SIMIT Made Important Progress in Germanium-assisted Growth of Graphene Material on Insulators
Recently, the SOI (Silicon on insulator) Materials and Devices Research Group of the State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, made important progress in the research on the preparation of graphene directly on the insulating substrates. The preparation of graphene on insulator is an important basic condition to promote the application of graphene in the field of microelectronics. In response to this demand, the SOI Materials and Devices Research Group researchers used germanium thin films as catalysts and successfully prepared high-quality monolayer graphene material on silicon dioxide, sapphire, quartz glass and other insulating substrates by the chemical vapor deposition (CVD) method, and applied it in the demister and other electric heating devices successfully. The related research findings were published in the recent issue of the journal "Small" (DOI: 10.1002/smll.201700929), entitled "Germanium-assisted Direct Growth of Graphene on Arbitrary Dielectric Substrates for Heating Devices". Article link: http://onlinelibrary.wiley.com/doi/10.1002/smll.201700929/full.
Graphene has received wide attention from the academic community due to its excellent physical properties. To achieve its application in the field of microelectronics, graphene film needs to be transferred to or directly grown on the insulation substrates. The direct growth of graphene on insulating substrates is conducive to obtaining wafer grade graphene material, which is of great significance to promote the application of graphene material in the integrated circuit and other fields. However, as the insulating substrate itself does not have the catalytic ability, the use of Cu (Copper), Ni (Nickel) and other metal catalysts will inevitably lead to metal contamination, the research has been faced with many challenges. Wang Ziwen, Xue Zhongying et al. of the State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences pre-deposited germanium film on the insulating substrate as the catalyst based on the study on the growth of high quality monolayer graphene on germanium substrates, and realized full coverage of monolayer graphene on the insulating substrate surface while completely evaporating the germanium film at the same time by optimizing the growth temperature and growth time of graphene. In the study, they also found that the shape of graphene was completely dependent on the shape of the germanium film. Therefore, the method not only can achieve the growth of wafer-grade graphene film, but also can define the subsequent required graphical growth of graphene devices through pre-designed germanium pattern. The obtained graphene material on the insulators showed good electrical properties, demonstrating its preliminary application in the aspect of defogging, electrochromic and other heating elements. This study has laid a foundation for obtaining graphene on wafer-level insulators, which is conducive to promoting the application of graphene materials in the field of microelectronics.
This work is sponsored by the Young Top-notch Talent Project, Key Frontier Scientific Research Projects of the Chinese Academy of Sciences and the Program of Shanghai Subject Chief Scientist.
Fig. 1 Preparation process and experimental results of germanium-assisted growth of graphene on insulators
Fig. 2 Electrochromic devices prepared on the graphene / quartz glass substrates and the performance characterizations