| 초록 |
There is an enormous widespread interest in nanomaterials and their size-dependent properties. Several methods have been established for the nanopattern, especially different kind of lithography techniques. Photolithography is most commonly used for patterning, but not useful for nanopattern. Nano imprint lithography is another one for nanopatterning. But this technique requires expensive equipment. Nanosphere lithography (NSL) is an inexpensive, simple, high throughput nanofabrication process. It makes use of placing nanospheres in a tightly packed pattern on a substrate in order to create a mask for pattern transfer, and the nanopattern is achieved after deposition of thin film and removal of nanosphere. The space between the orderly packed polystylene spheres was controlled by the O2 plasma ashing. Nitride based light emitting diodes (LED) are applied in different places like, liquid crystal display and traffic signal. Its characteristics can be enhanced by making nanopattern on the upper surface of GaN based LED. In this work, we have fabricated the nanopattern on the top surface of GaN based LED by NSL technique and Reactive Ion Etching. The characteristics of nanopattern depended on the size of the spheres and also the space between the two spheres. The photoluminescence intensity was increased with the increase of size, as well as increase of the space between two spheres. Current-voltage characteristic was also improved by making the different size patterning using nanosphere lithography.
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