Semiconductor device and manufacturing method thereof

The invention discloses a semiconductor device and a manufacturing method thereof. The semiconductor device comprises a semiconductor substrate, a recess, a first gate oxide layer and a gate structure. The semiconductor substrate includes a first region and a second region adjacent to the first region. The recess is disposed in the first region of the semiconductor substrate, and an edge of the recess is located at a junction between the first region and the second region. The first gate oxide layer is at least partially disposed in the recess. The first gate oxide layer includes a protrusion disposed adjacent to the edge of the recess, and the height of the protrusion is smaller than the depth of the recess. The gate structure is disposed on the first region and the second region of the semiconductor substrate, and the gate structure overlaps the bump of the first gate oxide layer in a vertical direction. 本发明公开一种半导体装置以及其制作方法，其中该半导体装置包括半导体基底、凹陷、第一栅极氧化物层以及栅极结构。半导体基底第一区以及与第一区相邻的第二区。凹陷设置于半导体基底的第一区中，且凹陷的一边缘位于第一区与