Semiconductor element and manufacturing method thereof

A semiconductor device includes a substrate, an active region on the substrate, a recessed region in the active region, a gate dielectric layer on the recessed region, and a gate dielectric layer on the gate dielectric layer. Wherein an edge portion of the gate dielectric layer has a rounded profile, a gate structure on the gate dielectric layer, and a source/drain region in the active region on one side of the gate structure and in direct contact with the edge portion of the gate dielectric layer. 本发明公开一种半导体元件及其制作方法，其中该半导体元件包括一基底，一主动区位于该基底上、一凹陷区域位于该主动区中、一栅极介电层位于该凹陷区域上，其中该栅极介电层的一边缘部分具有一圆化轮廓、一栅极结构位于该栅极介电层上，以及一源/漏区位于该栅极结构一侧的该主动区中，并且与该栅极介电层的该边缘部分直接接触。