Development of Silicon Carbide devices for next generation surge protection circuitry and power electronics

该项目主要围绕新型半导体器件的设计、制造和建模，范围可以进一步扩大；因为有兴趣最终使全SiC集成电路提供革命性的好处，如在极端温度和环境下的操作。就项目目标而言，研究工程师将：-开发用于TBU的新型宽带隙碳化硅器件。-创建能够扩展到工业制造的设备。直接与Bourns公司的研发工程师合作，优化JFET器件，并在商业制造环境中获得宝贵的经验。- SiC集成电路；通过CISM潜在地开发利基SiC半导体工艺技术，以提高控制器芯片本身的性能。-研究其他有前途的宽禁带材料，如氮化镓mosfet和氧化镓FET器件，以进一步降低成本。burns, Inc.是一家在功率半导体器件和电力电子领域拥有强大研发记录的全球性公司。七十多年来，Bourns一直是可靠的高品质电子元件和解决方案的全球领先供应商，这些元件和解决方案已被设计成几乎所有类型的电子系统，包括汽车，电信，计算机和工业应用。伯恩斯的英国贝德福德分公司作为电路保护半导体的领先制造商享有盛誉。他们将很快推出新的功率半导体器件系列，这是在英国制造的第一代650V igbt。这些设备非常适合电动汽车，战略性地使伯恩斯成为这个快速扩张市场的未来供应商。由于碳化硅具有优越的物理性能，市场对高效节能电子产品的需求已经转向了作为半导体材料的碳化硅，以配合低碳技术。这一趋势在未来只会加速。伯恩斯正在积极开展这一领域的研究，并将寻求利用这种材料来补充和扩大其产品组合。在电动汽车市场的推动下，SiC功率器件市场将呈指数级增长。鉴于英国政府宣布到2035年禁止所有柴油、汽油甚至混合动力汽车，这个项目的及时性再好不过了（见https://www.bbc.co.uk/news/science-environment-51366123）。此外，还有一个更广泛的、到2050年实现净零碳排放的目标。混合动力(HEV) /纯电动汽车（BEV）动力系统的趋势是利用高电池容量系统，将直流电压提高到600V以上。这里的目的是减少目前阻碍电动汽车性能的苛刻的布线要求。超过600V，唯一可行的功率半导体器件选项，可以达到所需的效率水平是SiC。功率mosfet将在主逆变器动力系统中使用，如果需要，包括直流升压变换器级。此外，到2023年，这些高压电动汽车的销量将达到1800万辆，占全球汽车总销量的16.2%。电气化的范围越来越广，对电涌保护技术的需求也越来越大。JFET技术今天建立在碳化硅上。栅极氧化物的缺乏使其成为制造可靠开关器件的理想方法。虽然jfet在商业上可用，但它们并没有像TBU那样针对电流限制应用进行优化。控制JFET器件的阈值电压和导通电阻是在无浪涌运行时保持低损耗以及在浪涌出现时有效关断的敏捷控制的关键。

This project is focussed around novel semiconductor device design, fabrication and modelling and the scope can be expanded further; as there is interest in eventually making full SiC Integrated Circuits to provide revolutionary benefits such as operation at extremes of temperature and environment. In terms of project aims, the Research Engineer will:- Develop novel wide bandgap silicon carbide devices for application with the TBU.- Create devices capable of being scaled up to industrial manufacturing. Working directly with R&D engineers at Bourns, Inc. to optimise the JFET device and gain valuable experience in a commercial fabrication environment.- SiC ICs; potentially develop niche SiC semiconductor process technology through CISM to improve the performance of the controller chip itself.- Investigate other promising wide bandgap materials such as Gallium Nitride MOSFETs and even Gallium Oxide FET devices to further lower cost.BackgroundBourns, Inc., is a global company with a strong Research and Development record in Power semiconductor devices and power electronics. For over seventy years, Bourns has been a leading global supplier of reliable high-quality electronic components and solutions, which have been designed into virtually every type of electronic system including automotive, telecommunications, computers and industrial applications. The Bedford, UK branch of Bourns has an established reputation as a leading manufacturer of circuit protection semiconductors. They will soon be launching a new line of power semiconductor devices, a first generation of 650V IGBTs manufactured in the UK. These devices are ideally suited for electric vehicles, strategically placing Bourns as a future supplier in this rapidly expanding market. The demand for high efficiency energy saving electronics to compliment low carbon technologies has already seen a market shift to silicon carbide as a semiconductor material, owing to its superior physical properties. A trend that is only going to accelerate in the future. Bourns is actively performing research in this area and will look to harness this material to compliment and expand its product portfolio.The market for SiC power devices is set to grow exponentially - driven by the electric vehicles market. The timeliness of this project could not be any better given the UK government's announcement to ban all diesel, petrol and even hybrid vehicles by 2035 (see https://www.bbc.co.uk/news/science-environment-51366123). This is compounded by an additional wider, net zero carbon emissions target, by 2050. The trend in terms of hybrid (HEV) / battery electric vehicle (BEV) powertrains is to push the DC voltage to beyond 600V, utilising high battery capacity systems. The purpose here is to reduce the demanding cabling requirements currently hampering electric vehicle performance. Beyond 600V, the only viable power semiconductor device option that can achieve the required efficiency levels is SiC. Power MOSFETs will be used within the main inverter powertrain, including a DC boost converter stage if required. Moreover, these higher voltage electric vehicle sales are set to reach 18 million by 2023, representing 16.2% of total global vehicle sales. The wider electrification becomes the more need for surge protection technologies. JFET technology is today established in silicon carbide. The lack of a gate oxide makes it a desirable method to manufacture reliable switching devices. Although JFETs are commercially available they are not optimised for current limiting applications as utilised by the TBU. Control of threshold voltage and on-resistance of JFET devices is key to maintain low-loss in non-surge operation as well as agile control, turning off effectively when a surge appears.