GOALI: Negative Capacitance in Epitaxial Oxide Heterostructures

目标：外延氧化物异质结构中的负电容

• 批准号: 1207342
• 负责人: John Ekerdt
• 金额: $ 48万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1207342&HistoricalAwards=false
• 关键词: GOALI; Negative; Capacitance; Epitaxial; Oxide

This project is jointly funded by the Electronic and Photonic Materials Program (EPM) and Ceramics Program (CER) in the Division of Materials Research (DMR).Technical Description: This GOALI project explores the fundamental materials science problems of integrating a single-crystalline, single-domain ferroelectric material (with polarization out of plane) onto silicon. A ferroelectric layer in series with a dielectric is predicted to produce negative capacitance, which will lower the sub-threshold slope of a field effect transistor and significantly lower the power dissipated in a transistor. This research project develops the materials and the fundamental understanding necessary to make the predictions a reality. Molecular beam epitaxy is used to grow strontium titanate epitaxially on single-crystal silicon as a buffer layer for the nucleation and growth of single-crystal ferroelectric films, such as barium titanate. The research explores routes to integrate these single- crystal layers on silicon, approaches to achieving out-of-plane polarization in the ferroelectric layer for thicknesses up to 50 nanometers, approaches to achieving a single-domain ferroelectric state, and integration of these layers into transistor devices to harness the negative capacitance state of the heterolayers and realize sub-threshold slopes less than 60 millivolts per decade. The experimental growth studies are guided by ab-initio theory, and materials properties are characterized using in-situ and ex-situ methods.Non-technical Description: Scaling of the complementary metal oxide semiconductor (CMOS) technology is at the heart of Moore's law; it is driven by the desire to produce ever faster field effect transistors. However, the faster the transistor is the more heat it generates in the switching process. New device concepts are required to enable significantly lower power dissipation and to realize the full speed potential for the smaller devices. This research project explores one of the new device concepts of using a ferroelectric/dielectric composite film in place of the dielectric that is currently used in field effect transistors - a concept that is yet to be realized because of the challenges in growing the layers with the proper crystal structure and orientation on the silicon surface that forms the transistor. The research combines an interdisciplinary team and explores growth and properties of barium titanate layers (the ferroelectric) on strontium titanate (the dielectric) on a silicon wafer. The research partners university researchers with a technology leader in advanced device design to broaden the student experience as they are exposed to problem definition that keeps the end goal of developing a viable technology front and center. The outreach activities are aimed at attracting high-school female students to physical sciences and engineering; in collaboration with the physics instructors in local high schools, the students spend summers in research groups at the University of Texas at Austin and participate in real science in a supportive environment.

该项目由材料研究部（DMR）的电子和光子材料计划（EPM）和陶瓷计划（CER）共同资助。技术描述：该守门员项目探讨了将单晶体，单层，单个域的小型铁电材料整合到硅的基本材料科学问题。预计用介电的铁电层串联会产生负电容，这将降低场效应晶体管的子阈值斜率，并显着降低晶体管中消散的功率。该研究项目开发了使预测成为现实所必需的材料和基本理解。分子束外延用于在单晶硅上外司法钛酸盐作为一种缓冲层，作为单晶铁电膜的成核和生长的缓冲层，例如钛酸钡。该研究探讨了将这些单晶层整合在硅上的途径，在铁电层中实现平面外极化的方法，以使其厚度高达50纳米，这是实现单层铁电态的方法，以及将这些层整合到跨性别的60层群中，以避免跨跨型群体，以避免跨越的60型群体和近距离的人群，并实现了彼此的群体。每十年毫美。实验生长研究以Ab-Initio理论为指导，材料特性的特征是使用原位和原位方法的特征。没有技术描述：补充金属氧化物半导体（CMOS）技术的缩放是摩尔定律的核心；它是由产生更快的场效应晶体管的愿望所驱动的。但是，晶体管在切换过程中产生的热量就越快。需要新的设备概念以显着降低功率耗散，并实现较小设备的全速潜力。该研究项目探讨了使用铁电/介电复合膜代替介电膜的新设备概念之一，该介质目前用于现场效应晶体管中 - 这一概念尚未实现，因为在形成晶体管的硅表面上具有适当的晶体结构和方向的层面上面临的挑战。该研究结合了一个跨学科的团队，并探索了钛酸钡层（铁电）在硅酸中盐（The Dielectric）上的生长和特性。研究合作伙伴大学的研究人员拥有高级设备设计技术领导者，以扩大学生的体验，因为他们接触了问题定义，这是开发可行的技术界和中心的最终目标。外展活动旨在吸引高中女学生进入体育科学和工程学；与当地高中的物理讲师合作，学生们在德克萨斯大学奥斯汀分校的研究小组中度过了夏天，并在支持环境中参加了真正的科学。