Surface property study of different patterning sapphire structures by ICP-RIE

In this paper, we demonstrate and compare the formation of ordered etching masks for submicron patterned sapphire through use of the nanosphere lithography and nanoimprint lithography methods. Both NSL and NIL were applied to produce the submicron honeycomb network and cone protrusion array structure on the sapphire surface as etching masks. The sequent ICP-RIE technique was applied to further etch the sapphire under the mask. Two types of submicron pattern were obtained on the substrate surface after the etching processes were completed. One type of substrate was the submicron hole array structure and another type was the cone array structure. The working pressure had a considerable effect on the shape geometry and etching rate. The contact angles of the untreated substrate and two differing patterned sapphire substrates were measured and compared. From the contact angle measurement results, we concluded that the protruded contact area dominated the hydrophobic or hydrophilic property.