A forming method of a fin type
field effect transistor includes the steps: providing a substrate, wherein a plurality of separate fins are formed on the surface of the substrate, and a grid
electrode structure crossing the fins is formed on the surface of the substrate; forming spacer films on the sidewall of the grid
electrode structure, the top surface of the grid
electrode structure, sidewalls of the fins, top surfaces of the fins and the surface of the substrate; conducting back
etching on the spacer films through an
anisotropic etching process, removing the spacer films on the surface of the substrate, the top surface of the grid electrode structure and the top surfaces of the fins, forming a first spacer on the sidewall of the grid electrode structure, and forming second spacers on the sidewalls of the fins; carrying out
doping processing on the first spacer, and reducing the
etching rate of the
isotropic etching process for the first spacer;
etching and removing the second spacers through an
isotropic etching process, making the sidewalls of the fins exposed, and keeping the first spacer of the sidewall of the grid electrode structure; forming doped regions inside the fins at the two sides of the first spacer; and forming
metal contact
layers on the sidewalls and the top surfaces of the fins. The
contact resistance of a fin type
field effect transistor is reduced, and the response speed of the fin type
field effect transistor is increased.