A method of forming a semiconductor structure can include forming a photolithography mask on a silicon fin having a hard mask layer thereon extending in a first direction. A trench can be formed through the hard mask layer into the silicon fin using the photolithography mask, where the trench extends in a second direction to separate the silicon fin into first and second fin structures extending end-to-end in the first direction. A portion of the trench formed by the hard mask layer can be widened relative to a lower portion of the trench defined by the first and second fin structures.