For the first time scanning and tunneling microscopy (STM) has been used by a research collaboration between Nara Institute of Science and Technology and Osaka University for creating images of atomically flat side surfaces of 3D silicon crystals. This is anticipated to help semiconductor manufacturers in their efforts for innovation, as they strive to achieve faster, smaller, and energy efficient computer chips for smartphones and computers.
Smartphones and computers are loaded with tiny transistors in millions and the more the transistors that can fit on a single computer chip, the more the speed of these devices. As per Moore’s Law, every 2 years, the number of transistors per chip will increase by double! In order to keep up the pace of innovation manufacturers of computer and smartphones are constantly on the hunt for newer methods to reduce the size of transistor further.
At present microprocessors are made by adding patterns to silicon wafers which are flat. Fabricating 3D structures is a novel way of cramming more transistors in the same space. Fin-like silicon structures are thus being used as they can extend into the air, off the surface of the chip, thus requiring lesser space. These transistors are aptly called fin-type field effect transistors. (FETs). In order to implement this method, a silicon crystal with flat tip and side surfaces is required, rather than just the top surface which the current devices are already using. Thus, there will be need to have knowledge about atomic structures of side surfaces so as to design next generation chips.
Researchers at Nara Institute of Science and Technology and Osaka University have used STM to image the side surface of a silicon crystal for the first time, which is a powerful technique for allowing locations of individual silicon atoms to be seen. Electros can jump across gap and create electric current when a sharp tip very close to the sample is passed. Microscope was used to monitor this current and helped in determining the location of the atoms in the sample.