With the rise of gallium nitride (GaN) and the booming market of low and medium power diodes, the excellent properties of GaN materials such as wide band gap and high thermal conductivity are receiving much more attention in manufacturing devices. In this paper, the new devices with micron column schottky contact are shown, and the diameter of each micron column is 5 μm. By varying the spacing of the micron column, an ultra-low R_on,sp of 0.07 mΩ·cm² and a low V_on of 0.45 V for the diode are achieved.The SBD in this work achieves a power device figure-of-merit V_BR²/R_ON of 6.6 GW/cm², which is the highest FOM among the reported data so far. And, these SBDs are reaching the theoretical limit of GaN material.