Engineering Atomic Layer Deposited Contact Interfaces to Low-Dimensional Nanomaterials for Improved Scaled Transistor Performance

将原子层沉积接触界面设计为低维纳米材料，以提高晶体管的性能

• 批准号: 1508573
• 负责人: Aaron Franklin
• 金额: $ 35.81万
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2018-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1508573&HistoricalAwards=false
• 关键词: Engineering; Atomic; Layer; Deposited; Contact

AbstractNontechnical:Nanomaterials offer many advantages for electronic devices, with the potential to enable electronics that operate at lower power and are transparent or flexible. The foremost limit to nanomaterial devices of any type is the necessary interfaces to the nanomaterial, primarily the contacts. Contacts are essential for injecting and extracting electrical current in nanomaterials, and are the least understand aspect of such devices. This project takes several new approaches to understanding and improving the electrical contact to nanomaterials in order to enable their use in exciting electronic applications. A custom-built material deposition system will be used to modify the nanomaterial surface and allow for the atomically controlled growth of various contact materials. The resultant improvement of the contacts to nanomaterials will provide the nanoelectronics and optoelectronics communities with key information for improving their device design and fabrication approaches. From carrier collection interfaces in solar cells to contacts in scaled low-power transistors, results from this project will impact the Grand Challenges by enabling more efficient solar energy and lower energy electronics. Further, an improved understanding of interfaces to nanomaterials will open the way for new device concepts. This project will also be impactful in promoting educational diversity as it will be carried out by two female graduate students, one of whom is a NSF Graduate Research Fellow. Further, the extensive interest in nanomaterials among high school and undergraduate students makes this project ideal for attracting involvement of underrepresented minorities around Duke through several established and new outreach programs. Technical:The ultimate limits of nanomaterial-based devices are defined by the necessary contact interfaces. Especially when it comes to van der Waals-type nanomaterials (focus of this project are: graphene, 2D crystals, carbon nanotubes), where there are no surface states for interfacial bonding, interaction with contacts is a substantial bottleneck. In this project, new techniques for enabling atomic layer deposition (ALD) nucleation at the contact interface will be used to improve understanding and quality of interfacial electron transport, thereby amplifying device performance. ALD provides conformal thin films of various conducting materials with atomic layer precision. Tuning the ALD process conditions allows for controlled alteration of metal work function and crystallinity. However, ALD on nanomaterials is typically not possible due to the inert nanomaterial surface. This project will use an advanced plasma-enhanced ALD system that is linked through an ultra-high vacuum load lock to a physical vapor deposition (PVD) tool with a low energy broad beam ion source. This in situ PVD and ion beam will be used to modify the surface of nanomaterials in a variety of fashions to create nucleation sites for subsequent ALD. For instance, varying the ion beam energy will allow tuning between surface adsorbate depositions to dangling bond creation in the nanomaterial contact areas using various constituents' including H2, N2, Ar, and O2. The resultant contact interfaces will be characterized structurally (optical spectroscopy) and electrically (FETs). In addition to being the first study of ALD contacts to nanomaterials, this project will yield devices with improved performance, including at scaled contact dimensions for advanced electronics. The way will be opened for applying these ALD-formed contacts to nanomaterials in a myriad of promising applications, from high-performance transistors to solar cells.This project is jointly funded by the Electronics, Photonics, and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber Systems (ECCS) and the Electronic and Photonic Materials (EPM) Program in the Division of Materials Research (DMR).

摘要非技术性：纳米材料为电子设备提供了许多优势，并有可能使电子设备能够以较低的功率运行并且透明或灵活。 任何类型的纳米材料设备的最大限制是纳米材料的必要接口，主要是接触。 触点对于在纳米材料中注入和提取电流至关重要，并且是此类设备的最不理解的方面。 该项目采用了几种新方法来理解和改善与纳米材料的电气接触，以便能够在令人兴奋的电子应用中使用。 定制的材料沉积系统将用于修饰纳米材料表面，并允许各种接触材料的原子控制。 纳米材料的接触的最终改进将为纳米电子学和光电群落提供关键信息，以改善其设备设计和制造方法。 从太阳能电池中的载流子收集界面到缩放低功率晶体管的触点，该项目的结果将通过实现更有效的太阳能和较低的能量电子来影响巨大的挑战。 此外，对纳米材料接口的改进理解将为新设备概念开辟道路。 该项目还将在促进教育多样性方面产生影响，因为这将由两名女研究生进行，其中一名是NSF研究生研究员。 此外，在高中和本科生中，人们对纳米材料的广泛兴趣使该项目是通过几个既定和新的外展计划吸引杜克（Duke）周围代表不足的少数民族参与的理想选择。技术：基于纳米材料的设备的最终限制是由必要的接触界面定义的。 尤其是当涉及范德华型纳米材料（该项目的重点是：石墨烯，2D晶体，碳纳米管），那里没有界面粘结的表面状态，与触点相互作用是一种实质性的瓶颈。 在该项目中，将使用接触接口处的原子层沉积（ALD）成核的新技术来提高界面电子传输的理解和质量，从而扩大设备性能。 ALD提供具有原子层精度的各种导电材料的保形薄膜。 调整ALD过程条件可以控制金属工作功能和结晶度的改变。 但是，由于惰性纳米材料表面，通常无法进行纳米材料的ALD。 该项目将使用高级等离子体增强的ALD系统，该系统通过超高真空载荷锁链接到具有低能宽光束离子源的物理蒸气沉积（PVD）工具。 该原位PVD和离子束将用于修改各种时尚中纳米材料的表面，以创建用于后续ALD的成核位点。 例如，改变离子束能量将允许使用各种成分（包括H2，N2，AR和O2）在纳米材料接触区域中调整表面吸附物沉积以在纳米材料接触区域悬挂键。 所得的接触界面将在结构（光谱）和电（FET）上表征。 除了是对纳米材料的ALD接触的首次研究外，该项目还将产生具有提高性能的设备，包括在高级电子产品的缩放接触尺寸上。 The way will be opened for applying these ALD-formed contacts to nanomaterials in a myriad of promising applications, from high-performance transistors to solar cells.This project is jointly funded by the Electronics, Photonics, and Magnetic Devices (EPMD) Program in the Division of Electrical, Communications and Cyber​​ Systems (ECCS) and the Electronic and Photonic Materials (EPM) Program in the Division of Materials Research （DMR）。