优化实现的，这使得半导体通道小型化至纳米级尺寸。然而，器件尺寸的减小会导致关断状态下的功耗（漏电流）和其他不利后果，统称为短沟道效应。新兴半导体，例如MoS2，其天然厚度为原子级，原则上可以减轻与短沟道效应相关的一些问题。在具有原子薄体 (ATB) 沟道的 FET 中，电荷载流子被限制在亚 1nm 厚的半导体内，因此施加的栅极电压会均匀地影响所有载流子。这可以防止漏电流并允许 FET 快速导通或截止。事实上，原子级薄的层状材料的各个层可以被隔离，这就需要二维半导体中不存在悬空键，这意味着表面粗糙度的影响被最小化。最近对 FET 的研究表明，此类 ATB 材料可能成为未来节能电子产品的一种途径，这些电子产品可以使用当前的 CMOS 制造平台在低至毫伏的电压下工作。虽然 2D 半导体 FET 在解决短沟道效应方面的优势显而易见，但由于接触电阻较高，与最先进的硅和 III-V 半导体类似物相比，它们的性能仍然较低。为了获得超短沟道（亚 10 nm 节点）和隧道 FET 的优势，必须将接触电阻降低至量子极限。接触电阻充当严重的源扼流圈。这会导致晶体管性能下降，因为电流非常依赖于源极注入点处的有效栅极电压。金属和二维半导体之间的高接触电阻是其在高性能短沟道电子器件中实现的主要障碍。该提案旨在开创原子薄体（ATB）过渡金属二硫属化物（TMD）半导体上的低电阻接触，从而能够探索目前因接触不良而受到限制的基本现象 - 其动机是了解支撑其行为的关键过程。短沟道和隧道场效应晶体管使器件具有前所未有的能效和性能。该提案建立在我们最近在《自然》杂志（2019 年 4 月）上发表的关于 ATB 半导体的范德华接触方面的突破以及通过亨利·莱斯爵士研究所在剑桥大学对节能 ICT 材料主题进行的战略投资的基础上。我们的目标是在 ATB 半导体上实现低电阻接触，这将使广泛的设备社区能够解决并克服在低维材料上形成良好电接触的长期挑战。拟议的工作将支持并影响与 EPSRC 几个优先领域相一致的正在进行的计划和举措。这包括采用微电化学电池和有机半导体和钙钛矿的低电阻接触来调整低电阻接触，以用于电池材料的操作表征。该提案旨在实现重大变革，并在基于 ATB 半导体的高性能电子产品的低电阻触点方面建立国际领先的计划，从而增加价值并连接广泛的社区。拟议的工作将为深入了解基于 ATB 材料的新型器件的物理基础知识开辟新的途径，以加速其向高附加值产品的技术准备和商业化的发展。

项目成果

Nanoscale Characterisation of Heterointerfaces in 2D Materials

二维材料异质界面的纳米级表征

• DOI: http://dx.10.17863/cam.105989
• 发表时间: 2023
• 作者: Ramsden H

P-type electrical contacts for two-dimensional transition metal dichalcogenides

二维过渡金属二硫属化物的 P 型电接触

• DOI: http://dx.10.17863/cam.88987
• 发表时间: 2022
• 作者: Chhowalla M

P-type electrical contacts for 2D transition-metal dichalcogenides.

二维过渡金属二硫属化物的 P 型电接触。

• DOI: http://dx.10.17863/cam.96160
• 发表时间: 2022
• 作者: Wang Y

Epitaxial single-crystal hexagonal boron nitride multilayers on Ni (111).

Ni (111) 上外延单晶六方氮化硼多层膜。

• DOI: http://dx.10.1038/s41586-022-04745-7
• 发表时间: 2022
• 期刊: Nature
• 影响因子: 64.8
• 作者: Ma KY

Epitaxial single-crystal hexagonal boron nitride multilayers on Ni (111).

Ni (111) 上外延单晶六方氮化硼多层膜。

• DOI: http://dx.10.17863/cam.96369
• 发表时间: 2022
• 作者: Ma K