Laser lifted off III-Nitride and GaN circuits to enable next generation chargers, electric vehicle drives, and wearable electronics

激光剥离 III 族氮化物和 GaN 电路，以实现下一代充电器、电动汽车驱动器和可穿戴电子产品

• 批准号: 2246582
• 负责人: MVS Chandrashekhar
• 金额: $ 50万
• 依托单位: University of South Carolina at Columbia
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-08-15 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2246582&HistoricalAwards=false
• 关键词: Laser; lifted; off; III; Nitride

AlxGa1-xN semiconductors have extreme properties such as high heat removal, high temperature operation, and high current/voltage handling that are ideal for high power compact electronics in electric vehicles. These extreme properties make them excellent for low power applications such as wearables beyond traditional silicon as validated by the emergence of GaN chargers in consumer electronics. Further scaling of device performance with Al content is currently limited by the wafers on which AlxGa1-xN active layer coatings are produced. By removing the wafer and transferring ultrathin active coatings to application specific engineered surfaces, can the full promise of AlGaN’s superior properties be realized in ultra-compact devices? This question will be answered using a patent pending laser liftoff (LLO) AlGaN transfer developed by our team to remove the growth wafer. If successful, our work would transform power transistors for electric vehicles and power grid applications and could lead to the first practical wearable III-Nitride devices from this Nobel winning material system that led to the 2014 Physics prize for the blue LED. Part of this work will be performed by Engineering undergraduates in collaboration with the nation’s best department of Exercise Science and could enable tech transfer of what could be the first application of flexible III-N in healthcare.This work will be performed in the following 3 thrusts.1. Characterizing steady state and transient thermal performance of AlGaN channel transistors by transferring/soldering to Cu heat sinks. This will eliminate the series thermal/electrical resistances of the substrate, reducing thermal time constants from the ms range to the us range. These are suitable for kHz-MHz switching applications without significant temperature rise, a crucial requirement in deep-scaled power electronics that can reach the ideal performance codified in the Baliga Figure of merit.2. Piezoelectric sensing on flexible substrates by transferring depletion mode high-electron mobility transistors (HEMTs) to flexible polyethylene terephthalate (PET). By flexing the AlGaN heterojunction, piezoelectric charge in the channel changes, an effect amplified by the transistor Given the ~1A/mm drive we have obtained for LLO transferred AlGaN/GaN transistors, and PET’s known high critical breakdown field 5MV/cm, we enable new functionalities previously not possible in flexible electronics. We will mount this device on human participants to evaluate the viability of wearable III-N heart rate sensors as a piezoelectric stethoscope.3. Integration of visible III-N emitters and photodetectors in a single package using a LLO pick and place approach to demonstrate a flexible III-N photonic circuit. This will be used to develop an understanding of bandwidth limiting defects induced by LLO and packaging in low-leakage circuits. Defect studies will also inform the other case studies to determine the ultimate bandwidth and power handling capabilities of AlGaN devices. A key issue is that of strain relief induced damage from the highly traumatic laser liftoff and transfer process. This is a problem that we have minimized through our preliminary enabling research, although it is a key problem that will limit the viability of this technology.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.

ALXGA1-XN半导体具有极端的特性，例如高热量，高温操作和高电流/电压处理，非常适合电动汽车中高功率紧凑的电子设备。这些极端特性使它们非常适合低功率应用，例如通过消费电子中GAN充电器出现的传统硅之外的可穿戴设备。目前，用Al内容进一步缩放设备性能的限制受生产ALXGA1-XN活动层涂层的波。通过删除摇动并将超薄活性涂层转移到应用特定工程表面上，可以在超紧凑型设备中实现Algan出色特性的全部承诺吗？该问题将使用悬而未决的激光升降（LLO）Algan转移到我们团队开发以消除增长动摇的情况下回答这个问题。如果成功的话，我们的工作将改变电动汽车和电网应用的电源变压器，并可能导致该诺贝尔奖赢得材料系统的第一个可实用的可穿戴III氮化物设备，从而获得了2014年蓝色LED物理奖。这项工作的一部分将由工程大学本科生与美国最佳运动科学系合作进行，并可以使技术转移能够在医疗保健中首次应用。这项工作将在以下3个推力中进行。1。通过将/焊接转移到Cu散热器上来表征Algan通道晶体管的稳态和瞬态热性能。这将消除基板的串联热/电阻，从而将热时间常数从MS范围降低到美国范围。这些适用于无明显温度升高的KHz-MHz切换应用，这是深度缩放的电力电子设备的关键要求，可以达到绩效Baliga图中所审查的理想性能。2。通过将部署模式高电子迁移率晶体管（HEMT）转移到柔性聚对苯二甲酸酯（PET），对柔性底物的压电灵敏度。通过弯曲Algan的杂结期，通道变化中的压电电荷，鉴于我们为LLO传输的Algan/Gan晶体管获得的〜1A/mm驱动器所扩增的效果，以及PET已知的高关键击穿场5MV/CM，我们以前无法在灵活的电子中启用新功能。我们将将此设备安装在人类参与者上，以评估可穿戴III-N心率传感器作为压电性听觉仪的生存能力3。使用LLO拾音器和位置方法在单个包装中的可见iii-n发射器和光电电视器的整合，以演示灵活的III-N光子电路。这将用于建立对LLO和低卵形电路包装引起的带宽限制缺陷的理解。缺陷研究还将告知其他案例研究，以确定Algan设备的最终带宽和功率处理能力。一个关键问题是应变缓解引起的高度创伤性激光升高和转移过程的损害。这个问题是我们通过初步促进研究最大程度地降低的，尽管这是一个关键问题，它将限制该技术的可行性。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛影响的审查标准通过评估而被视为珍贵的支持。