Ultimate Scaling and Performance Potential of MoS2 Metal Oxide Semiconductor Field Effect Transistors (ULTIMOS2)

自2011年展示了具有二维（2D）二硫化钼（MoS2）通道的晶体管以来，石墨烯以外的二维材料获得了极大的关注。目前，这些电子应用材料的研究正在全球范围内进行，特别是以二硫化钼为最突出代表的二维过渡金属二硫化物（TMD）。MoS2具有相当大的带隙，因此在未来的数字电子产品中显示出很大的希望。然而，二硫化钼的加工技术仍处于起步阶段，有关二硫化钼晶体管潜力的许多问题仍未解决。这使得评估MoS2晶体管的性能和缩放限制以及判断这些器件在未来电子产品中的前景变得极其困难（如果不是不可能的话）。这种情况为本项目提供了动力，该项目专注于最终缩放的MoS2场效应晶体管（fet）的制造技术，理论和仿真。三个项目合作伙伴，两个来自德国，一个来自奥地利，在二维晶体管理论和（纳米）制造方面具有公认的和完全互补的专业知识，将对MoS2晶体管进行系统和探索性研究，并实现以下目标：•通过全面深入的实验和理论研究探索MoS2场效应管的缩放行为。•栅极长度低于10纳米的MoS2顶栅晶体管的演示。•考虑到加工限制、开关速度和非理想性（如电荷捕获相关问题），对最终规模化的单层和多层MoS2场效应管的前景进行批判性评估。•评估MoS2场效应管的p型操作潜力。合作伙伴将利用最先进的纳米制造技术来探索MoS2场效应管的缩放极限。将进行广泛的器件理论和仿真工作，以更好地了解TMD mosfet的物理和性能和缩放限制。理论工作将与实验密切相关，并用于精心设计MoS2场效应管，考虑到加工环境的具体情况以及电荷捕获效应等非理想情况。将建立完整的超尺度MoS2 fet工艺流程，包括栅极介电沉积、氮化硼封装和欧姆接触形成模块。从化学气相沉积薄膜中得到的测试结构和晶体管，包括用于提取开关延迟的高频晶体管，将进行彻底的分析和表征，其结果反过来将反馈到理论工作中。该项目将显著增强对MoS2 fet的物理，缩放行为和工艺集成的理解，并对其优缺点进行合理的评估。

2D materials beyond graphene have gained enormous attention since a transistor with a two-dimensional (2D) molybdenum disulfide (MoS2) channel was demonstrated in 2011. Currently, research on these materials for electronic applications is underway worldwide, in particular on the 2D transition metal dichalcogenides (TMD), with MoS2 as the most prominent representative. MoS2 possesses a sizeable bandgap and therefore shows great promise for future digital electronics. The processing technology for MoS2, however, is still in its infancy and many questions regarding the potential of MoS2 transistors are still open. This makes it currently extremely difficult, if not impossible, to assess the performance and scaling limits of MoS2 transistors and to judge the prospects of these devices for future electronics. This situation provides the motivation for the present project, which is focused on the fabrication technology, theory and simulation of ultimately scaled MoS2 field effect transistors (FETs). The three project partners, two from Germany and one from Austria, with recognized and perfectly complementary expertise in 2D transistor theory and (nano-) fabrication will conduct systematic and exploratory research on MoS2 transistors and address the following objectives:• Exploration of the scaling behavior of MoS2 FETs by thorough and comprehensive in-depth experimental and theoretical studies.• Demonstration of MoS2 top-gate transistors with sub-10 nm gate lengths.• Critical assessment of the prospects of ultimately scaled single- and multilayer MoS2 FETs considering processing constraints, switching speeds and non-idealities such as charge-trapping related issues.• Assessment of p-type operation potential of MoS2 FETs.The partners will utilize state-of-the-art nanofabrication technology to explore the scaling limits of MoS2 FETs. Extensive work on device theory and simulation will be performed to get better insights in the physics and in the performance and scaling limits of TMD MOSFETs. The theoretical work will be closely linked to the experiments and be used to elaborate suitable designs for MoS2 FETs, taking into account the specifics of the processing environment as well as non-idealities such as charge trapping effects. Complete process flows for ultra-scaled MoS2 FETs will be established, including modules for gate dielectric deposition, boron nitride encapsulation and Ohmic contact formation. The resulting range of test structures and transistors from chemical vapor deposited films, including high frequency transistors for extracting switching delays, will undergo thorough analysis and characterization whose results, in turn, will be fed back to the theoretical work. The project will result in significant enhancements of the understanding of the physics, the scaling behavior and the process integration of MoS2 FETs and in a sound assessment of their merits and drawbacks.