1. A method of fabricating a pore, comprising: providing a layer of a first material; forming a layer of a second material on said layer of said first material; forming a layer of a third material on said second material; forming a sidewall surface in said layer of said third material; forming a layer of a forth material on said layer of said third material; removing a portion of said layer of said forth material; and removing a portion of said layer of said second material to define said pore in said layer of said second material.