| 학회 | 한국재료학회 |
| 학술대회 | 2008년 가을 (11/07 ~ 11/07, 차세대융합기술연구원) |
| 권호 | 14권 2호 |
| 발표분야 | 반도체재료 |
| 제목 | Full wafer scale imprinting process for the fabrication of two-dimensional photonic crystals on GaN-based light-emitting diodes |
| 초록 | Conventional GaN-based LEDs have been suffered by low photon extraction efficiency due to total internal reflection, caused by large difference in refractive index between GaN-based materials (nGaN ≈ 2.5) and air (nair = 1). To solve this problem, two-dimensional (2-D) photonic crystal patterns have been extensively studied in many research groups. However, it is very difficult to commercialize the photonic crystal patterned LED due to high cost patterning technique such as photolithography and e-beam lithography. In this work, 2-D photonic crystal patterns were formed on p-GaN top cladding layer of InGaN-based LED wafer by UV nanoimprint lithography. Whole surface of 2 inch diameter wafer was patterned by single nanoimprint process. To compensate poor flatness of the LED substrate, flexible transparent polymer mold, which was replicated from Si master mold by imprinting and embossing processes, was used for UV imprinting process. By UV imprinting process at condition of 30 atm and 10 min of UV exposure time, patterns of the polymer mold were uniformly transferred on the p-GaN layer of the LED wafer with 2 inch full area. And the p-GaN layer, masked by imprinted pattern, was etched by SiCl4/Ar plasma. As a result, photonic crystal patterns with various sized hole array were successfully fabricated in the p-GaN top cladding layer with 2 inch full area of LED substrate. |
| 저자 | 변경재, 홍은주, 이 헌 |
| 소속 | 고려대 신소재공학과 |
| 키워드 | light-emitting diodes; photonic crystal; nanoimprint; polymer mold |
