US Patent 10971405 Semiconductor devices and fabrication methods thereof

A method for fabricating a semiconductor device includes providing a base substrate, including a first region and a second region. The first region is located on each side of the second region, and a plurality of fin structures is formed in the first region and the second region. The method includes forming a first doped region and a second doped region in the first region and the second region, respectively in the plurality of fin structures. The concentration of doping ions in the first doped region is lower than that in the second doped region, and the doping ions in the first doped region and the second doped region are the same doping type. After forming the first doped region and the second doped region, the method includes forming a plurality of gate structures on the first doped region and the second doped region across the plurality of fin structures.