Transistors are the fundamental components of processors, memories and other pieces of hardware, therefore, it is not uncommon for companies to seek innovations to produce increasingly advanced and efficient parts. One promising technology analyzed by scientists is the chip production using single-atom-thick “2D sheets”.
Some materials, such as graphene, have a two-dimensional molecular structure that would allow the creation of a kind of “leaf” to produce tiny transistors, such that, in theory, they can increase the performance and improve the efficiency of electrical conduction of hardware parts for cell phones, tablets and more.
Researchers have previously demonstrated that the production of transistors using two-dimensional materials is possible, but to accomplish the feat, several “manual” adjustments in the small hardware circuits were necessary, therefore, the challenge was to apply this technology in industry for mass production.
With that, the new study published this Wednesday (22) by the scientific journal Nature Nanotechnology details that it is possible to take advantage of existing technologies in the foundry of semiconductors, such that they allow dealing with incredibly thin materials for the production of processors on a large scale.
The “wiring”—that is, the tiny interconnections that link the transistors together—necessary for the electronics of the new technology used conventional manufacturing methods. In the demonstration, a nanosheet is positioned in layers on a metal surface, and then processing is done so that transistors are formed.
The scientists involved in the experiment note that this may still not be an ideal technique, since the deposit of metallic components can damage the sheet and present a risk of diffusion of atoms, causing a short circuit in the system.
To get around this issue, the team devised a way to form the individual connecting parts separately, and then, under less complex conditions, joined the parts to the 2D sheet. After that, the platform was installed in a standardized way on a solid substrate and coated with aluminum oxide.
The circuits, after being coated with aluminum oxide, were positioned on a silicon dioxide surface using a molybdenum disulfide nanosheet through chemical vapor deposition, resulting in a thin layer of semiconductor material. The whole process was carried out in stages rather than following a continuous line.
Another difficulty faced in production is aligning the interconnections with the “gates” of the transistors — mechanisms that allow switching their state between 0 or 1 (binary codes). To limit possible distortions of the system, the researchers connected the polymer of the spinning to a sheet of quartz before recording them in a wafer.
By putting all the parts in their proper place, scientists can remove any excess material easily using plasma etching — another technology widely used in semiconductor production.
While manufacturing has proven to be much more complex with 2D sheets, the researchers’ experiments have shown that the technology can make the devices we use in our everyday lives perform much more consistently and leak much less energy.
Specialists managed to produce functional circuits in the entire area of a wafer of 2 inches. While the new method is still just a demo, expectations are high.
It is still too early to say that molybdenum disulfide will be a substitute for silicon among semiconductor materials in the near future, but the global hardware crisis has shown that it is essential to have different types of raw materials available to the industry.
