Growth And Structure Characteristic Of Graphene On The Substrates Of Si As Well As SiO₂/Si

Graphene is a new material, comprising of a monolayer of carbon atoms packed into a two-dimensional honeycomb lattice, exihibits a series of unusual mechanical, electrical and thermaldynamic properties and will be widely applied in integrated circuit, functional composite materials, energy storage materials, catalyst support etc. At present, many production methods of graphene have been developed, such as micromechanical cleavage, chemical stripping, metal substrate epitaxy, SiC thermal annealing, etc. However, the graphene prepared by these methods require special substrates or needs to be transferred to other insulative substrates due to their micro-electrical devices design and application, and it can not be used with the current Si-based semiconductor technology.In this theis, we explore to grow graphene films on the substrates of SiO₂/Si via directely depositing solid-state carbon atoms, moreover, synchrotron radiation (SR) experimental technology and some normal analysis methods have been employed for the structural charateristics of grown graphene films. The main results are listed as following:1) Graphene films were grown on Si(111) at different substrate temperature (400,600,700,800℃) by directly depositing solid-state carbon atoms. The structural properties are characterized by RHEED, FTIR, Raman and NEXAFS. The results indicated that: the films grown at 400, 600, 700℃temperature just contained amorphous carbon, only at the 800℃temperature graphene films started to form. Therefore, we thought that substrate temperature played a key role during the formation process of graphene grown on the Si substrates, meanwhile, the formation of a SiC buffer layer was helpful for the growth of graphene.2) Graphene films were grown on SiO₂/Si substrates at different substrate temperature (500, 600, 700, 900, 1100, 1200℃) by directly depositing carbon atoms. The structural properties are characterized by Raman, NEXAFS and XPS. The results indicated that: 700℃was the initial temperature for the formation of graphene,and 1100℃was the optimal temperature for the growth of graphene on SiO₂/Si substrate. The quality of graphene films improved with increasing the substrate temperature. However, when the substrate temperature was too high, the partial decomposition of the oxide layer would lead to the poor quality of the grown graphene films.