title: Fabrication of high-quality single-crystal Cu thin films using radio-frequency sputtering.
abstract: Copper (Cu) thin films have been widely used as electrodes and interconnection wires in integrated electronic circuits, and more recently as substrates for the synthesis of graphene. However, the ultra-high vacuum processes required for high-quality Cu film fabrication, such as molecular beam epitaxy (MBE), restricts mass production with low cost. In this work, we demonstrated high-quality Cu thin films using a single-crystal Cu target and radio-frequency (RF) sputtering technique; the resulting film quality was comparable to that produced using MBE, even under unfavorable conditions for pure Cu film growth. The Cu thin film was epitaxially grown on an Al2O3 (sapphire) (0001) substrate, and had high crystalline orientation along the (111) direction. Despite the 10(-3) Pa vacuum conditions, the resulting thin film was oxygen free due to the high chemical stability of the sputtered specimen from a single-crystal target; moreover, the deposited film had >5× higher adhesion force than that produced using a polycrystalline target. This fabrication method enabled Cu films to be obtained using a simple, manufacturing-friendly process on a large-area substrate, making our findings relevant for industrial applications.
authors.affiliation: 1] The Institute of Basic Science, Korea University, Seoul, 136-713, Republic of Korea [2].
authors.forename: Seunghun
authors.initials: S
authors.lastname: Lee
authors.affiliation: 1] Department of Nano Fusion Technology, Pusan National University, Miryang, 627-706, Republic of Korea [2].
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Kim
authors.affiliation: KAIST Analysis center for Research Advancement, Daejeon, 305-701, Republic of Korea.
authors.forename: Tae-Woo
authors.initials: TW
authors.lastname: Lee
authors.affiliation: Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706, Republic of Korea.
authors.forename: Won-Kyung
authors.initials: WK
authors.lastname: Kim
authors.affiliation: Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706, Republic of Korea.
authors.forename: Bum-Su
authors.initials: BS
authors.lastname: Kim
authors.affiliation: Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706, Republic of Korea.
authors.forename: Ji Hun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Busan center, Korea Basic Science Institute, Busan, 618-230, Republic of Korea.
authors.forename: Jong-Seong
authors.initials: JS
authors.lastname: Bae
authors.affiliation: Crystal Bank Research Institute, Pusan National University, Miryang 627-706, Republic of Korea.
authors.forename: Yong Chan
authors.initials: YC
authors.lastname: Cho
authors.affiliation: Department of Physics, University of Ulsan, Ulsan, 680-749, Republic of Korea.
authors.forename: Jungdae
authors.initials: J
authors.lastname: Kim
authors.affiliation: Fundamental and Creativity Research Division, Korea Electrotechnology Research Institute, Changwon-si, 642-120, Republic of Korea.
authors.forename: Min-Wook
authors.initials: MW
authors.lastname: Oh
authors.affiliation: Department of Materials Science and Engineering and Inter-University Semiconductor Research Center, Seoul National University, Seoul, 151-744, Republic of Korea.
authors.forename: Cheol Seong
authors.initials: CS
authors.lastname: Hwang
authors.affiliation: Department of Cogno-Mechatronics Engineering, Pusan National University, Miryang, 627-706, Republic of Korea.
authors.forename: Se-Young
authors.initials: SY
authors.lastname: Jeong