Date: 21/02/2012

Building nanoscale transistors by aligning atoms, a disruptive tech for litho equipment

Researchers are attempting to find new techniques to build electronic devices without etching process. These new ideas can produce new disruptive systems which can throw the present lithography based semiconductor chip making equipment to scrap. In today's world a 28nm semiconductor fab is 5Billion$ (approx) of investment. Equipments in these fabs etch the silicon at line width of few tens of nanometers using extreme precision machinery. Instead of etching nearly atomic scale patterns on a semiconductor material, why not align atoms to form atomic scale conductors, semiconductors and insulators in the same device.

The team of researcher from the University of New South Wales, Melbourne University and Purdue University are building few-atoms thick electrical conductors on a silicon material to interconnect the devices on the chip instead of presently used copper wires. If this research uses less complex equipment than the litho tools, along with the increase in integration as per Moore's law it may also bring the fab cost down. Clearly a disruptive technology.

This atomic-scale wire concept is said to follow the well known ohm's law of relationship between voltage, current and resistance.

Gerhard Klimeck, a Purdue professor of electrical and computer engineering and director of the Network for Computational Nano-technology says "Typically we chip or etch material away, which can be very expensive, difficult and inaccurate. Once you get to 20 atoms wide you have atomic fluctuations that make scaling difficult. But this experimental group built devices by placing atomically thin layers of phosphorus in silicon and found that with densely doped phosphorus wires just four atoms wide it acts like a wire that conducts just as well as metal."

This research is aimed to develop future quantum computers in which single atoms are used for the computation, says Michelle Simmons, director of the Centre of Excellence for Quantum Computation and Communication Technology at the University of New South Wales and the project's principal investigator. He adds "We are on the threshold of making transistors out of individual atoms, But to build a practical quantum computer we have recognized that the interconnecting wiring and circuitry also needs to shrink to the atomic scale."

Finally what matters is how much time it takes from labs to production floor.