Fin cut profile using fin base liner

[0020]Embodiments of the present invention provide semiconductor devices that have superior fin length uniformity. This is accomplished by forming a protective liner at the base of the hardmask fins before cutting the hardmask fins to size. The protective liner enables the use of an etch chemistry that provides a superior hardmask fin profile without risking damage to the underlying semiconductor substrate.

[0021]Referring now to the drawings in which like numerals represent the same or similar elements and initially to FIG. 1, a cross-sectional view of a step in the formation of a set of semiconductor fins having sharp fin profiles is shown. A set of hardmask fins 104 is formed on a semiconductor layer 102. The composition of the hardmask fins 104 is shown herein as being a single layer of dielectric material, such as silicon nitride, but it should be understood that other compositions are contemplated, in particular fins formed from alternating layers of silicon oxide and silicon nitr