Isotopically Controlled Semiconductors: Diffusion and Nanocrystals

同位素控制半导体：扩散和纳米晶体

• 批准号: 0405472
• 负责人: Eugene Haller
• 金额: --
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-11-01 至 2009-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0405472&HistoricalAwards=false
• 关键词: Isotopically; Controlled; Semiconductors; Diffusion; Nanocrystals

This project addresses (1) the physics of atomic diffusion in crystalline thin film multilayer structures and (2) the properties of nano-particles composed of isotopically controlled semiconductors. Self-diffusion (i.e., isotope inter-diffusion) and dopant diffusion will be studied directly and simultaneously for the first time in strained and relaxed silicon-germanium (SiGe) multi-layer structures. The studies are designed to reveal the physics underlying the various diffusion mechanisms. The expected results will expand the fundamental solid-state knowledge base, may lead to the discovery of new diffusion processes, and will be of direct use to the designers of future SiGe electronic devices. The proposal further addresses the properties of isotopically pure germanium nano-crystals. Selective Neutron Transmutation Doping (NTD) will be used to form acceptors (70Ge) or donors (74Ge). The NTD process looks promising because it occurs at temperatures sufficiently low for the newly formed dopant atoms to remain inside the nanocrystal. Choice of the isotopic composition also allows selection of isotopes with or without nuclear spin. Semiconductors with controlled nuclear spin distribution are of great current interest to the rapidly emerging field of "spintronics." The proposed research offers graduate and undergraduate students training in cutting-edge research in several fields of science and technology.This project addresses (1) the study of diffusion in crystalline thin film multilayer structures and (2) the properties of nano-particles composed of enriched isotopes of the semiconductor elements silicon and germanium. Atom self-diffusion and dopant diffusion are used in several of the key processes used to fabricate modern semiconductor devices ("chips"). The present studies are designed to reveal the atomic-level diffusion mechanisms in mixtures of silicon and germanium. The results will expand the fundamental solid-state knowledge base, and may lead to the discovery of new diffusion processes. The latter will be of direct use to the designers of future very high-speed electronic devices. The proposal further addresses the properties of isotopically pure germanium nano-crystals that have been doped using selective nuclear techniques. Choice of the isotopic composition also allows selection of isotopes with nuclear spin that are of great current interest to the rapidly emerging field of "spintronics." The proposed research offers graduate and undergraduate students training in cutting-edge research in several fields of science and technology.

本研究课题主要研究（1）结晶薄膜多层结构中原子扩散的物理学;（2）由同位素控制的半导体构成的纳米粒子的性质。自扩散（即，同位素互扩散）和掺杂剂扩散将首次在应变和弛豫硅锗（SiGe）多层结构中直接并同时进行研究。这些研究旨在揭示各种扩散机制的物理基础。预期的结果将扩大基本的固态知识基础，可能会导致新的扩散过程的发现，并将直接用于未来的SiGe电子器件的设计者。该提案进一步解决了同位素纯锗纳米晶体的性质。选择性中子嬗变掺杂（NTD）将用于形成受体（70 Ge）或供体（74 Ge）。NTD工艺看起来很有前途，因为它发生在足够低的温度下，新形成的掺杂剂原子可以留在晶体内部。同位素组成的选择还允许选择具有或不具有核自旋的同位素。具有可控核自旋分布的半导体是当前迅速兴起的“自旋电子学”领域的一大兴趣。“本研究计划为研究生和本科生提供多个科学技术领域的前沿研究培训。本项目涉及（1）结晶薄膜多层结构中的扩散研究;（2）由半导体元素硅和锗的浓缩同位素组成的纳米粒子的性质。原子自扩散和掺杂剂扩散用于制造现代半导体器件（“芯片”）的几个关键工艺中。本研究旨在揭示硅和锗混合物中原子级的扩散机制。结果将扩大基本的固态知识库，并可能导致新的扩散过程的发现。后者将直接用于未来超高速电子设备的设计者。 该提案还涉及使用选择性核技术掺杂的同位素纯锗纳米晶体的性质。同位素组成的选择也允许选择具有核自旋的同位素，这对迅速兴起的“自旋电子学”领域具有很大的现实意义。“拟议中的研究为研究生和本科生提供了几个科学和技术领域前沿研究的培训。