| 학회 | 한국재료학회 |
| 학술대회 | 2020년 가을 (11/18 ~ 11/20, 휘닉스 제주 섭지코지) |
| 권호 | 26권 1호 |
| 발표분야 | 특별심포지엄8. 첨단신소재 응용 및 분석기법 심포지엄-오거나이저: 조형균(성균관대), 정후영(UNIST) |
| 제목 | Advanced materials for the future heterointegrated system via remote epitaxy technologies |
| 초록 | The growth of various epitaxy materials is limited by crystal structure and lattice mismatch although high-quality single-crystalline thin films can be formed onto the substrate via conventional epitaxy technique. In addition, conventional heteroepitaxy of lattice-mismatched systems generates dislocations to release the strain energy between epilayer and substrate. Since the formation of dislocations in the epilayer degrades device performance, it is essential to control the formation and growth of defects. Here, we demonstrate the role of a graphene layer that allows the heteroepitaxy materials of the highly mismatched systems with reduced dislocation density.[1] Van der Waals field generated onto graphene film effectively controls ionic force between the seed atoms of epilayer and substrate at the early stage of growth, which enables spontaneous relaxation of the epilayer before the accumulated elastic energy created by the lattice mismatch induces misfit dislocations. From the system with a small lattice mismatch, we observed that conventional heteroepitaxy gradually relaxes the misfit train via the introduction of dislocation, while heteroepitaxy on graphene-coated substrates abruptly relaxes the strain in the epilayer via interface displacement on the graphene's slippery surface. This effect becomes more prominent in a highly mismatched system, where a substantially reduced dislocation density is seen. The spontaneous relaxation technique could enable the monolithic integration of largely lattice-mismatched systems with minimized dislocation density, which could eventually broaden the material spectrum for advanced electronics and photonics. Also, this innovative technique is successfully applied to the heterogeneous integration of single-crystalline complex-oxide membranes.[2] The combination of remote heteroepitaxy and engineered heteroepitaxy with the buffer layer establishes a platform for the future stacking three-dimensional structure.[3] [1] Nature Nanotechnology 15, 272-276(2020) [2] Nature 578, 75-81(2020) [3] This work was supported by the faculty research fund of Sejong University in 2020. |
| 저자 | 김성규 |
| 소속 | 세종대 |
| 키워드 | epitaxy; remote epitaxy; graphene; heterointegration |
