Method for preparing metal pattern for fin field effect transistor

The invention provides a method for preparing a metal pattern for a fin field effect transistor. The method comprises steps of: providing a target pattern layout of a metal layer pattern, inverting and then splitting a target pattern in the target pattern layout into a line layer pattern layout and a line end cutting layer pattern layout; providing a substrate layer having a fin layer and a gate layer; depositing a dielectric layer and a first hard mask layer on the substrate; etching a line layer pattern in the first hard mask layer by using the line layer pattern layout and a lithography and etching process; cutting the line end of a corresponding line layer pattern in the first hard mask layer by using the line end cutting layer pattern layout and the lithography and etching process; depositing a second hard mask layer on the line layer pattern and the exposed dielectric layer; removing the line layer pattern of the first hard mask layer and retaining the second hard mask layer; etching the dielectric layer by using the second hard mask layer as a mask, and forming a trench pattern in the dielectric layer; filling the trench pattern with metal and planarizing the metal surface to form the metal pattern.