US Patent 11664454 Method for forming semiconductor device structure

A method for forming a semiconductor device structure is provided. The method includes forming a semiconductor fin structure over a substrate, forming a dielectric fin structure laterally spaced apart from the semiconductor fin structure, forming a source/drain spacer between the semiconductor fin structure and the dielectric fin structure, etching an upper portion of the semiconductor fin structure to expose a lower portion of the semiconductor fin structure, and forming a source/drain feature over the lower portion of the semiconductor fin structure. The source/drain spacer is interposed between the source/drain feature and the dielectric fin structure.