MRI: Development of Molecular Beam Expitaxy Apparatus for Growth of Two Dimensional Electron Gas Systems with Mobility of 100,000,000 cm2/Vs

MRI：开发用于生长迁移率达 100,000,000 cm2/Vs 的二维电子气系统的分子束外延装置

• 批准号: 0923369
• 负责人: Loren Pfeiffer
• 金额: $ 180万
• 依托单位: Princeton University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-10-01 至 2014-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0923369&HistoricalAwards=false
• 关键词: MRI; Development; Molecular; Beam; Expitaxy

0923369PfeifferPrinceton UniversityTechnical Abstract:The goal of the project is to construct a new molecular beam epitaxy (MBE) machine specifically designed to produce semiconductor hetero-structures of unprecedented purity and quality. The structures will be designed to yield two-dimensional electron system (2DES) samples having free carrier mobilities in excess of 100,000,000 cm2/Vs at cryogenic temperatures. At the low level of chemical and structural impurities envisioned, the free 2D electrons will interact primarily with each other through the many-body Coulomb interaction. The availability of such samples will enable an unprecedented level of inquiry into a broad range of fundamental questions in many-body phenomena in condensed matter physics. In the past, as the quality of 2D hetero-structures has improved, new physics has been discovered, that has led to two Nobel Prizes. These high quality 2DES are also expected to be important for the next generation of technology. They are crucial, for example, in examining topological approaches in quantum computing.Carrier mobility is a direct indication of semiconductor crystalline quality. Recent experiments have revealed the current record 2D electron mobility of 36,000,000 cm2/Vs is likely limited by residual chemical impurities located within the GaAs conducting channel. These impurities can arise from multiple sources: vacuum out-gassing and breakdown of the furnace parts containing the molten elemental sources in the MBE machine, chemical impurities in the elemental sources themselves, and leaks or out-gassing of the MBE chamber and the substrate heating equipment. In the new machine, improved vacuum pumping and the introduction of a novel vacuum cryopump will substantially reduce the levels of critical impurities. Based on recent results and calculations, we predict the new machine will be able to grow samples with carrier mobilities in excess of 100,000,000 cm2/Vs.Layman?s Abstract:The goal of the proposed project is a new crystal growth machine specifically designed to produce semiconductor crystals of record quality and purity. In present day crystals the free conduction electrons scatter off fixed residual chemical impurities, or off the neighboring conduction electrons. With this new MBE (Molecular Beam Epitaxy) machine we expect to produce crystals with strongly reduced impurity levels, so that the dominant scattering that the free electrons suffer will almost exclusively be from other free electrons. The electrons will be able to easily move about without running into fixed impurities, thus leading to the record ?mobility? in the project title. Such samples will enable an unprecedented level of inquiry into a broad range of fundamental questions in condensed matter physics. In the past, as crystal purity levels have improved, new results were discovered which led to Physics Nobel Prizes in 1985, and 1998. Such near-perfect crystals are also important for long range technological applications ? such as new approaches to computing after the current shrinking of microchips according to ?Moore?s Law? becomes no longer feasible. The MBE machine to be constructed will have record quality of vacuum inside ? fewer impurity molecules will be inside to contaminate the growing semiconductor crystal than in any other crystal growth machine in the world. The work will take place at the Princeton Institute for the Science and Technology of Materials and the Department of Electrical Engineering at Princeton University. About 150 students and researchers across the US will directly benefit from this project.

0923369PFeifferPrinceton UniversityTechnical摘要：该项目的目的是构建专门设计用于生成前所未有的纯度和质量的半导体异质结构的新分子束外延（MBE）机器。 这些结构将设计为产生二维电子系统（2DES）样品，其在低温温度下具有超过100,000,000 cm2/vs的游离载体迁移率。 在设想的化学和结构杂质的低水平上，游离的2D电子将主要通过多体库仑相互作用相互相互作用。 此类样品的可用性将使人们能够对凝结物理学中多体现象的广泛基本问题进行前所未有的询问。过去，随着2D异质结构的质量有所改善，发现了新的物理学，这导致了两项诺贝尔奖。 这些高质量的2DE也对下一代技术很重要。 例如，在检查量子计算中的拓扑方法时，它们至关重要。载体迁移率是半导体晶体质量的直接指示。 最近的实验表明，当前创纪录的2D电子迁移率为36,000,000 cm2/vs，可能受到GAAS导电通道内的残余化学杂质的限制。这些杂质可能来自多种来源：真空吸尘器和炉子中包含MBE机器中包含熔融元素源的炉子的破坏，元素源本身中的化学杂质，以及MBE室和底物加热设备的泄漏或泄漏或泄漏。 在新机器中，改进的真空抽水和新型真空冷冻机的引入将大大降低关键杂质的水平。 根据最近的结果和计算，我们预测，新机器将能够种植具有超过100,000,000 cm2/vs.layman的载流量的样品，而不是摘要：拟议项目的目标是一种新的晶体生长机器，专门设计用于生产具有创纪录质量和纯度的半导体晶体。 在当今的晶体中，游离传导电子散布固定的残留化学杂质或邻近的传导电子。 使用这台新型MBE（分子束外延）机器，我们期望产生具有强大杂质水平的晶体，因此自由电子遭受的主要散射几乎完全来自其他自由电子。 电子将能够轻松地移动而不会遇到固定杂质，从而导致记录？移动性？在项目标题中。 这些样本将使人们能够对凝结物理学的各种基本问题进行空前的询问。过去，随着晶体纯度水平有所提高，发现了新的结果，这导致了1985年和1998年的诺贝尔奖。这种接近完美的晶体对于远程技术应用也很重要吗？例如，根据“摩尔法律”的定律，微芯片当前缩小了计算方法？变得不再可行。 要构造的MBE机器将具有创纪录的真空质量吗？与世界上任何其他晶体生长机器相比，内部杂质分子的内部污染分子更少。 这项工作将在普林斯顿大学材料科学技术学院和普林斯顿大学电气工程系进行。 美国大约有150名学生和研究人员将直接从该项目中受益。