| 학회 | 한국재료학회 |
| 학술대회 | 2020년 가을 (11/18 ~ 11/20, 휘닉스 제주 섭지코지) |
| 권호 | 26권 1호 |
| 발표분야 | 특별심포지엄5. 차세대 디스플레이 기술을 위한 나노/마이크로 LED 심포지엄-오거나이저: 이인환(고려대), 홍영준(세종대) |
| 제목 | Wafer-Scale Formation of metallic van der Waals Electrodes with Ideal Schottky Barriers for Two-Dimensional Nanoelectronics |
| 초록 | Beyond the silicon and compound semiconductor industries, two-dimensional van der Waals (2D vdW) materials have been predicted to be able to revolutionize electronics, photonics, and other industrial sectors since they possess many fascinating physical and electrical properties. However, 2D materials currently face challenges along the long-term road to commercialization, with increasing efforts being made to satisfy industrial needs. At this moment, the most critical issue for final 2D device performance is related to realizing good electrical contacts to 2D vdW semiconductors. In fact, most 3D (bulk) metals form non-Ohmic Schottky junctions to 2D vdW semiconductors, resulting in relatively high and bias-dependent contact resistances. Furthermore, the Fermi level at the metal-semiconductor junction (MSJ) is often pinned owing to several types of chemical interactions, and the Schottky-Mott rule generally provides incorrect prediction for the Schottky barrier height (SBH). In this study, we not only performed the wafer-scale production of patterned transition metal (TM) ditellurides (e.g., WTe2 or MoTe2) on desired surfaces and positions with high electrical performance but also demonstrated the experimental formation of monolayer MoS2 FETs containing 2D WTe2/MoS2 vdW MSJs with almost perfect interfaces. We have designed simple and efficient methods to grow high-quality, stoichiometric TM ditellurides with electrical performances comparable to those of mechanically exfoliated flakes. The fabricated 2D (W, Mo)Te2/monolayer MoS2 vdW MSJs with close-to-perfect interfaces are free from significant disorder effects and Fermi level pinning on the interface, and their SBHs largely follow the trend of the Schottky-Mott limit. For example, the measured SBH (≈103.5 meV) of the WTe2/MoS2 interface was the lowest value experimentally observed for metal electrodes formed on monolayer MoS2 and was very close to the theoretical value (≈100 meV) calculated by the Schottky–Mott rule. Compared to the MSJs with conventional 3D metals, the fabricated 2D WTe2/MoS2 vdW MSJs exhibited a much improved electrical injection across the MSJs, which was attributed to the low SBH and depinning of the Fermi level at the interface. Employing position-controlled, patterned vdW contacts with ideal Schottky barriers provides the advantage of controlling the SBHs in a predictable manner. This ability to fabricate position-controlled, conformal vdW metals with different shapes affords new possibilities for the fabrication of multiple 2D nanoelectronics devices |
| 저자 | 권순용 |
| 소속 | 울산과학기술원 (UNIST) |
| 키워드 | two-dimensional van der Waals materials; transition metal ditellurides; nanoelectronics |
