Development of silicon carbide plasma etch processes for next generation power electronics

开发下一代电力电子产品的碳化硅等离子体蚀刻工艺

• 批准号: 2441670
• 金额: --
• 依托单位: Swansea University
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2441670
• 关键词: Development; silicon; carbide; plasma; etch

The Research Engineer will develop new processes for plasma etching of Silicon Carbide (SiC) and develop new applications in Power Electronic based on SiC devices.The market for SiC power devices is set to grow exponentially - driven by the electric vehicles market. 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. 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. When one considers that this represents 16.2% of total global vehicle sales, the market relevance becomes obviously apparent.The Research Engineer will develop process technology for SiC devices, plasma dicing and new mask coatings. Robust coatings are required for etch-mask materials to pattern and etch trench structures in SiC wafers. These material coatings could be polymers, dielectrics or metals. These coatings will be deposited using SPTS tools for testing. Mask coating development will include conformal dielectric (SPTS MVD system). These coatings will also be trialled for contact pad and gate structures. Further processes will be developed to fabricate metal-oxide-semiconductor field-effect transistors (MOSFETs) in SiC. Novel SiC trench MOSFET designs will be investigated. SiC trench MOSFETs are seen as the future of SiC power devices, with the reduced device pitch enabling a greater number of devices per unit area and thus, enabling lower cost. The challenge is to minimise sidewall microtrenching and striation through efficient mask coatings and process control.These SiC Power devices will be tested for high voltage applications such as high-efficiency inverters in DC/AC converters for solar/wind power supplies and electric/hybrid vehicles power conversion.The Research Engineer will work with the APS SPTS Technologies dielectric etch tool to develop plasma etch recipes to produce vertical side walls. Etch processes will also be investigated further to develop a deep etch process for SiC plasma dicing. Plasma dicing is a signature process for SPTS's silicon etch tools, but dicing technology has not been fully developed for SiC. The future of power electronic devices will require SiC plasma dicing processes to decrease die size and increase fabrication flexibility.The challenges for this project will be the development of the masking material, which needs to maintain high resolution features and survive the intense plasma etch process. Additionally, developing a high power etch process that can etch through SiC at high rates (1 micrometre /minute) whilst maintaining vertical (and smooth trench walls). This will be important for both the development of power devices and the plasma dicing process.The outcomes of the proposed research are multiple and include (i) creating new masking materials for high power vacuum etch tools, (ii) developing new plasma processes for deep SiC etching for both trench and plasma dicing application (iii) characterising new power electronic devices for high voltage applications based on SiC materials.

研究工程师将开发新的流程，用于基于SIC设备的电力电子中的硅碳化物（SIC）并开发新的应用程序。SICPower Devices的市场将呈指数增长 - 由电动汽车市场驱动。混合动力（HEV） /电池电动汽车（BEV）动力总成的趋势是使用高电池容量系统将直流电压推向600V以上。这里的目的是减少目前妨碍电动汽车性能的苛刻电缆要求。超过600V，可以达到所需效率水平的唯一可行的功率半导体设备选项是SIC。 SIC功率MOSFET将在主逆变器动力总成中使用，包括DC增压转换器阶段（如果需要）。此外，到2023年，这些较高的电压电动汽车销售额将达到1800万。当人们认为这占全球汽车总销售额的16.2％时，市场相关性显然显而易见。研究工程师将为SIC设备，等离子体涂抹和新面具涂料开发流程技术。蚀刻涂层材料需要强大的涂层才能在SIC晶圆中进行图案和蚀刻沟结结构。这些材料涂料可能是聚合物，介电或金属。这些涂料将使用SPTS工具进行测试。掩模涂料开发将包括共形介电（SPTS MVD系统）。这些涂层也将进行接触垫和栅极结构的试验。将开发进一步的过程，以制造SIC中的金属氧化物 - 氧化型晶体效应晶体管（MOSFET）。新型的SIC沟渠MOSFET设计将进行研究。 SIC沟渠MOSFET被视为SIC电源设备的未来，降低的设备俯仰可以使每个单位区域的设备数量更多，从而实现了较低的成本。挑战是通过有效的面膜涂层和过程控制来最大程度地减少侧壁微型修理和纹理。这些SIC电源设备将在DC/AC转换器中的高压逆变器等高压逆变器进行测试垂直侧壁。还将进一步研究蚀刻过程，以开发用于SIC血浆dicing的深蚀刻过程。等离子体切割是SPTS硅蚀刻工具的签名过程，但是DICING技术尚未完全开发用于SIC。电力电子设备的未来将需要SIC等离子体划分工艺以降低模具大小并增加制造灵活性。该项目的挑战将是掩盖材料的开发，掩盖材料需要保持高分辨率特征并在强烈的血浆蚀刻过程中生存。此外，开发高功率蚀刻过程，该过程可以以高速（1微米 /分钟）的速度蚀刻SIC，同时保持垂直（和光滑的沟槽壁）。 This will be important for both the development of power devices and the plasma dicing process.The outcomes of the proposed research are multiple and include (i) creating new masking materials for high power vacuum etch tools, (ii) developing new plasma processes for deep SiC etching for both trench and plasma dicing application (iii) characterising new power electronic devices for high voltage applications based on SiC materials.