A method of forming a semiconductor structure comprises providing a semiconductor substrate. A feature is formed over the substrate. The feature is substantially homogeneous in a lateral direction. A first ion implantation process adapted to introduce first dopant ions into at least one portion of the substrate adjacent the feature is performed. The length of the feature in the lateral direction is reduced. After the reduction of the length of the feature, a second ion implantation process adapted to introduce second dopant ions into at least one portion of the substrate adjacent the feature is performed. The feature may be a gate electrode of a field effect transistor to be formed over the semiconductor substrate.