Semiconductor element and manufacturing method thereof

The invention discloses a semiconductor element and a manufacturing method thereof, and the method for manufacturing the semiconductor element mainly comprises the steps: providing a substrate which comprises a high-voltage region and a low-voltage region, and forming a plurality of first fin-shaped structures in the high-voltage region; an oxidation process is then performed to form a gate oxide layer on the first fin-shaped structures and contacting the first fin-shaped structures. In the embodiment, the bottom surface of the gate oxide layer comprises a plurality of first bumps arranged on the first fin-shaped structures, and the top surface of the gate oxide layer comprises a plurality of second bumps. 本发明公开一种半导体元件及其制作方法，其中该制作半导体元件的方法主要先提供一基底包含一高压区以及一低压区，形成多个第一鳍状结构于该高压区，再进行一氧化制作工艺以形成一栅极氧化层于该等第一鳍状结构上并接触该等第一鳍状结构。在本实施例中，栅极氧化层底表面包含多个第一突块设于该等第一鳍状结构上而栅极氧化层顶表面则包含多个第二突块。