Method of manufacturing fin field effect transistor

A method of manufacturing a fin field effect transistor, comprising:

• a) providing an SOI substrate comprising a substrate layer (100), a BOX layer (120) and an SOI layer (130);
• b) forming a basic fin structure from the SOI layer;
• c) forming source/drain regions (110) on both sides of the basic fin structure;
• d) forming a fin structure between the source/drain regions (110) from the basic fin structure;
• e) forming a gate stack across the fin structure;
• wherein:
• in the step b), the basic fin structure is covered with a first dielectric layer (150);
• in the step c), the source/drain regions (110) are formed on both sides of the basic fin structure in a length direction, and the source/drain regions are covered with a second dielectric layer (160), wherein a material of the second dielectric layer is different from that of the first dielectric layer;
• in the step d), the source/drain regions (110) on both sides of the basic fin structure in the length direction and the fin structure between the second dielectric layer (160) along the length direction are formed from the basic fin structure;
• and step f) is performed before the step e):
• in the step f), a spacer (210) is formed on sidewalls of the SOI layer (130) exposed and the source/drain regions (110);
• and
• in the step e), a gate dielectric layer (220) covering the fin structure and a gate metal layer (230) covering the gate dielectric layer in a trench are formed.