TESiC-SuperJ - Trench Epitaxy for SiC Superjunctions: technology enabling low loss HVDC power electronics.

TESiC-SuperJ - SiC 超级结的沟槽外延：实现低损耗 HVDC 电力电子设备的技术。

• 批准号: EP/W004291/1
• 负责人: Vishal Ajit Shah
• 金额: $ 50.82万
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW004291%2F1
• 关键词: TESiC; SuperJ; Trench; Epitaxy; SiC

In 2019 48.5% of the 32 GW daily average energy demand in the UK was carbon-free - contributed by wind farms, solar and nuclear energy, alongside energy imported by subsea interconnectors and biomass. This trend supports the "net zero" commitment signed by the government in 2019. However, significant technologies still need to be developed to enable this goal. One key such technology is high voltage direct current (HVDC) grid level transmission which will enable the "supergrid". This is a network of long distance power transmission lines across and between countries and those aforementioned energy production facilities, particularly in remote locations such as offshore wind farms. Increasing the efficiency and power rating of each grid interconnection (as well as reducing their volume and weight) it would mean more widespread implementation and hence better energy security, lower carbon footprint and better energy economy for the UK. Within most interconnectors, 50% of the volume is the power electronics devices, traditionally made from Silicon technology. Silicon Carbide (SiC) has clear advantages over current Silicon technology such as high temperature and higher frequency operation, with lower resultant system weight and volume. Recently, commercially available SiC power devices have recently entered the market with force, predicted to be worth $2bn by 2024, with rapid growth in this technology is being actively driven by a number of early adopters in the automotive sector, e.g. Tesla. However for high voltage (>1.7 kV) power transmission, bipolar Silicon devices (IGBTs, GTOs) are more efficient - so the technology must presently be chosen relative to application. To remove this restriction, SiC power devices of all types can be additionally bolstered by SuperJunction (SJ) technology, improving the efficiencies of the material and fully ready to challenge Si technology. This proposal intends on developing new 6.5 kV SiC SJ materials and devices technology for the goal of increased power transmission. Current research in SiC SJ devices consists only of a handful of reports on single devices, whilst encouraging, the technology is still in its infancy. The UK has an opportunity to develop the technology from the ground up and become a serious international name. The major challenge being that SiC processing methods fall short of being able to mass-produce the superjunction material, with one method being expensive and complicated, another requiring very tight precision of parameters and the last compromising on current rating.Specifically here we propose to develop Trench Epitaxy (TE), which deposits crystalline materials in very high aspect ratio micro trenches. The deposition method is chemical vapour deposition (CVD), which is accepted as the industry gold standard of fast throughput, high quality materials production and so must be the method of choice when developing this technology. The challenges in developing TE lie in the transport of the gases to the bottom of the trenches to a) etch the material, b) condition it ready for deposition and c) fully refilling the trenches with modified material and d) ensuring the surface is returned to its previous state. The more complex challenges lie in the non-mutually exclusive chemical nature of the work, where a change in one parameter may change many more.Warwick currently houses the only industrial SiC CVD in the UK, has a dedicated SiC device fabrication cleanroom and many analytical tools so is the ideal place for the UK to enter this field with the view to contributing to the technology at the point of entry. The University of Warwick is a key member of EPSRC Centre for Power Electronics and is part of the £17M APC-12 ESCAPE (End-to-end Supply Chain development for Automotive Power Electronics) project which is developing a UK centred SiC production line, led by McLaren, so pathways exist of fully implementing TE SiC SJ technology after development.

2019年，英国32千兆瓦的日均能源需求中有48.5%是无碳能源--由风力发电场、太阳能和核能以及通过海底连接器和生物质能源进口的能源贡献。这一趋势支持了政府在2019年签署的“净零”承诺。然而，仍需要开发重要的技术来实现这一目标。一项关键的此类技术是高压直流(HVDC)网格级输电，它将使“超级电网”成为可能。这是一个跨越国家和国家之间的长距离输电线路网络，以及上述能源生产设施，特别是在偏远地区，如海上风电场。提高每个电网互联的效率和额定功率(以及减少其体积和重量)将意味着更广泛的实施，从而为英国提供更好的能源安全、更低的碳足迹和更好的能源经济。在大多数互连中，50%的体积是电力电子器件，传统上是由硅技术制造的。碳化硅(SIC)与现有的硅技术相比具有明显的优势，如高温和高频工作，所生成的系统重量和体积较小。最近，商业上可用的碳化硅功率器件最近大举进入市场，预计到2024年价值将达到20亿美元，这项技术的快速增长正受到汽车行业一些早期采用者的积极推动，例如特斯拉。然而，对于高压(&GT；1.7千伏)输电，双极型硅器件(IGBT、GTO)效率更高，因此目前必须根据应用情况选择该技术。为了消除这一限制，所有类型的碳化硅功率器件都可以通过超结(SJ)技术得到额外的支持，从而提高材料的效率，并完全准备好挑战硅技术。该方案旨在开发新的6.5kVSiCSJ材料和器件技术，以实现增加功率传输的目标。目前对SIC SJ设备的研究仅包括少数关于单个设备的报告，虽然令人鼓舞，但该技术仍处于初级阶段。英国有机会从头开始发展这项技术，并成为一个严肃的国际品牌。主要的挑战是，碳化硅的加工方法不能大规模生产超结材料，一种方法昂贵而复杂，另一种方法对参数的精度要求非常高，最后一种方法对电流额定值的影响很小。具体地说，我们建议开发沟槽外延(TE)，它在非常大的长宽比微沟槽中沉积晶体材料。沉积方法是化学气相沉积(CVD)，它被公认为快速生产、高质量材料生产的工业黄金标准，因此必须成为开发这项技术时的选择方法。发展TE的挑战在于将气体输送到沟槽底部，以a)蚀刻材料，b)使其准备好沉积，c)用改性材料充分填充沟槽，以及d)确保表面恢复到以前的状态。更复杂的挑战在于这项工作的非互斥化学性质，其中一个参数的变化可能会改变更多。华威目前拥有英国唯一的工业碳化硅CVD，拥有专用的碳化硅器件制造净化室和许多分析工具，因此是英国进入这一领域的理想场所，以期在入口点为技术做出贡献。华威大学是EPSRC电力电子中心的重要成员，也是GB 17M APC-12 EASH(汽车电力电子端到端供应链开发)项目的一部分，该项目正在开发一条以英国为中心的由迈凯轮领导的碳化硅生产线，因此在开发后全面实施TE SJ技术是有路径的。