6 ms·
So now a transistor is only like ~35 atoms across!
by internalfx 9y ago
So now a transistor is only like ~35 atoms across!
- JPLeRouzic 9y agoYes that is amazing, most biological components are bigger: https://en.wikibooks.org/wiki/Cell_Biology/Introduction/Cell_size https://en.wikibooks.org/wiki/Cell_Biology/Introduction/Cell...
- Eerie 9y agoMost biological components function in 3D space, though, not on a surface.
- sbierwagen 9y agohttps://en.wikipedia.org/wiki/Multigate_device#Tri-gate_.283D.29_transistor https://en.wikipedia.org/wiki/Multigate_device#Tri-gate_.283... But you're right, actual stacked chips ("3D" ICs) aren't used much, largely for thermal management reasons.
- JPLeRouzic 9y agoI understand and agree, but most biological components at a sub-cell scale are membranes and pores in membranes, or even linear or circular structures like RNA/DNA.
- njarboe 9y agoIANAB but wouldn't most biological components in a cell be proteins (DNA codes for tens of thousands of proteins)?
- JPLeRouzic 9y agoSorry for the delay to answer. Proteins are indeed incredible little machines and for someone with a computer background, they are the most interesting entities in the biological zoo. And proteins may be very large, some are hundreds of nm. But by seing proteins as components, one misses the transport and signaling aspects which are important inside and outside the cell. It is a problem of scale, if we focus at some scale level, we miss what is going on at a smaller as well at a larger level. I think there is no easy solution to that problem.
- nitwit005 9y agoGood to see I wasn't the only one to look at the table of atomic radius to check this.
- thechao 9y agoNo. The feature size is 7nm. That's like saying the tightest radius in your CNC mill's tooling is 3mm. The stuff you make is far larger. Just look at the SRAM area: it's .0269 square microns. And SRAMs are tiny compared to "gate" RAMs, like you'd see in a book.
- joezydeco 9y agoThe first line in that slide still blows me away. 17 million gates per square millimeter.
- thechao 9y agoYeah. I'm gonna attempt a Fermi analysis to try give an idea of how much room is still "down there". 1 sq um is 100,000,000 sq angstroms. The unit cell of crystalline SI is probably around 50 sq A. That gives about 2,000,000 unit cells per sq micron. My guess would be about 5,000,000 "surface" atoms. The SRAM is .025 of that---perhaps 120000 atoms. SRAMs are cubes, so about 40,000,000 atoms cubically. Assume an SRAM is about the size of 8 transistors (that's a big SRAM): that's about 5,000,000 atoms per transistor. I'm going to fudge it down to 500,000 atoms, to be conservative. The smallest logic I've heard of is a transistor using 7 atoms in toto. That is a factor of 70,000x, or about 16 generations. Now, how we'll get there, I don't know. Also, I think the generation gap will probably widen to 5, or more, years. So... 75 to 100 years of "room"?
- xenadu02 9y agoMy understanding is that the active gate region is far smaller already so there is less room to scale than you might think.
- thechao 9y agoThe active region is smaller, but this is an argument about total bulk. IBM has shown functioning transistors with only a handful of atoms, already.