CAREER: Engineering Ultra-Wide Bandgap III-Nitride Devices for Highly Efficient and Robust Electronics

职业：设计超宽带隙 III 族氮化物器件，实现高效、稳健的电子产品

• 批准号: 2145340
• 负责人: Spyridon Pavlidis
• 金额: $ 50万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2145340&HistoricalAwards=false
• 关键词: CAREER; Engineering; Ultra; Wide; Bandgap

The global demand for energy will likely significantly increase in the coming decades as more of the world gains access to electricity. This demand will need to be met without intensifying existing concerns over the environmental, societal, and economic impacts of climate change, which is influenced by the efficiency of power systems. Furthermore, since this efficiency is tied to losses associated with the semiconductor devices used in power electronics, the replacement of today’s silicon-based components with a novel semiconductor technology must be investigated. Wide bandgap semiconductors are candidates, however ultra-wide bandgap (UWBG) semiconductors represent the next frontier. In particular, aluminum-rich aluminum gallium nitride (AlGaN) offers an exciting opportunity to explore a new generation of highly efficient and robust electronic devices. The robustness of these devices in the face of elevated temperatures or electromagnetic interference (EMI) also stands to improve system performance and reliability. Thus far, a combination of unresolved scientific questions and technological barriers have prevented AlGaN devices from reaching their full potential. The recent commercialization of aluminum nitride (AlN) wafers, however, permits the ideal properties of AlGaN films to be studied for the first time. Thus, the research objective of this CAREER project is to understand the operational physics of high voltage AlGaN devices and develop engineering solutions that will unlock their performance for power electronics where efficiency and robustness are key. The investigator is also committed to becoming a leading educator in the area of semiconductor devices via the use of team-based, laboratory-based methods and is passionate about ensuring equal access to STEM education/training. Three education/outreach tasks have been defined with the objectives of: (1) equipping undergraduates with marketable skills via hands-on research experiences that they can leverage for STEM careers, (2) engaging underrepresented minority groups to diversify the STEM workforce, and (3) increasing the public’s scientific literacy surrounding semiconductors/electronics.The objective of this CAREER project is to understand the performance limits of ultra-wide bandgap AlGaN-based power devices and establish solutions to deploy these devices in highly efficient and robust systems. The potential for Al-rich AlGaN to support large electric fields will be understood by experimentally extracting the impact ionization coefficients from avalanche photodiodes realized on native AlN substrates. The results will be used to minimize the drift region’s contribution to the overall conduction loss. Since low resistance ohmic contacts to Al-rich AlGaN remain elusive, the surfaces and bulk of UWBG AlGaN will be engineered to obtain thermally stable contacts with reduced contact resistance. The surface barrier height will be reduced using both ex-situ and in-situ interlayers that compensate AlGaN’s polarization charge. Tunneling contacts will also be sought by heavily doping the bulk AlGaN via Si implantation followed by effective activation annealing. The limits of high temperature operation will be explored. Next, p-type doping of AlGaN, in particular for buried and lateral regions, is a barrier towards advanced power devices. Thus, novel Crystal Heterogeneous Integration (CHI) will be investigated to combine p-type compound semiconductors with n-type AlGaN. The high voltage breakdown of heterogeneous PN junctions will be evaluated, as well as their response to light to interpret the resulting band structures and explore carrier transport across the junction. These research tasks will be leveraged to design, fabricate, and characterize high voltage (1-5 kV) AlGaN diodes, with a view to demonstrating the promise of AlGaN technology in future power systems. Their stability in the face of high temperature exposure will also be examined. To address the risk of EMI, the first phototransistor that heterogeneously integrates AlGaN with other compound semiconductors will be investigated for fast optical gating and high voltage blocking.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

随着世界上更多的地方获得电力，未来几十年全球能源需求可能会大幅增加。这一需求需要在不加剧现有对气候变化的环境、社会和经济影响的担忧的情况下得到满足，这些影响受到电力系统效率的影响。此外，由于这种效率与电力电子中使用的半导体器件相关的损耗有关，因此必须研究用新的半导体技术取代当今的硅基元件。宽带隙半导体是候选者，然而超宽带隙（UWBG）半导体代表下一个前沿。特别是，富铝的氮化铝镓（AlGaN）提供了一个令人兴奋的机会，探索新一代的高效和强大的电子器件。这些器件在面对高温或电磁干扰（EMI）时的鲁棒性也有助于提高系统性能和可靠性。到目前为止，尚未解决的科学问题和技术障碍阻碍了AlGaN器件充分发挥其潜力。然而，最近的商业化氮化铝（AlN）晶片，允许AlGaN薄膜的理想性能进行研究的第一次。因此，该CAREER项目的研究目标是了解高压AlGaN器件的操作物理学，并开发工程解决方案，以释放其在电力电子领域的性能，其中效率和鲁棒性是关键。调查员还致力于通过使用基于团队，基于实验室的方法成为半导体器件领域的领先教育者，并热衷于确保平等获得STEM教育/培训。确定了三项教育/外联任务，其目标是：（1）通过实践研究经验为本科生提供可用于STEM职业的市场技能，（2）让代表性不足的少数群体参与STEM劳动力的多样化，（3）提高公众对半导体的科学素养;这个CAREER项目的目标是了解超宽带隙AlGaN基功率器件的性能限制，并建立解决方案，以在高效和强大的系统中部署这些器件。富铝AlGaN支持大电场的潜力将被理解通过实验提取的冲击电离系数从雪崩光电二极管上实现原生AlN基板。结果将用于最大限度地减少漂移区的整体传导损失的贡献。由于与富铝AlGaN的低电阻欧姆接触仍然难以实现，因此UWBG AlGaN的表面和本体将被设计成获得具有降低的接触电阻的热稳定接触。使用非原位和原位中间层来补偿AlGaN的极化电荷，将降低表面势垒高度。还将通过经由Si注入重掺杂体AlGaN，然后进行有效的激活退火来寻求Tunnel接触。将探索高温操作的极限。其次，AlGaN的p型掺杂，特别是对于掩埋区和横向区，是迈向先进功率器件的障碍。因此，我们将研究一种新颖的晶体异质整合（CHI）技术，以将p型化合物半导体与n型AlGaN联合收割机结合。异质PN结的高电压击穿将被评估，以及它们对光的响应，以解释由此产生的能带结构，并探索跨结的载流子输运。这些研究任务将用于设计、制造和表征高压（1-5 kV）AlGaN二极管，以展示AlGaN技术在未来电力系统中的前景。还将检查它们在高温下的稳定性。为了解决EMI的风险，将研究第一个将AlGaN与其他化合物半导体异质集成的光电晶体管，以实现快速光学选通和高压阻断。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Demonstration of near-ideal Schottky contacts to Si-doped AlN

演示与硅掺杂 AlN 的近乎理想肖特基接触

• DOI: 10.1063/5.0174524
• 发表时间: 2023
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Quiñones, C. E.;Khachariya, D.;Bagheri, P.;Reddy, P.;Mita, S.;Kirste, R.;Rathkanthiwar, S.;Tweedie, J.;Pavlidis, S.;Kohn, E.
• 通讯作者: Kohn, E.

Analysis of Vertical GaN JBS and p-n Diodes by Mg Ion Implantation and Ultrahigh-Pressure Annealing

通过镁离子注入和超高压退火分析垂直 GaN JBS 和 p-n 二极管

• DOI: 10.1109/ted.2023.3339592
• 发表时间: 2023
• 期刊: IEEE Transactions on Electron Devices
• 影响因子: 3.1
• 作者: Stein, Shane R.;Khachariya, Dolar;Mecouch, Will;Mita, Seiji;Reddy, Pramod;Tweedie, James;Sierakowski, Kacper;Kamler, Grzegorz;Bockowski, Michal;Kohn, Erhard
• 通讯作者: Kohn, Erhard

Enhancement-Mode AlInN/GaN High-Electron-Mobility Transistors Enabled by Thermally Oxidized Gates

由热氧化栅极实现的增强型 AlInN/GaN 高电子迁移率晶体管

• DOI: 10.1109/ted.2023.3343313
• 发表时间: 2023
• 期刊: IEEE transactions on electron devices
• 影响因子: 3.1
• 作者: Palmese, Elia;Xue, Haotian;Pavlidis, Spyridon;Wierer, Jonathan J.
• 通讯作者: Wierer, Jonathan J.