Semiconductor device

A semiconductor device is provided. In one embodiment, a method is disclosed. In one embodiment, a semiconductor device includes a first nanostructure directly over a first portion of a substrate and a second nanostructure directly over a second portion of the substrate, an n-type source/drain feature coupled to the first nanostructure and a p-type source/drain feature coupled to the second nanostructure, and an isolation structure disposed between the first portion of the substrate and the second portion of the substrate. The isolation structure includes a first smile region directly contacting the first portion of the substrate and having a first height. The isolation structure also includes a second smile region directly contacting the second portion of the substrate and having a second height, the first height being greater than the second height. 提供半导体装置。在一实施例中，半导体装置包含在基底的第一部分正上方的第一纳米结构和在基底的第二部分正上方的第二纳米结构、耦合至第一纳米结构的n型源极/漏极部件和耦合至第二纳米结构的p型源极/漏极部件、以及设置在基底的第一部分和基底的第二部分之间的隔离结构。隔离结构包含直接接触基底的第一部分并具有第一高度的第一微笑区。隔