| 학회 | 한국재료학회 |
| 학술대회 | 2014년 가을 (11/27 ~ 11/28, 대전컨벤션센터) |
| 권호 | 20권 2호 |
| 발표분야 | A. 전자/반도체 재료(Electronic and Semiconductor Materials) |
| 제목 | The effects of III-V flux to the growth of non-polar epitaxial AlN films grown by plasma-assisted molecular beam epitaxy |
| 초록 | Due to its very large band gap (＞6eV), high thermal conductivity and stability, aluminum nitride (AlN) is considered as a promising materials for photoelectric devices working in ultra-short wavelength regimes. However, the polar (0001) AlN films are often grown on c-plane (0001) sapphire for commercial purpose exhibit a large internal electric field is induced along [0001] direction. This built-in electric field reduces overlapping of electron and hole wave functions so degrades the performances of photoelectric devices. Furthermore, due to the strong polarization, the AlN LED structure shows much less emission along the conventional polar direction than along nonpolar direction. Non polar films such as m-plane (101 ̅0) and a-plane (112 ̅0) of AlN are believed as a good way to overcome these immanent properties of conventional polar c-plane AlN. However, there are still so few studies about the growth of non-polar AlN film. This study reports effects of III-V flux to the growth of nonpolar AlN films on r-plane sapphire substrate by plasma-assisted molecular beam epitaxy (PAMBE). The growths of main AlN films were taken at 860 °C with the III and V sources from Al effusion cell and nitrogen plasma cell. The effects of III-V source flux ratio on the films were characterized by reflection high energy diffraction (RHEED), atomic force microscopy (AFM) and high-resolution x-ray diffraction rocking curves (XRCs). RHEED in-situ observation showed that in these AlN films grown with low III-V source flux condition, extra crystal-orientations can so appeared beside the principle a-orientation. The higher III-V ratio growth conditions prefer pure a-orientation AlN film with better crystallinity and smoother surface. |
| 저자 | Duc Duy Le1, Soon-Ku Hong2, Dong-Yeob Kim1 |
| 소속 | 1Department of Advanced Materials Engineering, 2Chungnam National Univ. |
| 키워드 | aluminum nitride; epitaxial film; r-plane sapphire; PAMBE; III-Nitrides. |
