Manufacturing method for finfet device

Abstract

The invention discloses a manufacturing method for FinFET device, comprises following steps: S01: providing an SOI substrate; S02: covering a middle part of the top silicon layer by using a barrier layer, and performing a silicon ion implantation on the top silicon layer, so that the buried insulator layer under the top silicon layer not covered by the barrier layer is converted into silicon-rich silicon dioxide, wherein in the top silicon layer, the part not covered by the barrier layer is called an implanted region, and the part covered by the barrier layer is called a non-implanted region; S03: removing the barrier layer, define a fin structure in the top silicon layer, the fin structure includes a channel and a source and drain, the source and drain are located on opposite sides of the channel; and the channel in the fin structure is located in the non-implanted region of the top silicon layer, the source and drain are located in the implanted region of the top silicon layer; removing the top silicon layer outside the fin structure; S04: removing the buried insulator layer under the channel in the fin structure to form a suspended channel; S05: forming a completely surrounded dielectric film and a gate in sequence around the suspended channel; S06: forming spacers and a source-drain doping in the structure.