Microscopic Studies of Schottky Barrier Nano-Contacts and Nano-Structured Metal/Semiconductor and Metal/Insulator Interfaces

肖特基势垒纳米接触和纳米结构金属/半导体和金属/绝缘体界面的微观研究

• 批准号: 0505165
• 负责人: Jonathan Pelz
• 金额: --
• 依托单位: Ohio State University Research Foundation -DO NOT USE
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-07-01 至 2009-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0505165&HistoricalAwards=false
• 关键词: Microscopic; Studies; Schottky; Barrier; Nano

This project addresses fundamental materials science details of Schottky barrier nano contacts and nano-structured metal/semiconductor and metal/insulator interfaces The approach incorporates three sets of experiments to image, quantify, and model nm-scale electronic properties of metal-semiconductor (MS) and metal-insulator (MI) Schottky-barrier (SB) interfaces, which have nm-scale dimensions or nm-scale internal structure. Local SB properties will be measured with nm-resolution ballistic electron emission microscopy (BEEM), and 3D electrostatic modeling will be used to compare and correlate nm-scale SB properties with the total device electrical response. The first set of experiments will study SB nanocontacts where the semiconductor dimension is systematically varied down to ~ 1 nm, to probe how small-size effects (e.g. quantum-confinement and "environmental pinning") affect carrier injection into semiconductor nanostructures. A structure will be used consisting of a SB made on the cleaved face of a GaAs/AlGaAs heterostructure containing quantum wells (QWs) of different, precisely known width. These samples will also be used as nm-sized "apertures" for quantitative study of lateral hot-electron scattering and relaxation in metal films, including scattering processes within and between individual metal grains. A second set of experiments will use different sample structures for nm-resolution SB studies while a strong gate-field is applied to the SB contact. The main objective is to image and quantify how strong geometry-induced fields at defects and device edges affect the local SB properties and carrier injection through the SB. These sample structures will also be used for Ambipolar BEEM measurements, where the electron barrier and the hole barrier can be quantified at the same location, for example close to a particular defect. The third set of experiments will study metal-oxide-silicon (MOS) structures, where the metal film is a laterally nanostructured mixture of metals with very different workfunctions. The goal is to image, quantify, and model how lateral nm-scale structure in the metal film affects the local and average barrier height at the metal/oxide interface, and hence the resulting local and average electric fields in the oxide film and at the critical oxide/Si interface. A related goal is to investigate metal bilayers and other nanostructured metal films as possible "tunable workfunction" metals for future devices (MOSFETs). %%% The project addresses fundamental research issues associated with materials having technological relevance in nanoelectronics. An important feature of the project is the strong emphasis on education, with emphasis on integration of research and education. This project will provide a highly interdisciplinary and collaborative environment for graduate and undergraduate student training. Students are expected to develop a broad knowledge and training base by combining equipment construction, semiconductor processing, advanced experiments with novel equipment, numerical modeling, and frequent interactions with collaborators. Undergraduate and underrepresented students will continue to be actively recruited. Additionally, the PI will continue active involvement with science outreach, particularly in K-6 with science demonstrations, student interactions, and teacher mentoring.

该项目涉及肖特基势垒纳米接触和纳米结构金属/半导体和金属/绝缘体界面的基本材料科学细节。该方法结合了三组实验，以成像，量化和建模金属-半导体（MS）和金属-绝缘体（MI）肖特基势垒（SB）界面的纳米级电子特性，这些界面具有纳米级尺寸或纳米级内部结构。局部SB属性将使用nm分辨率弹道电子发射显微镜（BEEM）测量，3D静电建模将用于比较和关联nm级SB属性与总器件电响应。第一组实验将研究SB纳米接触，其中半导体尺寸系统地变化到约1 nm，以探测小尺寸效应（例如量子限制和“环境钉扎”）如何影响载流子注入半导体纳米结构。将使用由在GaAs/AlGaAs异质结构的解理面上制成的SB组成的结构，该异质结构包含不同的、精确已知宽度的量子威尔斯（QW）。这些样品也将被用作纳米尺寸的“孔径”，用于定量研究金属薄膜中的横向热电子散射和弛豫，包括单个金属颗粒内和之间的散射过程。第二组实验将使用不同的样品结构的纳米分辨率SB的研究，而一个强大的门场施加到SB接触。主要目标是图像和量化如何强大的几何形状引起的领域在缺陷和设备边缘影响本地SB属性和载流子注入通过SB这些样品结构也将用于双极BEEM测量，其中电子势垒和空穴势垒可以量化在同一位置，例如接近一个特定的缺陷。第三组实验将研究金属氧化物硅（MOS）结构，其中金属膜是具有非常不同功函数的金属的横向纳米结构混合物。我们的目标是图像，量化，并模拟如何横向纳米尺度的结构在金属膜影响的局部和平均势垒高度在金属/氧化物界面，因此产生的局部和平均电场的氧化物膜和在关键的氧化物/硅界面。一个相关的目标是研究金属双层和其他纳米结构的金属薄膜作为未来器件（MOSFET）的可能的“可调功函数”金属。该项目解决了与纳米电子技术相关的材料相关的基础研究问题。该项目的一个重要特点是高度重视教育，强调研究与教育的融合。该项目将为研究生和本科生的培训提供一个高度跨学科和协作的环境。学生将通过结合设备建造，半导体加工，先进的实验与新设备，数值建模以及与合作者的频繁互动来开发广泛的知识和培训基础。本科生和代表性不足的学生将继续积极招聘。此外，PI将继续积极参与科学推广，特别是在K-6与科学演示，学生互动和教师指导。