Carrier Transport in Advanced Silicon Carbide (SiC) Devices

[207093]本研究项目旨在研究先进碳化硅（SiC）器件中的载流子输运。研究重点是先进SiC器件的建模，制造和电气特性，包括n沟道和p沟道mosfet，以及新型表面和埋道DIMOS和IGBT器件，特别强调它们在功率开关应用中的应用。该研究强调了低温制造序列的发展，以减少“阶梯聚束”的有害影响，同时实现植入物种所需的激活。该研究的目标是通过结合低温处理和优化栅极电介质来提高载流子反转和积累层迁移率。该研究的重点是载流子迁移率的物理建模，其中电子在SiC-SiO2界面上以局域状态移动，并在导带中被热激活为扩展状态。热活化、表面粗糙度和点库仑散射的结合都限制了载流子迁移率，从而限制了SiC功率mosfet的特定ON电阻。电子和空穴输运的研究在平面SiC集成电路技术中非常重要，特别是在“智能”电源应用中。该研究采用新颖的测试结构、制造技术和仪器来研究表面和体阱对反转和层中载流子输运的影响，同时有助于SiC器件，特别是功率半导体器件的进步。

0207093WhiteThis research program addresses the study of carrier transport in advanced silicon carbide (SiC) devices. The research focuses on the modeling, fabrication and electrical characterization of advanced SiC devices, including n and p-channel MOSFETs, and novel surface and buried-channel DIMOS and IGBT devices with particular emphasis on their utilization for power switching applications. The research emphasizes the development of a low temperature fabrication sequence to reduce the detrimental effects of 'step bunching', while simultaneously achieving the required activation of the implanted species. A goal of the research is to increase carrier inversion and accumulation-layer mobility through a combination of low temperature processing with an optimized gate dielectric. The research focuses on the physical modeling of carrier mobility where electrons move in localized states at the SiC-SiO2 interface and are thermally activated into extended states in the conduction band. A combination of thermal activation, surface roughness and point Coulomb scattering all play a role in limiting the carrier mobility and hence the specific ON resistance of SiC power MOSFETs. The study of both electron and hole transport is important in planar SiC integrated circuit technology, particularly for 'smart' power applications. The research employs novel test structures, fabrication techniques and instrumentation to study the influence of surface and bulk traps on carrier transport in inversion and layers over an extended temperature range, while contributing to the advancement of SiC devices, particularly power semiconductor devices.