Field effect transistor and manufacturing method thereof

A manufacturing method of a field effect transistor, comprising:

• providing a substrate;
• forming a fin bump on the substrate;
• forming an insulating layer on the substrate, the insulating layer being located at two sides of the fin bump;
• disposing a charge trapping material on the fin bump and the substrate;
• etching part of the charge trapping material covering the fin bump to expose part of the fin bump;
• forming a gate structure covering the fin bump and the charge trapping material;
• and
• etching the charge trapping material by using the gate structure as a mask to form a charge trapping structure, wherein the charge trapping structure is disposed on the insulating layer and located at least one side of the fin bump, a cross-section of the charge trapping structure is L-shaped, the charge trapping structure covers part of the lateral wall of the fin bump, a top of the charge trapping structure is lower than a top of the fin bump and higher than a bottom of the fin bump, and none of the charge trapping structure is on the top of the fin bump.