The team cleverly exploited this property.įirst they laid down a layer of silicon dioxide for the base structure. The width and length of a graphene sheet are, of course, bigger than a nanotube-but the edge is a single carbon atom thick. Graphene has all kinds of interesting properties, one of which is excellent conductivity. Unroll a nanotube and you get a sheet made of carbon atoms called graphene. But instead of carbon nanotubes, which are a nanometer across, they looked to go smaller. Molybdenum disulfide’s natural resistance prevents this leakage at the tiniest scales.īuilding on this prior work, the researchers in the most recent study also chose molybdenum disulfide for their channel material and a carbon-based gate. Silicon is a better semiconductor, as electrical currents encounter more resistance in molybdenum disulfide, but when gate lengths dip below five nanometers, electrons leak across the gates in silicon transistors. In 2016, for example, researchers used carbon nanotubes-which are single-atom-thick sheets of carbon rolled into cylinders-and a 2D material called molybdenum disulfide to achieve a gate length of one nanometer. Recent advances in extreme transistor gate miniaturization rely on some fascinating materials. The gate switches this current on or off depending on the voltage applied to it. Electrical current flows from the source, through the channel, past the gate, and into the drain. Transistors have a few core components: the source, the drain, the channel, and the gate. “This could be the last node for Moore’s Law.” Etching a 2D Sandwich “In the future, it will be almost impossible for people to make a gate length smaller than 0.34 nm,” the paper’s senior author Tian-Ling Ren told IEEE Spectrum. By scaling gate lengths down to the size of single atoms, the latest work sets a new mark that’ll be hard to beat. Previous research had already pushed gate lengths to one nanometer and below. The gate, a chip component that switches transistors on and off, is a critical measure of transistor size. In a paper published in Nature this week, scientists at Tsinghua University in Shanghai wrote that they’ve built a graphene transistor gate with a length of 0.34 nanometers (nm)-or roughly the size of a single carbon atom. Electronic components that once fit in your palm have long gone atomic, vanishing from our world to take up residence in the quantum realm.īut we’re now brushing the bitter limits of this trend. ![]() It all depends on who your audience is and what type of information you are trying to communicate when you use terms like "standard cell library instance count" vs "raw gate count".There’s been no greater act of magic in technology than the sleight of hand performed by Moore’s Law. So the standard library parts may not be an accurate description of how the big or small the design is to an outsider because the design might be closer to 1.2 millin 2 input NAND gates. Then there are macros, memories and custom cells,etc. ![]() Maybe even some special cells in the library that would have complex function. ![]() So my disign might use 400k standard cell instances of all types and parts. how many 2-input, 1x drive strength NAND gates the design might be equivalent to. I tell them a very rough estimate of GATE counts, i.e. If someone OUTSIDE the company asked me how big my design is. Then I tell them the estimate of the standard cell library instances. So if someone asked me how big my design is, I'm usually talking to another engineer at my company or on my project. I find that marketing and consumers tend to put more emphasis on these numbers.Īs a designer, what I'm concerned about is how big the design is interms of slilicon aera (mm x mm) and how man standard cell parts, and which TYPE of standard cell parts my design uses. So someone might say "transistor count" instead of "gate count" when describing the design if they want a bigger number.Īs a designer, none of this should really matter to you much. Sometimes people confuse design metrics on purpose in order to achieve their goals. ![]() Like "how big is the chip?", "how fast is the chip?", "how much power does it consume?", etc. This falls under the category of what is design metrics.
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