US Patent 9590074 Method to prevent lateral epitaxial growth in semiconductor devices

The method for preventing epitaxial growth in a semiconductor device begins with patterning a photoresist layer over a semiconductor structure having a set of fin ends on a set of fins of a FinFET structure. The set of fins are isolated from one another by a first dielectric material. The photoresist is patterned over the set of fin ends so that it differs from the photoresist pattern over other areas of the FinFET structure. A set of dielectric blocks is formed on the set of fin ends using the photoresist pattern. The set of dielectric blocks prevents epitaxial growth at the set of fin ends in a subsequent epitaxial growth step. In another aspect of the invention, a semiconductor device includes a set of fin structures having a set of fin ends at a respective vertical surface of a fin structure and is separated by a set of trenches from other fin structures. Each of the fin structures has a top surface which is higher than a top surface of a dielectric material in the set of trenches. A set of dielectric blocks is disposed at the set of fin ends, the dielectric blocks having a top surface level with or above the top surfaces of the fin structures which inhibit excessive epitaxial growth at the fin ends.