Uniaxial and Hydrostatic Stress on Group III-nitride Heterojunctions and Schottky Barriers

III 族氮化物异质结和肖特基势垒的单轴应力和静水应力

• 批准号: 0140164
• 负责人: Marshall Nathan
• 金额: $ 22.5万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-05-15 至 2006-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0140164&HistoricalAwards=false
• 关键词: Uniaxial; Hydrostatic; Stress; Group; III

Abstract-0140164M. Nathan, U of Minnesota-Twin CitiesDevices based on III-nitride semiconductors have great potential for many applications in optoelectronics and power electronics. Polarization effects in these materials provide new opportunities for new device designs and raise challenges for existing ones. At present, while a qualitative understanding of these effects exists to some extent, a complete quantitative model and experimental characterization is lacking. The main thrust of this proposal is directed at a quantitative understanding of polarization effects in III-nitride compounds.Polarization effects and nitride-based devices are inextricably connected with dominant effects in heterojunction FETs, heterojunction bipolar transistors, and lasers. Consideration of spontaneous and piezoelectric effects is therefore imperative in device design. In addition to high-power, high-temperature electronic devices, we envision possible applications of these phenomena in stress (or force) sensors, such as those needed for accelerometers and seismic detectors intended to operate in caustic environments.We propose a coordinated experimental and theoretical investigation of electric polarization effects in III-nitride heterostructures and Schottkv barriers. Our study will address lattice polarization effects on charge carrier transport at heterojunction interfaces in structures with currents either parallel or perpendicular to the interfaces. Examples of structures to be fabricated and tested will include n- and p-channel single heterostructures, metal/semiconductor Schottky contacts on III-nitrides, and n+- and p+Si/III-nitride Schottky contacts. To avoid possible surface contamination, Al/III-nitride and Si/III-nitride contacts will be fabricated in situ, i.e. without removing the samples from the ultra-high vacuum environment. For reasons discussed in this proposal, we view these latter structures (with the non-polar/polar interface grown in situ following III-nitride epitaxy) as particularly promising for the study of III-nitride surface polarization charges. We will measure the uniaxial and hydrostatic stress dependences of the electrical characteristics of these structures. Exploring different stress geometries will advance the understanding of piezoelectric effects in III-nitride compounds. Our physical model development will address band structure and electric polarization effects and their consequences for the terminal characteristics of the devices under uniform and non-uniform, uniaxial and hydrostatic stress. The characterization and modeling work builds on capabilities developed by the PIs over the last 11 years in the context of their past and ongoing joint exploration of piezoelectric effects in conventional III-V heterostructures. The crystal growth for this program will performed by Professor Hadis Morkoq's group at Virginia Commonwealth University.The proposed research will involve both graduate and undergraduate students, and will enhance the PIs ongoing course development with focus on large gap semiconductor materials and devices.

摘要-0140164M。基于III-硝酸盐半导体的明尼苏达州二人城市的Nathan对于光电和电力电子中的许多应用都有很大的潜力。这些材料的极化效应为新设备设计提供了新的机会，并为现有材料带来了挑战。目前，虽然对这些影响的定性理解在某种程度上存在，但缺乏完整的定量模型和实验表征。该提案的主要目的是对III氮化物化合物中极化效应的定量理解。极化效应和基于氮化物的设备与异质结FET，异性结双极晶体管和激光器的异质结FET中的显着作用无关。因此，在设备设计中必须考虑自发和压电效应。除了高功率，高温电子设备外，我们还设想了这些现象在压力（或力）传感器中的可能应用，例如，加速度计和地震探测器所需的应用程序，目的是在速度环境中运行。我们提出了对IIIII-Nitride ossostreser和Schotterers schottkntress and Schottktkvvirers ofertical Electricallization效应的协调实验和理论研究。我们的研究将解决与界面平行或垂直于界面的结构中的异质结界面的电荷载体传输的晶格极化效应。要制造和测试的结构的示例将包括N二硝酸盐上的N型和P通道单个异质结构，金属/半导体Schottky接触，以及N+ - 以及P+SI/III-Nitride Schottky接触。为避免可能的表面污染，将原位制造Al/iii-nitride和Si/III氮化物接触，即不清除超高真空环境中的样品。出于本提案中讨论的原因，我们认为这些后一种结构（具有III二硝酸盐外延后原位生长的非极性/极性界面）对于研究III硝酸盐表面极化电荷的研究特别有希望。我们将测量这些结构的电特性的单轴和静液压应力依赖性。探索不同的压力几何形状将提高对III硝酸化合物中压电效应的理解。我们的物理模型的发展将解决带的结构和电化效应及其对设备在均匀和不均匀，单轴和静水压力下的终端特征的后果。在过去的11年中，PIS在过去的11年中以及对传统III-V异质结构中的压电效应的持续共同探索的背景下，表征和建模工作建立在过去的11年中。该计划的水晶增长将由Hadis Morkoq教授在弗吉尼亚联邦大学进行。拟议的研究将涉及研究生和本科生，并将以大型间隙半导体材料和设备的重点增强PIS持续的课程开发。