Fabrication of a pair of vertical fin field effect transistors having a merged top source/drain

A method of fabricating two vertical fin field effect transistors electrically coupled through a merged top source/drain, comprising:

• forming a source/drain layer on a substrate;
• forming at least four vertical fins on the source/drain layer;
• forming an isolation region trench between the two protective spacers;
• forming a dummy layer in the isolation region trench;
• forming a trench fill layer in the isolation region trench to form an isolation region through the source/drain layer to separate the source/drain layer into a first bottom source/drain and a second bottom source/drain, wherein at least two of the least four vertical fins are on the first bottom source/drain, and at least two of the least four vertical fins are on the second bottom source/drain.

A method of forming an adjoined pair of vertical fin devices, comprising:

• forming a first bottom source/drain and a second bottom source/drain on a substrate, wherein the first bottom source/drain is separated from the second bottom source/drain by a shallow trench isolation region in the substrate;
• forming at least four vertical fins, wherein at least two of the at least four vertical fins are on the first bottom source/drain and at least two of the at least four vertical fins are on the second bottom source/drain;
• forming a first gate structure on the at least two vertical fins on the first bottom source/drain;
• forming a second gate structure on the at least two vertical fins on the second bottom source/drain;
• forming a top source/drain on at least one of the at least two vertical fins on the first bottom source/drain;
• and
• forming a top source/drain on at least one of the at least two vertical fins on the second bottom source/drain, wherein the top source/drain on at least one of the at least two vertical fins on the first bottom source/drain and the top source/drain on at least one of the at least two vertical fins on the second bottom source/drain coalesce into a merged source/drain on one vertical fin on the first bottom source/drain and one adjacent vertical fin on the second bottom source/drain that bridges the shallow trench isolation region to electrically couple the adjacent vertical fins.