Silicon is so important for electronics and computer science that it has become synonymous with technology. Hence why the most important place for technology in the United States is called Silicon Valley.
Now, scientists have created a way to manufacture super pure silicon chips that could pave the way for more stable quantum computers.
Superpure chips will allow the creation of quantum computers
Silicon is the preferred material for electronics for several reasons. First, it is a semiconductor, which means it can conduct electricity at different levels under different conditions. Additionally, being the second most abundant element in the Earth’s crust, it is not difficult to obtain.
This has worked well for decades, fueling the incredible expansion of computers, but for more advanced systems, the purity of silicon becomes a limiting factor.
Quantum bits (qubits) that process and store information can lose their “coherence” with the slightest interference, such as a small temperature fluctuation or impurity in the silicon.
“The problem is that, while natural silicon is mostly the desirable isotope silicon-28, there is also about 4.5% of silicon-29,” explains professor David Jamieson, co-supervisor of the project. “Silicon-29 has an extra neutron in the nucleus of each atom that acts like a small magnet, destroying quantum coherence and creating computer errors.”
That’s why, for the new study, researchers from the University of Melbourne and the University of Manchester developed a way to manufacture much purer silicon.
The team used a machine called an ion implanter to shoot a beam of silicon-28 at a computer chip, gradually replacing the silicon-29 impurities in the chip with the more desirable silicon-28. The end result was that the silicon-29 content was reduced from 4.5% to just 0.0002%, which is two parts per million.
“The great news is that to purify silicon to this level, we can use a standard machine (an ion implanter) that is found in any semiconductor manufacturing laboratory, adjusted to a specific configuration that we have designed,” explains Jamieson.
The more qubits a quantum computer has, the more powerful it will be, but also more vulnerable to errors. These new ultra-pure silicon chips should help quantum computers with many qubits stay stable for longer, and the team claims that the next step is to test it.
