Some obstacles to this process still remain

Nov 5, 2009 10:04 GMT  ·  By

Semiconductor chips, which could be rightfully dubbed the “backbone” of modern society, are at the very foundation of a number of electronic devices including microchips and other circuits. They essentially keep the world moving today and are of invaluable use to humans in most aspects of life. In spite of them being so widespread, they are not the fastest such equipments on the block. For the last 30 years, experts have been tinkering with gallium arsenide, a material that they say could replace silicon as the preferred substrate for semiconductors, LiveScience reports.

The advantage that gallium has over silicon can be summed up in three simple words – higher electron mobility. Gallium arsenide is a special type of the chemical that is even more suited to carrying electrical impulses. Because the electrons move faster within this chemical, they can get from point A to point B faster than the electrons in silicon can. For real-life applications, this is like comparing a Steam-engine locomotive with a fast, modern train, traveling at several times its speed.

This hypothetical speed can also be augmented by using not only the silicon replacement, but a three-way combination of the rare, silvery metal known as indium, gallium and arsenic, a renowned poison that, in semiconductors, acts as a hardening agent. According to University of Texas materials scientist Christopher Hinkle, this combination can result in transistors that are ten times faster than any existing one. Combining gallium arsenide-based substrates with the carbon compound graphene may lead to even higher speeds, although this field of research is still in its infancy. Graphene was only discovered in 2004, at the University of Manchester, in the United Kingdom.

“We have already made transistors using the indium-gallium-arsenic material, and they are right around 10 faster than silicon ones. But they have an order of magnitude more defects, making them less reliable, and they break down faster,” Hinkle adds. Replacing silicon with gallium is “harder than it sounds – the whole process has not been completely solved,” the expert adds. He will present the finds between November 8-13, in San Jose, at the 56th annual International Symposium & Exhibition of the American Vacuum Society.