Silicon Replacement: Gallium Arsenide?

Gallium arsenide (GaAs), an expensive but highly efficient semiconductor, is being studied by researchers at the University of Illinois at Urbana-Champaign to develop more efficient [than silicon] and surprisingly cheaper devices including solar cells and infrared cameras. This semiconductor can potentially increase speeds of computer chips making your computing experience more enjoyable.

The key to electronic devices is always the chip that runs it, and the chip is made from a wafer. A wafer is a thin slice of semiconductor used to create complicated circuits and other devices. Wafers are made from a highly purified material, typically silicon (99.999 percent-plus pure), and they have a nearly perfect crystalline structure. However, the problem with silicon wafers is their size which can crack if too thin. So when a larger diameter semiconductor is needed, the thickness of the wafer must also increase, increasing cost. Finally, since the wafers are cut from a larger structure using a fine wire saw, there can often be imperfections in the surface which must be chemically treated, also increasing cost.

The researchers, led by John Rogers, have created a technique that involves growing stacks of thin films of semiconductor onto a wafer and then taking each individual film off one by one and placing it onto a cheaper substrate or "base" to support the ultra thin (hundreds of nanometers to a few micrometers) film. The benefit of this process is that it eliminates excess material thickness for larger diameter wafers meaning that it's cheaper, and it's also more efficient.

Roger's group has successfully used this technique to "build devices -- including transistors, solar cells and infrared cameras -- on the substrates, leaving the wafer intact and ready for a new batch of film." The technique may be applied to computer chip manufacturing which will lower the cost and increase the speed of your computer!

[Via ieee spectrum]

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