This study reports a pentacene patterning method that can be combined with conventional lithography to pattern pentacene film. The aluminum nitride (AlN) surface was patterned using a conventional photolithography process and then treated with oxygen (O2) plasma on uncovered AlN to modify surface polarity. Following pentacene deposition, the sample was dipped in water to remove pentacene from the O2 plasma-treated area. The O2 plasma-treated AlN surface was analyzed using X-ray photoelectron spectroscopy (XPS) before pentacene deposition. The polar surface energy changed from 13.2 to 114.4 mJ m2 when the AlN surface was treated with O2 plasma at 100 W for 10 min. The polar surface energy was attributed to the increase of Al-O bonds on the surface based on XPS measurements. The intrusion energy of water was enhanced from 34.5 to 140.4 mJ m2 due to the polar surface energy induced by the O2 plasma treatment. The enhancement of water intrusion energy and the polar surface energy explains the water-removable pentacene patterning mechanism.