Scandium Nitride Crystal Growth and Characterization

氮化钪晶体生长和表征

• 批准号: 1508172
• 负责人: Placidus Amama
• 金额: $ 34.95万
• 依托单位: Kansas State 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: 2015-07-01 至 2019-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1508172&HistoricalAwards=false
• 关键词: Scandium; Nitride; Crystal; Growth; Characterization

Nontechnical Description: Scandium nitride is a semiconductor, which like silicon can be used for electronic devices, but has rarely been studied. This project focuses on making single crystals of scandium nitride that are free of defects and with low concentrations of impurities, as this is necessary for studying intrinsic properties of this material and determining its potential for future device applications such as light emitting diodes and high-temperature electronics. Scandium nitride crystals have been difficult to produce because of its very high melting temperatures. The crystal growth method used in this research, physical vapor transport, produces larger, better quality scandium nitride crystals than previously employed methods. Graduate students supported by this project are receiving hands-on research training while making new scientific discoveries and developing new technologies. This project also introduces young women (12 to 14 years old) to the science and technology of crystal growth and semiconductors, through the K-State Girls Researching Our World summer workshops. Technical Description: Single crystals of scandium nitride (ScN) with no or significantly fewer defects are grown to explore the intrinsic electrical properties of this semiconductor. To achieve this goal, the specific activities of the research are as follows. First, the process of crystal growth by physical vapor transport is optimized by adjusting the furnace temperature, pressure, and configuration to produce material with low defect densities and low impurity concentrations. These experiments are guided by thermodynamic and transport phenomena modeling. Second, the electrical properties of ScN are measured and correlated with the temperature and impurity concentrations, to reveal its electrical conduction energetics. Specifically, the electron mobility and charge carrier concentrations are determined by temperature-dependent Hall effect measurements and are correlated with the crystal defect densities (determined by defect sensitive etching), deviations from stoichiometry, and impurity concentrations (measured by secondary ion mass spectrometry). Third, selected impurities are intentionally added to scandium nitride to determine how they change its electrical properties. Differences in the properties caused by the crystal orientation and polarity (nitrogen or scandium) are investigated. By correlating these measurements with the process conditions, methods of controlling ScN's electrical properties are under development. This study provides valuable intrinsic electrical properties of ScN for future device explorations.

非技术描述：氮化钪是一种半导体，它像硅一样可以用于电子设备，但很少被研究。该项目的重点是制造无缺陷和低浓度杂质的氮化钪单晶，因为这对于研究这种材料的固有特性和确定其未来器件应用（如发光二极管和高温电子器件）的潜力是必要的。氮化钪晶体由于其非常高的熔化温度而难以生产。在这项研究中使用的晶体生长方法，物理气相传输，产生更大，更好的质量比以前采用的方法的氮化钪晶体。 该项目支持的研究生在进行新的科学发现和开发新技术的同时接受实践研究培训。该项目还通过K州女孩研究我们的世界暑期讲习班，向年轻妇女（12至14岁）介绍晶体生长和半导体科学技术。技术说明：生长没有缺陷或缺陷明显较少的氮化钪（ScN）单晶，以探索这种半导体的固有电性能。为实现这一目标，研究的具体活动如下。首先，通过调节炉的温度、压力和配置来优化通过物理气相传输的晶体生长过程，以产生具有低缺陷密度和低杂质浓度的材料。这些实验是由热力学和运输现象建模。其次，测量了ScN的电学性质，并与温度和杂质浓度进行了关联，以揭示其导电能量学。具体来说，电子迁移率和电荷载流子浓度由温度相关霍尔效应测量确定，并与晶体缺陷密度（通过缺陷敏感蚀刻确定）、化学计量偏差和杂质浓度（通过二次离子质谱法测量）相关。第三，故意将选定的杂质添加到氮化钪中，以确定它们如何改变其电特性。晶体取向和极性（氮或钪）所造成的性质的差异进行了研究。通过将这些测量与工艺条件相关联，控制SCN的电性能的方法正在开发中。这项研究提供了宝贵的内在的电性能的SCN为未来的设备探索。