Low-temperature epitaxy of transferable high-quality Pd(111) films on hybrid graphene/Cu(111) substrate
- 80 Downloads
The continuous pursuit of miniaturization in the electronics and optoelectronics industry demands all device components with smaller size and higher performance, in which thin metal film is one heart material as conductive electrodes. However, conventional metal films are typically polycrystalline with random domain orientations and various grain boundaries, which greatly degrade their mechanical, thermal and electrical properties. Hence, it is highly demanded to produce single-crystal metal films with epitaxy in an appealing route. Traditional epitaxy on non-metal single-crystal substrates has difficulty in exfoliating away due to the formation of chemical bonds. Newly developed epitaxy on single-crystal graphene enables the easy exfoliation of epilayers but the annealing temperature must be high (typical 500–1,000 °C and out of the tolerant range of integrated circuit technology) due to the relative weak interfacial interactions. Here we demonstrate the facile production of 6-inch transferable high-quality Pd(111) films on single-crystal hybrid graphene/Cu(111) substrate with CMOS-compatible annealing temperature of 150 °C only. The interfacial interaction between Pd and hybrid graphene/Cu(111) substrate is strong enough to enable the low-temperature epitaxy of Pd(111) films and weak enough to facilitate the easy film release from substrate. The obtained Pd(111) films possess superior properties to polycrystalline ones with ~ 0.25 eV higher work function and almost half sheet resistance. This technique is proved to be applicable to other metals, such as Au and Ag. As the single-crystal graphene/Cu(111) substrates are obtained from industrial Cu foils and accessible in meter scale, our work will promote the massive applications of large-area high-quality metal films in the development of next-generation electronic and optoelectronic devices.
Keywordssingle-crystal metal film graphene/Cu(111) substrate interfacial interactions meter scale
Unable to display preview. Download preview PDF.
This work was supported by the National Key R&D Program of China (Nos. 2016YFA0300903 and 2016YFA0300804), the National Natural Science Foundation of China (NSFC) (No. 11888101), the National Equipment Program of China (No. ZDYZ2015-1), Beijing Graphene Innovation Program (No. Z181100004818003), Beijing Municipal Science & Technology Commission (No. Z181100004218006), Bureau of Industry and Information Technology of Shenzhen (Graphene platform contract NO. 201901161512), and the Key R&D Program of Guangdong Province (No. 2019B010931001).
- Matthews, J. W. Epitaxial Growth. Elsevier: Amsterdam, 1975.Google Scholar