managed to develop for the first time a technique for measuring the energy and heat dissipation in transistors built from carbon nanotubes - in order to prevent such components from destroying themselves in self-heating processes, this as part of the search for technology to replace silicon
IBM scientists reveal a research breakthrough in the field of nanoelectronics. The researchers at the IBM laboratory in Yorktown, New York, succeeded for the first time in developing a technique for measuring the energy and heat dissipation in transistors built from carbon nanotubes - in order to prevent such components from destroying themselves in self-heating processes.
The researchers are looking at new ways to improve the heat management capacity and the energy dissipation in extremely tiny structures of chips that will be produced with a completely new technology. They found ways to measure the temperature at the single nanotube level, which was not possible until now. With the help of this technology, the researchers revealed how the electrical charge flowing through the component is converted into heat - and what the emission and dispersion patterns of this heat are in the structure of the component
The computers we are familiar with today, such as desktop systems or notebook computers, use silicon chips that are increasingly miniaturized, in order to allow them to operate faster and offer higher efficiency in current consumption. For this purpose, an increasing number of transistors are crammed into a single chip - and the smaller the transistor, the higher its performance. In order to create smaller transistors, chip developers are exploring the possibility of using carbon nanotubes. Such nanotubes are actually cylinders (cylinders) built with rings of six carbon atoms each, with a diameter of 1-2 nanometers: one hundred thousandths of the thickness of a single human hair.
However, before these new ideas are implemented and carbon nanotubes are integrated into chips that operate in the real world, the behavior of these atomic structures must be studied and understood: one of the serious limitations of the use of carbon concerns its vulnerability to heat, at the internal temperature levels that a computer chip may reach, and at which it is required act. A too dense concentration of carbon nanotubes may pose cooling problems that are beyond the capacity of fans known today, which compress air between the various circuits. Too high heat lowers the performance, and may eventually lead to the self-destruction of the nanotubes.
The scientists at IBM are now trying to understand how the electrons flow through the new material and structures. It is already clear that this is a completely different flow pattern than the one known in silicon. Carbon nanotubes are based on materials such as graphene (a chemical structure made of carbon, characterized by a special set of bonds emerging between the individual atoms) and present an unusual mechanism of heating and heat distortion, which may have wider implications for the world of nanotechnology in general.
The heat in carbon nanotubes is generated by the rapid vibration of the atoms through which the current passes. The faster this vibration is, the more heat these atoms create. This heat is emitted to the substrate of the chip: the material that holds the nanotubes in place and supports them. The scientists at IBM connect the understanding of the process of heating and the self-destruction of carbon nanotubes as a result of the emission of heat - and the understanding of the destruction processes created due to excessive heat in silicon chips. The problem with computers in general is to understand not only how a single component heats up - but to analyze the heating of the entire computer. If we take, for example, a laptop computer and place it on our thighs while working - we will eventually feel the heat emitted from the computer and transfer to the leg on which it is standing. As with the problem of dispersing the heat generated in the carbon nanotube - here, too, it is a matter of transferring heat from the component to the substrate and the general base of the computer.
The new materials made of carbon work differently from silicon, creating material and transferring it through completely different processes. The researchers must now understand the scientific basis that characterizes the heating processes of nanotubes, so that they can indeed be used in computing components.
The scientists at IBM tested and searched for efficient ways to transfer the heat from the nanotube to the supporting substrate, with the help of another material also based on carbon, which will be inserted between the nanotube and the substrate. The findings of this new research bring with them an important scientific innovation in itself, which is essential for building a thermal management system that will regulate the heat in future components, which will be based on carbon nanotubes.
The current research is a first and basic step in understanding the heating and cooling processes of nanotubes. In the future, many more studies will be required until it is possible to produce such nanotubes on a commercial basis, in order to integrate them into computer chips.
The results of the research are published this week in the scientific journal Nature Nanotechnology.
