| AVS 61st International Symposium & Exhibition | |
| 2D Materials Focus Topic | Monday Sessions |
| Session 2D+AS+EM+NS+SS-MoA |
| Session: | Dopants, Defects, and Interfaces in 2D Materials |
| Presenter: | KiSeok Kim, Sungkyunkwan University, Republic of Korea |
| Authors: | K.S. Kim, Sungkyunkwan University, Republic of Korea G. Yeom, Sungkyunkwan University, Republic of Korea |
| Correspondent: | Click to Email |
Recently, graphene has been widely investigated due to the superior electrical, mechanical, thermal, and chemical properties. Especially, CVD graphene which was grown on Cu foil and transferred to various substrates using PMMA has been used most widely due to the possible large area applications such as electronic devices for displays, semiconductors, etc. However, in order to apply the transferred CVD graphene to the various electronic device fabrication, PMMA residue on the graphene surface formed during the transfer process and lithography process needs to be completely removed without damage. Various methods have been investigated to remove the residue on the graphene surface such as current cleaning, heat treatment, chemical cleaning, etc. However, it is reported that these methods are not effective in removing the residue on graphene or not applicable to industry.
In this study, a controlled Ar ion beam has been used to effectively remove the PMMA residue on graphene surface. By controlling the Ar ion beam condition, the residue on graphene surface could be removed while minimizing the damage on the graphene surface. Especially, by lowering the Ar beam energy less than 10 eV, it was possible to effectively remove the PMMA residue without damaging the graphene. The removal of PMMA residue on the graphene surface could be identified using Raman Spectroscopy showing the red shift of 2D peak (2670 cm-1) and blue shift of G peak (1580 cm-1) in addition to the decrease of RMS roughness from 1.3nm to 0.3 nm using an AFM (Atomic Force Microscopy). The effectiveness of graphene cleaning was also confirmed by XPS (X-ray Photoelectron Spectroscopy), by the uniform deposition of ALD HfO2 layer on the cleaned graphene surface, by measuring the electrical properties of deposited ALD HfO2, etc.