Patent ID: 8314400

Claim:
A method, comprising: forming a 3-dimentional (3-D) structure comprising a first layer and an array of pillars with cavity regions between said pillars, wherein each pillar of said pillars comprises a first end and a second end, wherein said first end is in contact with said first layer, wherein said first layer comprises only one of n material or p material, wherein each said pillar comprises an intrinsic material; forming a segment on said second end of each said pillar, wherein said segment comprises said p material if said first layer comprises said n material and wherein said segment comprises said n material if said first layer comprises said p material; filling said cavity regions with a fill material, wherein said fill material covers each said segment; removing a first portion of said fill material to produce an exposed portion of said segment; simultaneously depositing an electrode onto said fill material and each said exposed segment, thereby forming a conductive layer that provides a common contact to each said exposed segment; and depositing a second electrode on said first layer.