抑制4H-SiC功率器件双极型退化的复合提高层设计

Design a Recombination-enhancing Layer for Preventing 4H-SiC Power Device Bipolar Degradation

"双极型退化"是目前影响4H-碳化硅(SiC)双极型器件稳定工作的重要问题。针对此现象,以万伏级的超高压PiN二极管为例,详细介绍在衬底与外延层之间如何设计合适的"复合提高层"以抑制双极型退化。研究了器件工作电流密度和"复合提高层"少子寿命对设计"复合提高层"的影响。结果表明,在一定的工作电流密度下,"复合提高层"少子寿命越短,所需"复合提高层"厚度越薄。

"Bipolar degradation"is an important problem affecting the stability of 4 H-silicon carbide(SiC)bipolar devices.A 10 kV ultra-high voltage PiN diode is taken as an example,and how to design an appropriate"recombinationenhancing layer"between a substrate and an epitaxial layer to prevent"bipolar degradation"is introducd in detail.The effects of current injection density and minority carrier lifetime of the designed layer on the designed"recombination-enhancing layer"are separately studied.The results show that under a certain working current density,the shorter the minority carrier lifetime of the"recombination-enhancing layer",the thinner the designed layer thickness is required.