APPLICATIONS OF TECHNOLOGY:
- Semiconductor device manufacturing
- Scalable manufacturing process
- Single pass simplicity
- Suitable for precision patterning
Yuegang Zhang and a team of Berkeley Lab scientists have developed a single-step chemical vapor deposition (CVD) process that can bond a single layer of graphene onto a dielectric surface such as sapphire or silicon oxide. This is a significant step needed for industrial-scale production of graphene semiconductors. Electronic devices that exploit the extraordinary properties of graphene will offer high switching speeds and ultralow power consumption.
Graphene layers can be grown on copper, but not on insulating surfaces such as silicon oxide or sapphire. The Berkeley Lab technology overcomes this limitation by manipulating graphene into binding with an insulating surface using a modified method of CVD, a scalable process widely used in semiconductor manufacturing.
The process is accomplished in a single pass through the CVD chamber. First, a thin film of copper is deposited onto sapphire, silicon oxide, or a similar insulating surface. The materials are placed inside the chamber, where a graphene layer is grown on top of the copper. Then the copper foundation is boiled away, lowering the graphene layer until it binds firmly to the insulating surface. With further refinements, lithographic techniques can be used to grow the graphene in precise patterns that form electronic devices suitable for large-scale manufacturing.
Alternative approaches, such as deposition of graphic oxide or exfoliated graphite, cannot control the number of graphene layers, degrading their high conductivity. Another technique, mechanical cleavage of graphite, works under laboratory conditions but is not suitable for large-scale manufacturing. Vacuum annealing of silicon carbide, which has shown more promise, requires very expensive materials and equipment.
STATUS: Issued U. S. Patent 8,709,881. Available for licensing or collaborative research.
DEVELOPMENT STAGE: Bench scale prototype.
FOR MORE INFORMATION:
Ismach, A., Druzgalski, C., Penwell, S., Schwartzberg, A., Zheng, M., Javey, A., Bokor, J., Zhang, Y. “Direct Chemical Vapor Deposition of Graphene on Dielectric Surfaces,” Nano Letters 10: 1542-1548 (2010).
Yarris, L. “Graphene Film Clears Major Fabrication Hurdle,” Berkeley Lab News Center, April 8, 2010.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
Orderly Deposition of Uncontaminated Graphene, IB-2672
Tunable Graphene Electronic Devices, JIB-2697
REFERENCE NUMBER: JIB-2758