Silicon Spintronics Possible At 225ºC Too

Scientists at the U.S. Naval Research lab have demonstrated that spin accumulation in silicon is viable at high ambient temperatures in the range of 200-300ºC. Spintronics is a relatively nascent field with many unexplored avenues. For starters, let us first understand what spintronics is exactly. It involves the use of the electron spin of the valence electrons in semiconductor materials like silicon and germanium as the governing force for current instead of electron charge. This technology will help to develop high performance #-Link-Snipped-#semiconductor devices that will be much faster, reliable, low energy consuming and with lower levels of power dissipation. The Materials Science and Technology department researchers have now observed and experimentally proven that this process of electrical injection, detection and spin accumulation in Si at 225ºC is possible and can be achieved with a little modification to the earlier approach. This important revelation implies that Silicon can be used to develop reliable practical spintronic devices which fulfil the operating temperature specifications for industrial (100°C), commercial (85°C) and military (125°C) applications. The findings and conclusions of this research titled "Electrical injection and detection of spin accumulation in silicon at 500K with magnetic metal / silicon dioxide contacts" will be available in the March 22^nd 2011 printed edition of the Nature Communications.

According to the thesis, the electrons are having a type of angular momentum called the spin which is internal in nature. It can be used as a new state variable as declared by the International Technology Roadmap for Semiconductors. The electron spin can be used as a replacement for the electron’s charge and has a scope beyond the famous Moore’s law. The law has been named after Intel co-founder Gordon E. Moore who prophesized that the transistor density per unit area in an integrated circuit would double approximately every two years as developments in fabrication technology helped smaller devices to be manufactured. Moore predicted this way back in 1965 and was proven right till now. But today, the critical dimensions of devices are measured in atomic length scales so size reduction is becoming difficult. So, now it’s the time to use spin as an alternative solution for next generation electronics.

Naval Research Laboratory scientists Connie Li, Olaf van 't Erve and Jonker electrically generated and detected spin accumulation and precession in the silicon transport channel at temperatures up to 225°C. They came to the deduction that the data or knowledge regarding the spin parameter can be sent in the silicon substrate over distances readily compatible with existing fabrication technology. They have thus achieved great deal of success in achieving control over the spin state variable in heated environments normally present in industries and factories.

Image Credit: The Royal Society of Chemistry