Integrated GaN-Diamond Microwave Electronics: From Materials, Transistors to MMICs

集成 GaN-金刚石微波电子器件：从材料、晶体管到 MMIC

• 批准号: EP/P00945X/1
• 负责人: Martin Kuball
• 金额: $ 551.14万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FP00945X%2F1
• 关键词: Integrated; GaN; Diamond; Microwave; Electronics

Global demand for high power microwave electronic devices that can deliver power densities well exceeding current technology is increasing. In particular Gallium Nitride (GaN) based high electron mobility transistors (HEMTs) are a key enabling technology for high-efficiency military and civilian microwave systems, and increasingly for power conditioning applications in the low carbon economy. This material and device system well exceeds the performance permitted by the existing Si LDMOS, GaAs PHEMT or HBT technologies. GaN-based HEMTs have reached RF power levels up to 40 W/mm, and at frequencies exceeding 300 GHz, i.e., a spectacular performance enabling disruptive changes for many system applications. However, transistor reliability is driven by electric field and channel temperature, so self-heating means in practice that reliable devices can only be operated up to RF power densities of 10 W/mm in contrast to the 40 W/mm hero data published in the literature. Considerable concern also exists in the UK and across Europe that access to state-of-the-art GaN microwave technology is limited by US ITAR (International Traffic in Arms Regulation) restrictions. The most advanced capabilities for all elements of GaN HEMT technology, using traditional SiC substrates, epitaxy and device processing currently reside in the US, with restricted access by UK industry.The vision of Integrated GaN-Diamond Microwave Electronics: From Materials, Transistors to MMICs (GaN-DaME) is to develop transformative GaN-on-Diamond HEMTs and MMICs, the technology step beyond GaN-on-SiC, which will revolutionize the thermal management which presently limits GaN electronics. Challenges occur in terms of how to integrate such dissimilar materials into a reliable device technology. The outcome will be devices with a >5x increase in RF power compared to GaN-on-SiC, or alternatively and equally valuably, a dramatic 'step-change' shrinkage in MMIC or PA size, and hence an increase in efficiency through the removal of lossy combining networks as well as a reduction in power amplifier (PA) cost. This represents a disruptive change in capability that will allow the realisation of new system architectures e.g. for RF seekers and medical applications, and enable the bandwidths needed to deliver 5G and beyond. Reduced requirements for cooling / increased reliability will result in major cost savings at the system level. To enable our vision to become reality, we will develop new diamond growth approaches that maximize diamond thermal conductivity close to the active GaN device area. In present GaN-on-Diamond devices a thin dielectric layer is required on the GaN surface to enable seeding and successful deposition of diamond onto the GaN. Unfortunately, most of the thermal barrier in these devices then exists at this GaN-dielectric-diamond interface, which has much poorer thermal conductivity than desired. Any reduction in this thermal resistance, either by removing the need for a dielectric seeding layer for diamond growth, or by optimizing the grain structure of the diamond near the seeding, would be of huge benefit. Novel diamond growth will be combined with innovative micro-fluidics using phase-change materials, a dramatically more powerful approach than conventional micro-fluidics, to further aid heat extraction. An undiscussed consequence of using diamond, its low dielectric constant, which poses challenges and opportunities for microwave design will be exploited. At the most basic level, the reliability of this technology is not known. For instance, at the materials level the diamond and GaN have very different coefficients of thermal expansion (CTE). Mechanically rigid interfaces will need to be developed including interdigitated GaN-diamond interfaces.

全球对高功率微波电子器件的需求正在增加，这种器件可以提供远远超过当前技术的功率密度。特别是基于氮化镓（GaN）的高电子迁移率晶体管（hemt）是高效军用和民用微波系统的关键使能技术，并且越来越多地用于低碳经济中的功率调节应用。这种材料和器件系统的性能远远超过了现有的Si LDMOS， GaAs PHEMT或HBT技术所允许的性能。基于氮化镓的hemt已经达到了高达40 W/mm的射频功率水平，频率超过300 GHz，也就是说，这是一种惊人的性能，可以为许多系统应用带来颠覆性的变化。然而，晶体管的可靠性是由电场和通道温度驱动的，因此自热意味着在实践中，可靠的器件只能在10 W/mm的射频功率密度下工作，而不是文献中发表的40 W/mm的hero数据。在英国和整个欧洲也存在相当大的担忧，即获得最先进的氮化镓微波技术受到美国ITAR（国际武器贸易条例）限制。目前，使用传统SiC衬底、外延和器件加工的GaN HEMT技术所有元素的最先进能力都在美国，英国工业界的准入受到限制。集成GaN-金刚石微波电子：从材料，晶体管到mmic （GaN- dame）的愿景是开发变革性GaN-on-金刚石hemt和mmic，这一技术超越了GaN-on- sic，这将彻底改变目前限制GaN电子的热管理。挑战在于如何将这些不同的材料集成到可靠的设备技术中。与GaN-on-SiC相比，其结果将是射频功率增加50倍的器件，或者同样有价值的是，MMIC或PA尺寸的戏剧性“阶梯形”缩小，从而通过去除损耗组合网络提高效率，并降低功率放大器（PA）成本。这代表了能力的颠覆性变化，将允许实现新的系统架构，例如射频导引头和医疗应用，并提供提供5G及更高版本所需的带宽。降低冷却需求/提高可靠性将在系统层面上节省大量成本。为了使我们的愿景成为现实，我们将开发新的金刚石生长方法，使金刚石热导率最大化接近有源GaN器件区域。在目前的GaN-on- diamond器件中，需要在GaN表面上有一个薄的介电层，以使金刚石能够在GaN上播种和成功沉积。不幸的是，这些器件中的大多数热障存在于gan -介电-金刚石界面，其导热性比期望的要差得多。任何减少这种热阻的方法，无论是通过消除金刚石生长所需的介电播种层，还是通过优化金刚石在播种层附近的晶粒结构，都将带来巨大的好处。新型金刚石生长将与使用相变材料的创新微流体相结合，这是一种比传统微流体更强大的方法，可以进一步帮助热提取。使用金刚石的一个未讨论的后果，它的低介电常数，这对微波设计提出了挑战和机遇，将被利用。在最基本的层面上，这项技术的可靠性是未知的。例如，在材料水平上，金刚石和氮化镓具有非常不同的热膨胀系数（CTE）。需要开发机械刚性界面，包括交叉氮化镓-金刚石界面。

项目成果

Simultaneous determination of the lattice thermal conductivity and grain/grain thermal resistance in polycrystalline diamond

• DOI: 10.1016/j.actamat.2017.08.007
• 发表时间: 2017-10-15
• 期刊: ACTA MATERIALIA
• 影响因子: 9.4
• 作者: Anaya, J.;Bai, T.;Kuball, M.
• 通讯作者: Kuball, M.

Flow and heat transfer behaviour of nanofluids in microchannels

• DOI: 10.1016/j.pnsc.2018.03.005
• 发表时间: 2018-04-01
• 期刊: PROGRESS IN NATURAL SCIENCE-MATERIALS INTERNATIONAL
• 影响因子: 4.7
• 作者: Bowers, James;Cao, Hui;Ding, Yulong
• 通讯作者: Ding, Yulong

Additive GaN Solid Immersion Lenses for Enhanced Photon Extraction Efficiency from Diamond Color Centers

增材式 GaN 固体浸没透镜可提高钻石色心的光子提取效率

• DOI: 10.17863/cam.100726
• 发表时间: 2023
• 作者: Cheng X

Design Considerations of a Dual Mode X-Band EPR Resonator for Rapid In-Situ Microwave Heating

用于快速原位微波加热的双模式 X 波段 EPR 谐振器的设计考虑

• DOI: 10.1007/s00723-022-01463-1
• 发表时间: 2022
• 期刊: Applied Magnetic Resonance
• 影响因子: 1
• 作者: Barter M

Impact of stress in ICP-CVD SiN x passivation films on the leakage current in AlGaN/GaN HEMTs

ICP-CVD SiN x 钝化膜中的应力对 AlGaN/GaN HEMT 漏电流的影响

• DOI: 10.1049/el.2018.1097
• 发表时间: 2018
• 期刊: Electronics Letters
• 影响因子: 1.1
• 作者: Cho S