EPSRC-SFI Aluminium-Rich Nitride Electronics (ARNE)

宽带隙(WBG)半导体提供了提供电子设备和系统的潜力，其先进的功率处理性能超过了硅。这源于它们固有的在较高电压下工作的能力，这归因于它们较大的半导体带隙。尽管WBG技术GaN和SiC的发展取得了很大的进展，但具有更大禁带宽度的新型和新兴材料(所谓的超宽带隙半导体)提供了更大的潜在性能收益。最大限度地提高这类电子元件的高功率处理能力，对于解决我们目前面临的许多与能源和环境有关的挑战至关重要。例如，需要先进的高功率固态系统来实现智能电网，以实现未来的电力分配和电动汽车的高效电压转换。为了满足未来通信(如Beyond 6G移动通信)和雷达系统的性能要求，还需要运行在高频下的高功率系统。AlGaN是一种新兴的超宽带隙(UWBG)材料，具有在低频率和毫米波频率下提供比现有WBG半导体技术更出色的高功率处理的潜力，同时关键是提供与基本上成熟的GaN材料平台的集成潜力。与GaN相比，铝的引入大大增加了AlGaN的带隙，从而大大增加了击穿电场，甚至可以为更高的Al组分提供更高电压的器件。然而，将本征材料从绝缘体转变为半导体所需的AlGaN掺杂比GaN更具挑战性，特别是对于较高的Al组分。然而，利用与GaN器件技术中使用的极化诱导掺杂技术类似的技术，可能会产生一条途径，实现这种材料系统在下一代大功率电子应用中的巨大潜力。在这项工作中，我们将开展材料调查和评估研究，通过材料模拟、设计、生长和表征计划，评估和绘制Al含量为50%到100%的AlGaN外延层的关键物理和电子材料性能(从而可以实现GaN以外的高功率器件操作潜力的最大好处)。这项初步的材料研究将与使用这些材料中最有前途的材料层的场效应晶体管器件的开发相结合并加以补充，以展示初步的器件性能潜力。本研究的结果将用于：i)评估富铝AlGaN的潜力，重点放在高功率射频器件应用上；ii)确定为实现这一高功率和射频功率应用的潜力需要解决的技术挑战；iii)为英国和爱尔兰学术界和工业界建立持续的富铝AlGaN技术研究和开发战略。

Wide bandgap (WBG) semiconductors offer the potential to deliver electronic devices and systems with advanced power handling performance beyond that achievable in silicon. This stems from their intrinsic ability to operate at higher voltages, as attributed to their larger semiconductor bandgap. Although excellent progress has been made in the development of WBG technologies GaN and SiC, new and emerging materials with even larger bandgap (so called ultra-wide bandgap semiconductors) offer even greater potential performance gains. Maximising the high-power handling capability of such electronic components is essential to address many of the energy and environmental-related challenges that we currently face. For instance, advanced high-power solid-state systems will be required to enable smart power grids for future distribution of electricity and for efficient voltage conversion in electric vehicles. High power systems operating at high frequencies will also be required to meet the performance demands of future communication (e.g. beyond 6G mobile comms) and radar systems. AlGaN is an emerging ultra-wide bandgap (UWBG) material with the potential to deliver superior high-power handling at both low and millimetre wave frequencies than existing WBG semiconductor technologies, while crucially providing integration potential with the largely mature GaN material platform. In contrast to GaN, the introduction of aluminium to produce AlGaN increases the bandgap substantially, allowing for greatly increased breakdown field and even higher-voltage device operation for a higher Al composition. Doping of AlGaN, as required to convert the intrinsic material from an insulator into a semiconductor, is significantly more challenging than GaN however, particularly for higher Al compositions. Exploitation of polarisation-induced doping techniques similar to that used in GaN device technologies may however yield a route to realise the large potential of this material system for next generation high power electronic applications. In this work we will undertake a material investigation and evaluation study to assess and map crucial physical and electronic material properties for AlGaN epitaxial layers with 50% to 100% Al content (whereby the most benefit in terms of high-power device operation potential beyond GaN may be achieved), through a programme of material simulation, design, growth and characterisation. This initial material study will be coupled with and complemented by the development of Field Effect Transistor devices using the most promising of these material layers to demonstrate preliminary device performance potential. The outcomes of this study will be used to i) evaluate the potential of Al-rich AlGaN with a focus on high power RF device applications, ii) identify the technical challenges that need to be addressed to realise this potential for both high power and RF power applications iii) establish an ongoing research and exploitation strategy for UK and Irish academia and industry for Al-rich AlGaN-based technology.