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

该项目专注于新型半导体器件的设计、制造和建模，范围可以进一步扩大；因为人们有兴趣最终制造全碳化硅集成电路，以提供革命性的好处，如在极端温度和环境下运行。在项目目标方面，研究工程师将：-开发用于TBU的新型宽带隙碳化硅器件。-创造能够扩大到工业制造的器件。与Bourns公司的研发工程师直接合作，优化JFET器件，并在商业制造环境中获得宝贵的经验。-SIC IC；有可能通过CISM开发小众的SIC半导体处理技术，以提高控制器芯片本身的性能。-研究其他有前景的宽带隙材料，如氮化镓MOSFET，甚至是氧化镓FET器件，以进一步降低成本。背景Bourns，Inc.是一家全球性公司，在电力半导体设备和电力电子方面拥有强大的研发记录。70多年来，伯恩斯一直是可靠的高质量电子元器件和解决方案的全球领先供应商，这些元器件和解决方案已被设计用于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。伯恩斯英国贝德福德分公司作为电路保护半导体的领先制造商而享有盛誉。他们很快将推出新的电力半导体器件系列，即英国制造的第一代650V IGBT。这些设备非常适合电动汽车，从战略上使伯恩斯成为这个快速扩张的市场的未来供应商。由于碳化硅具有优越的物理性能，对高效节能电子产品的需求与低碳技术相辅相成，市场已经转向碳化硅作为半导体材料。这一趋势在未来只会加速。伯恩斯正在这一领域积极开展研究，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，碳化硅功率器件的市场将呈指数级增长。考虑到英国政府宣布到2035年禁止所有柴油、汽油甚至混合动力汽车(见https://www.bbc.co.uk/news/science-environment-51366123).)，这个项目的及时性再好不过了到2050年，还有一个更广泛的净零碳排放目标，使这一目标更加复杂。混合动力汽车(HEV)/电池电动汽车(BeV)动力总成的趋势是利用高电池容量系统将直流电压推至600V以上。这里的目的是降低目前阻碍电动汽车性能的苛刻布线要求。在600V以上，能够达到所需能效水平的唯一可行的功率半导体器件选项是SIC。功率MOSFET将在主逆变器动力系统中使用，如果需要，包括DC Boost转换器级。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%。电气化程度越高，对浪涌保护技术的需求就越大。JFET技术今天建立在碳化硅中。栅氧化层的缺乏使其成为制造可靠开关器件的理想方法。尽管JFET是商业上可用的，但它们并没有针对TBU使用的限流应用进行优化。JFET器件的阈值电压和导通电阻的控制是在无浪涌工作时保持低损耗以及灵活控制的关键，当出现浪涌时有效地关断。

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.