Magnetoresistance of high quality graphene devices
Ching-Ya Cheng1*, Ku-Yu Chen1, Chung-Jen Chung2, Chung-Lin Wu1, T.M.Chen1
1Department of Physics, National Cheng Kung University, Tainan 701, Taiwan
2Center for Micro/Nano Science and Technology, National Cheng Kung University, Tainan 701, Taiwan
* presenting author:鄭敬亞, email:samu172004@gmail.com
Graphene devices on standard SiO₂/Si substrates are facing a bottleneck. These kind of devices can only show the primary characteristics of graphene, and is far away from exhibiting some intrinsic properties and beautiful physics of graphene. If one wants to improve the quality of the devices, one has to find other insulators to replace SiO₂ as the substrate of graphene. Although there have been great successes on improving graphene devices by using the boron nitride substrates¹, the fabrication of boron nitride substrates are difficult. This make it impossible for massive production.

Here we choose β-Si₃Ni₄ as the new substrate for graphene, because theoretical calculations suggest that the quality of graphene would be largely improved if being on β-Si₃Ni₄². The β-Si₃Ni₄ can be grew directly on Si wafer, which is its advantage, and is expected to improve graphene quality as much as boron nitride. We create graphene by the mechanical exfoliation method, and the electron-beam lithography was used to fabricate the hall bar. The magnetoresistance, particularly focusing on the quantum Hall effect, mobility, etc, is being measured at low temperature down to 1.5K.

Reference:
1. C. R. Dean. et al. Boron nitride substrates for high-quality graphene electronics. Nature Nanotechnology 5, 722–726 (2010)
2. Ming Yang, Chun Zhang, Shijie Wang, Yuanping Feng, and Ariando. Graphene on β-Si3N4: An ideal system for graphene-based electronics. AIP Advances 1, 032111 (2011)


Keywords: Graphene, β-Si₃Ni₄, Quantum Hall effect