The present invention relates generally to semiconductor devices, and particularly to fabricating a shallow trench isolation (STI) region in fin field effect transistors (FinFETs) having a small fin pitch. According to one embodiment, a method of using selective etching techniques to remove a single fin to form a fin trench and to form an isolation trench having a width approximately equal to a width of the single fin below the removed fin is disclosed. The fin trench and the isolation trench may be filled with isolation material to form an isolation region.