*Ping-Yen Hsieh, Jonathan Ho, Ying-Hung Chen, Ju-Liang He, Feng Chia University, Taichung City, Taiwan
Hetero-growth of graphene film onto semiconductor materials is a dream for the development of graphene-based electronic devices, yet unachievable so far. Since graphene film prepared on copper foil by using high power impulse magnetron sputtering (HIPIMS) at relative low temperature of 600oC has been successfully demonstrated in our previous study, herein an approach to grow graphene film on silicon substrate by incorporating copper using the second HIPIMS powered copper target prior to and/or during graphene growth was studied. As a result of the study, the HIPIMS pre-deposited ultra-thin copper film (UTCF) was obtained with an atomic level of surface smoothness, which act as a catalyst layer to facilitate graphene growth. Without the pre-deposited UTCF, only amorphous carbon is obtained. Further successive incorporating copper during HIPIMS-graphene growth stage, it is interesting to observe that graphene grow thicker, whilst no copper element was detected in the deposited graphene layer. It is believed that the UTCF re-evaporate at all time, resulting in copper-free graphene that heterolytically grow onto silicon. Copper, in this regard, even in the gas phase state can serve to catalyze graphene growth. Mechanism of such a successful hetero-growth of HIPIMS-graphene on silicon substrate was discussed adequately in this report. This method bears great potential in future graphene electronic applications.