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Silicon Will Get CPUs To .07 Micron
ruiner writes: "This post at EE Times discusses that it now appears that silicon dioxide can be used as an insulator down to a process of .07 micron for processors. This will buy processor manufacturers a few more years to develop solutions for smaller processes. "
Faster chips are great but x86 is getting tired and the I/O on a PC is really limiting the usefullness of the chips we're capable of making now. We need a platform capable of useing what we have now.
When someone yells "Stop" or goes limp, or taps out, the fight is over.
Electrical signals travel at the speed of light. Therefore, the smaller you can make a circuit, the faster a signal will get from one end of it to the other. And of course you can pack more of them into a given area, leading to smaller die size, which equates to more units per wafer, higher yields, and lower prices.
At this point we're getting to the limits of what can be done on a silicon substrate. The problem here is that with circuits smaller than 0.07 micron, you are in danger of splitting silicon atoms if you pump any energy at all through the circuit. Yes, you read that right -- splitting silicon atoms, resulting (theoretically) in a release of energy equivalent to the Hiroshima bomb. This, as you may have guessed by now, is the real reason the US government considers high-powered CPUs to be "munitions". Just imagine what could happen if a bunch of Islamic terrorists got hold of a few thousand such CPUs and set themselves up as a mail-order PC company.
This is not, by the way, a problem unique to ICs. The real reason for the classification of data compression products as "munitions" is related to this too. You see, if data is compressed too much, the atoms comprising the individual bits can actually begin to participate in atomic fusion, leading (for a 32 kb block of data) to a release of energy equivalent to the original H-bombs of the 1950s. There are some papers here to document all this.
Just goes to show... the government doesn't always tell you the real reasons for the decisions they make, but that doesn't mean those reasons aren't justified.
This is stretching the limits of physics. A 70 nm layer is only about 200-300 Si=O bonds thick. We're almost in the area where quantum effects become an overriding concern. I can't be bothered to work out the probability of an electron with a given voltage tunnelling through a layer this thin, but I suspect that we are in the area where voltage regulation and temperature control become *very* important. Put another way, these babies won't be candidates for aggressive overclocking.
What this really means is that we *may* have a little longer to go before we have to start using 'exotic' oxides. This is good news. One of the great things about SiO2 is that the manufacturing properties are well understood (although, at this size, lithography is going to be, er, interesting.
And they say there's a chance that they can take it even further. Gordon Moore will be pleased. His law looks good for the forseeable future.
That sounds great from a science point of view, but just not realistic from a business point of view. Let's say that a big chip company puts no money in .07 micron technology and dumps every last R&D dollar into truly next generation CPUs. What if the R&D doesn't produce a working chip until 2007? Do you think a spokesperson for AMD could take a podium in 2004 and say, "In response to Intel's announcement of 6.4 GHz CPUs, we would like to ask everyone to hold off for three years when we will deliver our 150 GHz chips...maybe." They might as well fire everyone and lock the doors. The trick for those companies is to split the funding between evolutionary and revolutionary R&D so that they can keep products coming down the pipeline right up until that huge leap can be made. I certainly don't envy the people drawing up that budget. If you want to give it a shot, try to predict the weather for June first, of next year, and "hot" won't cut it.
-B
Silicon technology is still a bulk technology. The most likely candidates for a further circuit miniaturization are what is called "molecular electronics." These involve using organic molecules with dimensions of several dozen angstroms for swithces and interconnects. People are already working very hard on metal contacts to organic molcular componet. There was a special issue of the Proceedings of the IEEE on Quantum and Nanoscale Devices and an article titled "Molecular Electronics" by Prof. Reed of Yale EE dept surveyed the field.
The Most striking figures in that article were (i) a very tiny organic molecular diode which operated at room temperature with voltages around +/- 0.5 volt, and (ii) a resonant tunneling device at room temp. with similar voltages. These are highly practical voltages and temperatures! The biggest obstacle is to integrate these devices.
The variety of possibilities offered by organic molecules in conjunction with metals and other solid materials is simply staggering. What is going to open the floodgates is development of techniques to integrate these tiny devices with tiny interconnects in an inert matrix.
Zyvex and the Foresight Institute website are the best resources for information on this subject. Particularly, the writings of Eric Drexler and Ralph Merkle.