Method for fabricating asymmetrical three dimensional device

A method of forming an asymmetrical three dimensional semiconductor device, comprising:

• providing a fin structure extending perpendicularly from a substrate plane and having a fin axis, the fin axis lying parallel to the substrate plane, and parallel to a direction of current flow through a channel region, wherein a portion of the fin structure is covered by a gate structure defining the channel region, wherein the fin structure comprises a top surface that is covered by the gate structure, and wherein the fin structure comprises a first end surface not covered by the gate structure and second end surface not covered by the gate structure;
• and
• directing ions in a fin treatment to the fin structure, wherein the fin treatment comprises a first treatment of the first end surface and a second treatment of the second end surface different from the first treatment, wherein the top surface does not extend beyond the gate structure in a direction parallel to the fin axis during the fin treatment, and wherein the top surface extends from the first end surface to the second end surface during the fin treatment.