Nanowire Channels Used for Next Generation of Chips

Despite the fact that gallium arsenide is one of the most versatile materials to be used for electronics, a series of challenges prevents the wide-scale introduction of nanowire channels in existing electronic devices. However, all that is about to change, as researchers at the University of Illinois have recently developed the first metal-semiconductor, field-effect transistor, which has been constructed with a self-assembled, planar gallium-arsenide nanowire channel.

Details of the new transistor construction technique will be detailed in an upcoming issue of the scientific journal Electron Device Letters, published by the Institute of Electrical and Electronics Engineers (IEEE). In charge of the research have been Xiuling Li, who is a University of Illinois electrical and computer engineering professor, and Seth Fortuna, a UI graduate research assistant.

They studied nanowires on account of the large range of applications they could be used for, from electronics to the field of photonics, and because a breakthrough in this field could revolutionize the way everything from computers to chips was made.

“Our new planar growth process creates self-aligned, defect-free gallium-arsenide nanowires that could readily be scaled up for manufacturing purposes. It's a non-lithographic process that can precisely control the nanowire dimension and orientation, yet is compatible with existing circuit design and fabrication technology,” Li, who is also affiliated with the Beckman Institute, explained.

“By replacing the standard channel in a metal-semiconductor field-effect transistor with one of our planar nanowires, we demonstrated that the defect-free nanowire's electron mobility was, indeed, as high as the corresponding bulk value. The high electron mobility nanowire channel could lead to smaller, better and faster devices,” Fortuna said.

The nanowire channels were created using chemical vapor deposition (CVD), and gold was used as a catalyst for the chemical reactions. During CVD, volatile precursors of the desire materials are placed on a substrate (wafer), where they react and decompose, eventually leaving behind a very thin and pure film of the substance the researchers want to produce. The process can be used to produce everything from silicon, carbon fiber, and carbon nanofibers, to filaments and carbon nanotubes.