Method of forming a silicon-carbide device with a shielded gate

Disclosed is a method of forming a silicon-carbide device with a shielded gate. The silicon-carbide semiconductor substrate has a plurality of first doped regions being laterally spaced apart from one another and beneath a main surface, and a second doped region extending from the main surface to a third doped region that is above the first doped regions is formed. Fourth doped regions extending from the main surface to the first doped regions are formed. A gate trench having a bottom that is arranged over a portion of one of the first doped regions is formed. A high-temperature step is applied to the substrate so as to realign silicon-carbide atoms along sidewalls of the trench and form rounded corners in the gate trench. A surface layer that forms along the sidewalls of the gate trench during the high-temperature step from the substrate is removed. 本公开涉及形成具有屏蔽栅极的碳化硅器件的方法，其中，提供了一种碳化硅半导体衬底，其具有彼此横向间隔开并且在主表面之下的多个第一掺杂区域，以及形成从主表面延伸到在第一掺杂区域之上的第三掺杂区域的第二掺杂区域。形成从主表面延伸到第一掺杂区域的第四掺杂区域。形成具有布置在第一掺杂区域中的一个区域的一部分之上的底部的栅极沟槽。对