Traps in MBE-grown III-Nitride FET Structures on SiC

SiC 上 MBE 生长的 III 族氮化物 FET 结构中的陷阱

• 批准号: 0330226
• 负责人: Mulpuri Rao
• 金额: $ 22.5万
• 依托单位: George Mason University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-09-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0330226&HistoricalAwards=false
• 关键词: Traps; MBE; grown; III; Nitride

Intellectual Merit: A lack of sufficient knowledge on traps, which are present in bulk, at surface, and at heterojunction interfaces is one of the main obstacles for the progress of high-power III-nitride compound semiconductor microwave devices. The proposed basic research is aimed at identifying the traps (i.e. finding their energy in the bandgap with respect to a band edge, their capture cross-section and origin), which profoundly effect the device characteristics such as: drain current collapse, gain compression, gate and drain lag, frequency dispersion of transconductance and drain conductance of MBE-grown III-nitride GaN MESFETs, AlGaN/GaN HEMTs, and AlInGaN/InGaN HEMTs. Identification of traps in these device structures is very important for optimizing the device design, growth, and processing conditions and consequently for maximizing high-power microwave performance. The AlInGaN/InGaN HEMTs are projected to yield record power performance once their design, growth, and processing conditions are optimized. A series of sets of samples will be fabricated, with only one growth/processing condition (growth temperature, surface passivation etc.) or a device design feature (alloy composition, layer thickness etc.) varied in each set keeping all the remaining conditions same. All devices will be characterized first for their DC, and pulsed drain current-drain voltage-gate voltage performance including the gate-lag and drain-lag; output power, gain and power added efficiency performance as a function of input power at various bias conditions and frequencies; and then for traps in the device structure. The traps will be studied by drain-current and gate capacitance deep level transient spectroscopy, photoionization spectroscopy, and transconductance and output-admittance frequency dispersion measurements. Energy location of the traps with respect to the band edges, their capture cross-section and concentration will be determined by analyzing the experimental data. Trap measurements also will be performed on devices subjected to short and long-term bias stress. For each set of samples the device performance and trap measurements results, and the extent of change in growth/processing/design parameter in that set of samples will be correlated to identify the trap/traps responsible for deterioration of a specific device performance quantity; origin of the trap/traps; and the growth, processing and design conditions, which can minimize the trap concentration. Broader Impacts: The proposed work is a careful, detailed basic research, which requires careful experimentation and analysis. Results of this work will have an immediate impact on advancing high-power microwave III-nitride compound semiconductor device technology, by providing optimum growth and processing conditions, and device design features required for obtaining maximum device performance. This work will be performed in collaboration with III-nitride device research group at Naval Research Laboratory (NRL). The PI has been successfully collaborating with NRL scientists, for more than 15 years, on NSF supported projects. This project offers an excellent opportunity for students for gaining hands-on experience on using state-of-the-art device growth, processing and characterization equipment in a prestigious government laboratory on an important research topic. This experience prepares students well for pursuing careers in industry and government. Both graduate and undergraduate students will participate on the proposed research.

智力优势：缺乏足够的知识陷阱，这是存在于体，在表面上，并在异质结界面的主要障碍之一，为高功率III族氮化物半导体微波器件的进展。提出的基础研究的目的是确定陷阱（即找到他们的能量在带隙相对于一个带边，他们的捕获截面和起源），这深刻影响的器件特性，如：漏电流崩溃，增益压缩，栅极和漏极滞后，频率色散的GaN MESFETs，AlGaN/GaN HEMT，和AlInGaN/InGaN HEMT的漏极电导。 识别这些器件结构中的陷阱对于优化器件设计、生长和加工条件以及因此最大化高功率微波性能是非常重要的。一旦设计、生长和工艺条件得到优化，AlInGaN/InGaN HEMT预计将产生创纪录的功率性能。将制造一系列样品组，只有一种生长/处理条件（生长温度、表面钝化等）。或器件设计特征（合金成分、层厚度等）在每组中变化，保持所有其余条件相同。所有器件将首先表征其DC和脉冲漏极电流-漏极电压-栅极电压性能，包括栅极滞后和漏极滞后;在各种偏置条件和频率下，输出功率、增益和功率附加效率性能作为输入功率的函数;然后表征器件结构中的陷阱。陷阱将被研究的漏极电流和栅极电容深能级瞬态谱，光电离谱，和介电常数和输出导纳频散测量。陷阱相对于能带边缘的能量位置，它们的捕获截面和浓度将通过分析实验数据来确定。还将对受到短期和长期偏置应力的器件进行陷阱测量。对于每组样品，器件性能和陷阱测量结果以及该组样品中生长/处理/设计参数的变化程度将被关联，以识别导致特定器件性能量劣化的陷阱;陷阱的来源;以及生长、处理和设计条件，其可以最小化陷阱浓度。更广泛的影响：拟议的工作是一项仔细，详细的基础研究，需要仔细的实验和分析。这项工作的结果将有一个直接的影响，推进高功率微波III族氮化物化合物半导体器件技术，通过提供最佳的生长和加工条件，并获得最大的器件性能所需的器件设计功能。 这项工作将与海军研究实验室（NRL）的III族氮化物器件研究小组合作进行。PI与NRL科学家在NSF支持的项目上成功合作超过15年。该项目为学生提供了一个绝佳的机会，可以在著名的政府实验室中就重要的研究课题使用最先进的器件生长、加工和表征设备获得实践经验。这种经验为学生在工业和政府领域从事职业做好了准备。研究生和本科生都将参加拟议的研究。