Fabrication method for semiconductor device with three or four-terminal-FinFET

A method for forming a semiconductor device, comprising:

• providing a semiconductor substrate including a silicon-on-insulator (SOI) substrate including a top silicon layer;
• forming a first fin and a second fin on the semiconductor substrate by:
• dividing the top silicon layer into a first top silicon layer for forming the first fin and a second top silicon layer for forming the second fin, according to a pre-defined position for forming each of the first fin and the second fin,
• removing a height portion of the second top silicon layer to provide a remaining second top silicon layer;
• and
• patterning the first top silicon layer and the remaining second top silicon layer to form the first fin and the second fin, wherein the first fin has a top surface higher than the second fin from the semiconductor substrate;
• forming a first gate dielectric layer across the first fin, a first gate on the first gate dielectric layer, a second gate dielectric layer across the second fin, and a second gate on the second gate dielectric layer;
• forming an interlayer dielectric layer to cover the first gate, the second gate, and the semiconductor substrate;
• and
• removing a first portion of the interlayer dielectric layer, a portion of the first gate, and a portion of the first gate dielectric layer, over the top surface of the first fin, and a second portion of the interlayer dielectric layer over the second fin to expose the second gate over the second fin, wherein the second gate remains intact while removing, according to a height difference between the first fin and the second fin.