Graphene transistors are ready to take the flag from the “weakening hands” of silicon

On the topic of what technology can eventually replace semiconductors as a new element base and snatch the banner of primacy from the “weakening hands”, many copies have already been broken. Perhaps the most interesting today are carbon nanotubes – publications about them appear in periodicals with an ever increasing frequency. However, there are also alternatives, also carbon, but having a structure different from nanotubes – so say Professor Andre Geim and Konstantin Novoselov from the University of Manchester (more precisely, from The School of Physics and Astronomy at The University of Manchester) in the March issue journal Nature Materials. In their article, scientists describe a transistor, the thickness of which is one atom, and the width is 50.

We can say that the transistor consists of graphene – a two-dimensional (flat) allotrope of carbon (in the figure – a fragment of the “crystal lattice” of graphene, which is an infinite plane). The fact that a transistor can be created on the basis of graphene became known almost immediately after the discovery of this allotrope (generally speaking, field-effect transistors can be created from a very large number of materials, not necessarily semiconductors), however, the first devices based on it had a very high leakage current. and this parameter is critically important for an industry striving to increase not only speed and capacity, but also to reduce energy consumption.

Game and his comrades proposed a simple and elegant way to solve this problem, simultaneously demonstrating that graphene remains stable and retains the ability to conduct electricity, even being in the form of nanoparticles several nanometers in size – more precisely, in the form of strips 50 atoms wide (the thickness, recall, is one atom, that is, of the order of an angstrom or an order of magnitude less than a nanometer). But the properties of silicon, and many other elements and compounds, often change when changing microscopic scales to nanoscopic. Professor Game suggests that it is likely that the bandwidth of graphene of 50 atoms is not the limit and they plan to work on creating devices of even smaller size, up to a few atoms.

According to scientists, their development will extend the life of Moore’s law even after semiconductor technologies have sunk into oblivion – that is, even after more than half a century since the formulation of the rule of thumb stating that the density of integrated circuits doubles every 18-24 months, it will be still relevant.

British scientists see the future of the element base as follows: the sources and drains of transistors are cut on a graphene sheet, the gate of which is played by “quantum dots” – “translucent” (meaning – there is a possibility of tunneling – approx. perev.) potential barriers to control the movement of electrons, as well as conductors and internal connections. Thus, in the future, for the production of integrated circuits, it will be possible to completely abandon silicon or germanium – everything will be made of graphene. The main problem, as Leonid Ponomarenko, who participates in the research project (also an employee of the University of Manchester), rightly points out, is that so far there is no technology capable of “cutting” elements from graphene with an accuracy of nanometers. Alas, the head of the research group, Professor Geim, is very restrained optimism and does not expect commercial prototypes to appear before 2025.

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