Ultra thin laptops of the future could become a lot thinner, after MIT breakthrough with chip construction
Researchers at MIT (Massachusetts Institute of Technology) have developed a new new chip fabrication approach that uses different materials within a single chip layer.
The development is potentially significant, because traditional chips are made by stacking layers of different materials and etching patterns into them.
But the MIT approach, as revealed ‘Advanced Materials’ publication, utilises different materials in the same layer for the first time. By depositing different materials in the same layer, the researchers “built chips with working versions of all the circuit components necessary to produce a general-purpose computer.”
This means that as more computer components can be crammed onto a chip, it could reduce size, and possibly allow for much thinner and flexible computers in the future. Or the combination of multiple of computing devices.
This is because MIT reports that the experimental chip created by the researchers utilised layers of material that are extremely thin. Indeed, each layer is only between one and three atoms thick, so it would be possible to make thin, flexible, transparent computing devices, which could be laminated onto other materials for example.
“The methodology is universal for many kinds of structures,” said Xi Ling, a postdoc in the Research Laboratory of Electronics and one of the paper’s authors. “This offers us tremendous potential with numerous candidate materials for ultrathin circuit design.”
The researchers pointed out that this technique has possible significant implications for the development of the “ultralow-power, high-speed computing devices known as tunneling transistors and, potentially, for the integration of optical components into computer chips.”
“It’s a brand new structure, so we should expect some new physics there,” said Yuxuan Lin, a graduate student in electrical engineering and computer science and the paper’s other author.
The Techy Bit
At the moment computer chips are built from crystalline solid materials whose atoms are arranged in a regular geometrical pattern known as a crystal lattice. Until now, only materials with closely matched lattices could be deposited laterally in the same layer of a chip.
But the researchers’ experimental chip uses two materials with very different lattice sizes: molybdenum disulfide and the wonder material graphene, which is a single-atom-thick layer of carbon.
To built their new laterally integrated circuits, the researchers first deposit a layer of graphene on a silicon substrate. Then they etch it away in the regions where they wish to deposit the molybdenum disulfide.
Next, at one end of the substrate, they place a solid bar of a material known as PTAS, said MIT.
They heat the PTAS and flow a gas across it and across the substrate. The gas carries PTAS molecules with it, and they stick to the exposed silicon but not to the graphene. Wherever the PTAS molecules stick, they catalyze a reaction with another gas that causes a layer of molybdenum disulfide to form.
“This work is very exciting,” said Philip Kim, a physics professor at Harvard University. “The MIT team demonstrated that controlled stitching of two completely different, atomically thin 2D materials is possible. The electrical properties of the resulting lateral heterostructures are very impressive.”
MIT is not alone is claiming to make great strides in the development of chips of the future. IBM for example is investing heavily in chip research.
And last July Big Blue claimed a breakthrough with a new ultra-slim chip. Its research division successfully made test chips containing transistors measuring 7nm across, which it said was the thinnest ever made using this technology.
IBM said that could lead to slimmer, more powerful devices, as the new chips feature up to four times the capacity of today’s most powerful chips, meaning it could soon be possible to build microprocessors with more than 20 billion transistors.
MIT researchers have meanwhile previously developed a way for sensors to essentially power themselves, as they are designed to extract energy from the environment in order to charge.
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