Product comprised of FinFET devices with single diffusion break isolation structures, and methods of making such a product

A method, comprising:

• forming a plurality of trenches in a semiconductor substrate to thereby define first, second and third fins in said substrate that are positioned side-by-side, wherein said second fin is positioned between said first and third fins;
• forming a layer of insulating material in said plurality of trenches;
• performing at least a recess etching process on said layer of insulating material such that it has a recessed upper surface that exposes a desired height of said first, second and third fins;
• after performing said recess etching process, performing a conformal deposition process to form a conformal etch mask material layer on said first, second and third fins and on said recessed upper surface of said recessed layer of insulating material;
• forming a patterned photoresist etch mask above said conformal etch mask material layer;
• performing an etching process through said patterned photoresist etch mask so as to pattern said conformal etch mask material layer and thereby define a patterned conformal etch mask layer that covers said first and second fins and exposes a portion of the axial length of said second fin;
• removing said patterned photoresist etch mask;
• with said patterned conformal etch mask layer in position, performing an etching process to remove at least some of said exposed portion of said second fin so as to thereby define a cavity in said recessed layer of insulating material;
• forming an SDB isolation structure in said cavity, wherein said SDB isolation structure has an upper surface that is positioned at a level that is above a level of said recessed upper surface of said recessed layer of insulating material;
• removing said patterned conformal etch mask layer;
• and
• forming a gate structure for a transistor above said SDB isolation structure.