Negative Capacitance Phosphorene Tunneling Field Effect Transistors

该项目旨在研究如何制造一种晶体管的问题，这种晶体管可以用比传统晶体管更少的能量在“开”和“关”状态之间切换。它试图通过将隧穿和铁电性两种机制与新兴的二维材料领域相结合，突破半导体芯片技术中一个被称为“光子”极限的基本问题。这种技术将是半导体行业的一个突破，导致更小的计算机芯片可以执行更多的功能，更容易集成到移动的和物联网应用中。该项目将成为研究生的理想培训基地，因为他们将能够同时研究对半导体行业至关重要的问题，同时探索量子力学，材料科学和器件物理的许多基本方面。这项工作的各个方面也将在本科半导体器件类，其中的结果提供了一个理想的例子，结合了几个“结束的路线图”的概念的设备。最后，该项目的成果将被纳入明尼苏达大学的暑期学校推广计划，并用于K-12推广活动，如课堂演示和互动活动，这些活动可以产生对工程和科学事业的兴奋。拟议研究的目标是设计，制造，表征和分析了一种新型的陡亚阈值斜率负电容隧穿场效应晶体管的特性。该器件结合了两种机制：费米函数滤波和负电容栅极滤波，以创建一个能够非常急剧地关断行为的器件，该器件远低于每十年60毫伏的电子极限。该器件进一步利用磷烯作为沟道材料，由于其窄的带隙和各向异性的有效质量，磷烯是用于隧穿晶体管的理想材料。研究范围和方法包括开发技术，以创建受控的异质结构在磷烯与单层精度，研究的取向依赖性的带带隧穿磷烯pn结，铁电材料的沉积和界面质量与磷烯的调查，制造的新的陡峭的亚阈值斜率器件的表征，和器件性能的预测模型的发展。拟议工作的智力意义在于，它解决了与二维半导体和铁电材料相关的关键技术挑战，并回答了有关低能晶体管操作极限的基本问题，从而解决了半导体器件社区面临的最紧迫挑战之一。

The project intends to study the problem of how to create a transistor that can be switched between its "on" and "off" states with less energy than a conventional transistor. It attempts to break through a fundamental problem in semiconductor chip technology called the "thermionic" limit by combining two mechanisms, tunneling and ferroelectricity, with the emerging field of two-dimensional materials. Such a technology would be a breakthrough in the semiconductor industry leading to smaller computer chips that could perform more functions, and be more easily integrated into mobile and internet-of-things applications. The project will be an ideal training ground for graduate students, as they will simultaneously be able to work on a problem of vital importance to the semiconductor industry, while at the same time, explore many fundamental aspects of quantum mechanics, material science and device physics. Aspects of this work will also be utilized in an undergraduate semiconductor device class, where the results provide an ideal example of a device that combines several "end-of-the-roadmap" concepts. Finally, the results from this project will be incorporated into a summer school outreach program at the University of Minnesota and be utilized for K-12 outreach activities such as in-class demonstrations and interactive activities that can generate excitement about engineering and scientific careers in general.The goal of the proposed research is to design, fabricate, characterize and analyze the properties of a novel steep-subthreshold slope negative capacitance tunneling field-effect transistor made using the two-dimensional nanomaterial, phosphorene. The device combines two mechanisms: Fermi-function filtering and negative capacitance gate dielectrics to create a device capable of extremely sharp turn-off behavior that is well below the thermionic limit of 60 millivolts per decade. The device further utilizes phosphorene as the channel material, which is an ideal material for tunneling transistors due to its narrow band gap and anisotropic effective mass. The research scope and methods include the development of techniques to create controlled heterostructures in phosphorene with monolayer precision, study of the orientation-dependence of band-to-band tunneling in phosphorene pn junctions, investigation of ferroelectric material deposition and interface quality with phosphorene, fabrication of characterization of the novel steep-subthreshold slope device, and development of a predictive model of the device performance. The intellectual significance of the proposed work is that it addresses key technical challenges associated with two-dimensional semiconductors and ferroelectric materials and answers fundamental questions about the ultimate limits of low-energy transistor operation, thereby tackling one of the most pressing challenges facing the semiconductor device community.