CVD Graphene Films on Silicon and Silicon Dioxide

This article describes the properties and applications of Graphenea's range of CVD graphene films on silicon and silicon dioxide substrates.

Monolayer Graphene Film on SiO₂/Si

Monolayer graphene is produced using the CVD process on a copper catalyst and then transferred to a SiO₂/Si substrate through the wet transfer process. The product is suitable for universities and research and development departments. This high quality graphene product is ideal for research and product R&D applications.

• 4" Wafer
• 1 cm x 1 cm
• 1 inch x 1 inch (25mm x 25mm)
• 10mm x 10mm

Figure 1. Monolayer graphene on SiO₂/Si (4" wafer)

Figure 2. Monolayer graphene on SiO₂/Si (1 cm x 1 cm)

Figure 3. Monolayer graphene on SiO₂/Si (1” x 1”)

Bilayer Graphene on SiO₂/Si (non AB Bernal Stacking)

The bilayer graphene product includes two CVD monolayers which are created through multiple transfers on a SiO₂/Si substrate. Compared to monolayer graphene samples, it is possible to obtain lower sheet resistance values. If required, the bilayer graphene can be prepared on other substrate materials such as quartz and PET.

Figure 4. Bilayer graphene on SiO₂/Si (10mm x 10mm)

Trilayer Graphene on SiO₂/Si (non AB Bernal Stacking)

The trilayer graphene product includes three CVD monolayers that are created through multiple transfers on a SiO₂/Si substrate. It is possible to achieve lower sheet resistance values than with monolayer graphene samples.

However, in trilayer graphene film, the impurity levels will be relatively high when compared to the monolayer film as a result of the multiple transfer processes.

Figure 5. Trilayer graphene on SiO₂/Si (10mm x 10mm)

Features of Graphene Films

The key features of graphene films are as follows:

• Thickness (theoretical): 0.345nm (thickness is 0.69 and 1.035nm in bilayer and trilayer graphene products, respectively)
• Hall electron mobility on SiO₂/Si: 4000cm²/Vs
• FET electron mobility on Al₂O₃: 2000cm²/Vs
• Grain size: Up to 10µm
• Sheet resistance: 450±40Ω/sq (1cm x1cm) (330±30/sq (1cm x 1cm) in case of bilayer graphene product)
• Transparency: >97 % (transparency is >94% and >92% in bilayer and trilayer graphene products, respectively)
• Coverage: >95%

Features of SiO₂/Si Substrate

• Thickness: 525 +/- 20µm (thickness is 525 +/- 25µm in trilayer graphene)
• Dry oxide thickness: 300nm (+/-5%)
• Resistivity: <0.005Ω•cm (resistivity is 1 to 30Ω•cm in trilayer graphene)
• Orientation: <100>
• Type/dopant: P/Bor
• Particles: <[email protected]µm
• Front surface: Single side polished
• Back surface: Etched

Applications of Graphene Films

Graphene films are used in the following applications

• Graphene optoelectronics
• Transparent conductors in LEDs, OLEDs, solar cells, etc.
• Graphene research
• Graphene transistors and electronics applications
• Nanophotonics and plasmonics
• Bioelectronics and biosensors
• Graphene photodetectors (measure optical power or photon flux)
• MEMS and NEMS
• Aerospace industry (thermal interface materials, electronics, and so on)

Quality Control

Graphenea’s samples go through a stringent QC process to make sure that the graphene produced is of high quality and has excellent reproducibility. Each individual sample is inspected through Raman spectroscopy (I(G)/I(2D)<0.7; I(D)/I(G)<0.05), and optical microscopy to guarantee good transfer quality and purity. Graphenea also provides customized solutions for application requiring additional specific controls such as scanning electron microscopy (SEM) and atomic electron microscopy (AFM).

This information has been sourced, reviewed and adapted from materials provided by Graphenea.

For more information on this source, please visit Graphenea.