Effects of pressure, temperature, and hydrogen during graphene growth on SiC(0001) using propane-hydrogen chemical vapor deposition

Abstract

Graphene growth from a propane flow in a hydrogen environment (propane-hydrogen chemical vapor deposition (CVD)) on SiC differentiates from other growth methods in that it offers the possibility to obtain various graphene structures on the Si-face depending on growth conditions. The different structures include the (6√3 × 6√3)-R30° reconstruction of the graphene/SiC interface, which is commonly observed on the Si-face, but also the rotational disorder which is generally observed on the C-face. In this work, growth mechanisms leading to the formation of the different structures are studied and discussed. For that purpose, we have grown graphene on SiC(0001) (Si-face) using propane-hydrogen CVD at various pressure and temperature and studied these samples extensively by means of low energy electron diffraction and atomic force microscopy. Pressure and temperature conditions leading to the formation of the different structures are identified and plotted in a pressure-temperature diagram. This diagram, together with other characterizations (X-ray photoemission and scanning tunneling microscopy), is the basis of further discussions on the carbon supply mechanisms and on the kinetics effects. The entire work underlines the important role of hydrogen during growth and its effects on the final graphene structure.

Magnetoresistance of disordered graphene: From low to high temperatures

“…[24,25] Depending on the growth conditions, either the samples are hole-doped and the graphene lies on a hydrogen-passivated SiC surface, or they are n-doped and the graphene lies on a carbon-rich buffer layer. [26,27].…”

Vertical Transistors Based on 2D Materials: Status and Prospects

“…However, to date, high quality Gr growth has been demonstrated only on a few semiconducting or semi-insulating materials, such as silicon-carbide [38][39][40]111,112] and, more recently, germanium [113]. Single or few layers of Gr can be obtained on the Si face (0001) of hexagonal SiC, either by controlled sublimation of Si at high temperatures (typically > 1650 • C) in Ar at atmospheric pressure or by direct CVD deposition at lower temperatures (~1450 • C) using an external carbon source (such as C 3 H 8 ) with H 2 or H 2 /Ar carrier gases [111].…”

Combining graphene with silicon carbide: synthesis and properties – a review

“…Up to this moment we considered only the literature reports devoted to propane-argon assisted growth, but there is also some interesting experimental data on CVD growth of graphene by using hydrogen as a carrier gas [114,126,129,131,132,136]. Michon et al [114,126,129] demonstrated the possibility of direct growth of graphene on 6H-SiC (0001) and 3C-SiC/Si substrates. It was concluded that the increase in propane flow in propane-hydrogen gas mixture leads to a significant decrease in the SiC etching rate and increase in graphene thickness.…”

“…The most widely studied among the carbon sources is propane [114,121,124,126,[128][129][130][131][132][133][134][135][136][137]. There is only a few works devoted to ethene [125], toluene [127] and xylene [127] as carbon sources for graphene growth on silicon carbide.…”

“…There is a lot of excellent reports in literature dealing with deposition of graphene from external sources on metallic surfaces (Cu, Ni, Ir, etc) and on dielectric wafers (SiC, sapphire, Si, etc.). Following the main purpose of this review paper, we focus only on the CVD and MBE growth of graphene on silicon carbide [114,121,[123][124][125][126][127][128][129][130][131][132][133][134][135][136][137][138][139][140][141]. Therefore, the aim of this subsection is twofold: (i) to understand the main difference between thermal decomposition of silicon carbide and bottom-up growth of graphene on SiC and (ii) to extensively review the literature concerning the CVD and MBE growth processes with participation of SiC substrate.…”