Interface Dipolar Engineering in III-V Semiconductors

III-V 族半导体中的界面偶极子工程

• 批准号: 9819659
• 负责人: Marshall Nathan
• 金额: $ 64万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-15 至 2003-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9819659&HistoricalAwards=false
• 关键词: Interface; Dipolar; Engineering; III; Semiconductors

This FRG (Focused Research Group) project aims for greater understanding of materials science and device physics aspects of dipole layers at heterojunction interfaces, and to modify them for improved device performance across a variety of common compound semiconductor structures: lasers, HBTs, MOSFETs, HEMTs, and Schottky barriers. The project involves theory, growth, characterization, and prototype device studies. First principle calculations will be performed by collaborators at EPFL (Switzerland), and coupled with material processing for improved device performance. Recently dual purpose molecular beam epitaxy (MBE) facilities devoted to the exploration of interface properties and the fabrication of working devices have produced tunability of band offsets and Schottky barriers through local modifications of the atomic termination of critical interfaces. In parallel with experiment, a convergence of different theoretical models, including first principles calculations, the theoretical alchemy approach and linear response theory results, are establishing a common theoretical framework. Most theoretical and experimental studies have identified heterovalent semiconductor junctions with polar orientation as those that exhibit the strongest dependence of interface properties on local interface termination. Therefore IV/III-V, II-VI/III-V, III-V/IV/III-V and III--V/II-VI/III-V interfaces may represent a class of highly tunable interface systems, as compared to the more conventional isovalent systems (e.g., III-V/III-V) where the valence difference across each interface allows fabrication of large electrostatic dipoles with orientation and magnitude largely controlled by the growth conditions.For heterojunction interfaces, parameters such as the valence and conduction band discontinuities, and the built-in potentials affect carrier confinement on both sides of the active region where radiative recombination occurs in heterojunction lasers, emitter efficiencies in HBT's, as well as the gate voltage swing and the gate leakage current in MOSFET and HEMT structures. For metal/semiconductor interfaces, present in all solid state devices, the possibility of reducing or increasing the Schottky barrier height without changing the doping of the semiconductor constituent would enhance ability to fabricate low resistivity contacts to new wide bandgap materials for which doping technology is still limited (e.g., III-V nitrides, silicon carbide, diamond), simplify the exploitation of ballistic transport in practical devices, decrease the leakage current in MESFET's, and potentially yield Schottky barrier photon detectors with tunable long -wavelength cut-off and/or lower dark currents. Thus, the project seeks to exploit heterovalency-induced, extrinsic local interface dipoles in a variety of III-V materials systems of current practical interest, including AlGaAs/GaAs, GaInAs/InP, GaInP/GaAs, and AlGaN/GaN. Different ultrathin heterovalent interlayers (e.g., Si, Ge, Si-C, Zn-O) will be fabricated by MBE to tune the band alignments as well as in related metal/semiconductor junctions. Interlayer type and growth conditions which minimize out-diffusion, and assess the range of offset tuning that can be achieved in high-quality, device grade structures will be determined. The ultimate goal is to clarify the microscopic mechanisms that determine the offset tuning while developing a series of new interfacial engineering principles for device optimization. This FRG project is co-supported by two NSF programs, and the MPS OMA(Office of Multidisciplinary Activities).%%%The project addresses basic research issues in a topical area of materials science and engineering having high potential technological relevance. The research will contribute new knowledge at a fundamental level to important fabrication aspects of electronic/photonic devices. The basic knowledge and understanding gained from the research is expected to contribute to improving the perform-ance and stability of advanced devices and circuits. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area.***

这个FRG（重点研究小组）的项目旨在对异质结界面上偶极层的材料科学和设备物理方面有更深入的了解，并将其修改为改善各种常见的复合半导体结构的设备性能：激光器，HBTS，MOSFET，HEMTS，HEMTS和SCHOTTKY屏障。该项目涉及理论，生长，表征和原型设备研究。 EPFL（瑞士）的合作者将执行第一个主要计算，并加上材料处理以改善设备性能。最近，双重目的的分子束外延（MBE）设施，用于探索界面特性和工作设备的制造，通过对关键接口的原子终止的局部修改产生了频带偏移和Schottky屏障的可调性。与实验同时，不同理论模型的融合，包括第一原理计算，理论炼金术方法和线性响应理论结果，正在建立一个共同的理论框架。大多数理论和实验研究都确定了具有极性取向的异差半导体连接，因为那些表现出界面特性对局部界面终止的依赖性最强的半导体连接。因此，IV/III-V，II-VI/III-V，III-V/III-V/III-V和III--V/II-VI/II-VI/III-V界面可能代表一类高度可调的界面系统，与更常规的等值系统相比（例如IIII-V/III-V）相比，在每个界面中均可及其范围内的每个界面的差异，并且在大型界面中允许构造较大的电位差异，并且由大量的电气构造，并且由较大的电位差异，并且可以通过构成的构造来构造，并且可以通过构造的电位差异，而构成了较大的电位差异。异质结构的接口，诸如价和传统谱带不连续性等参数以及内置电位会影响活跃区域两侧的载体限制，在该区域的两侧，在异质结激光器中发生辐射重组，HBT的发射极效率在HBT的效率下，以及闸门的电压摆动和闸门的距离和闸门泄漏和闸门的距离和闸门漏洞和闸门漏洞，并在Mostruster中泄漏。对于所有固态设备中存在的金属/半导体界面，在不改变半导体构成的掺杂的情况下，降低或增加雪花屏障高度的可能性将增强与新的宽带材料的低电阻率接触的能力，从而使掺杂技术仍然受到限制（例如，II-v nitride carbiride carbiride carbiride carbiride carbiride carbive carbive the the宽带材料，实用的设备，减少MESFET的泄漏电流，并可能产生具有可调长波长切断和/或较低深色电流的Schottky屏障光子检测器。因此，该项目试图利用各种III-V材料系统中的杂质诱导的外部局部界面偶极子，包括藻类/GAAS，Gainas/INP，Gainp/Gainp/Gaas和Algan/Gan。 MBE将制造出不同的超薄异源互层（例如Si，ge，Si-C，Zn-O），以调整带对齐方式以及相关的金属/半导体连接。将确定可以在高质量，设备等级结构中实现的偏移调整范围，并确定层间的层间类型和生长条件。最终目标是阐明在开发一系列新的界面工程原理以进行设备优化的同时确定偏移调整的微观机制。该FRG项目由两个NSF计划和国会议员OMA（多学科活动的办公室）共同支持。%%％;该项目解决了具有很高潜在技术相关性的材料科学和工程领域的基础研究问题。该研究将在基本层面上为电子/光子设备的重要制造方面提供新知识。从研究中获得的基本知识和理解力有望有助于提高高级设备和电路的性能和稳定性。 该计划的一个重要特征是通过培训学生在根本和技术意义的领域中培训研究和教育。***