Single-Step Direct Growth of Large-Area Graphene and Graphene-Based Nanostructures on Silicon by Plasma-Enhanced Chemical Vapor Deposition (PECVD)

Chemical vapor deposition (CVD) of graphene on metallic substrates (e.g., Cu, Ni) at high temperatures (~ 1000 C) has been the most common process for large-scale synthesis of graphene. However, high-temperature growth processes are incompatible with CMOS technology. Moreover, the synthesis of graphene on metallic substrates requires additional sample transfer processes to semiconductor substrates, which often result in degradation of the sample quality. Therefore, it is highly desirable to explore direct growth of graphene on silicon for better integration of graphene into current semiconductor industry. In this study, we demonstrate the feasibility of a single-step method for direct growth of large-area graphene and graphene-based nanomaterials on silicon by means of PECVD without active heating. By proper control of the PECVD growth parameters, we can obtain a variety of graphene-based materials, including large-area graphene flakes, graphene sheets, and vertically grown graphene nanostripes. Correlation between the growth recipes and the resulting sample characteristics is made by studying the Raman spectroscopy, XPS, UPS, SEM and AFM, which helps unveil the growth mechanism and optimize the growth quality of graphene on silicon.