FIN-SHAPED STRUCTURE FORMING PROCESS

A fin-shaped structure forming process includes the following step. A first mandrel and a second mandrel are formed on a substrate. A first spacer material is formed to entirely cover the first mandrel, the second mandrel and the substrate. The exposed first spacer material is etched to form a first spacer on the substrate beside the first mandrel. A second spacer material is formed to entirely cover the first mandrel, the second mandrel and the substrate. The second spacer material and the first spacer material are etched to form a second spacer on the substrate beside the second mandrel and a third spacer including the first spacer on the substrate beside the first mandrel. The layout of the second spacer and the third spacer is transferred to the substrate, so a second fin-shaped structure and a first fin-shaped structure having different widths are formed respectively.