Future Phones May Use Vacuum Tube Chips As Silicon Hits Moore's Law Extremes (inverse.com)

An anonymous reader writes: A team of researchers want to replace transistors with vacuum tubes. Vacuum tubes are nothing new, however the ones in development at Caltech's Nanofabrication Group are a million times smaller than the ones in use 100 years ago. "Computer technologies seem to work in cycles," Alan Huang, a former electrical engineer for Bell Laboratories, told the New York Times. "Some of the same algorithms that were developed for the last generation can sometimes be used for the next generation." Dr. Axel Scherer, head of the Nanofabrication Group, said to the New York Times on Sunday, "Ten years ago, silicon transistors could meet all our demands. In the next decade, that will no longer be true." He argues silicon transistors can only take us so far. Vacuum tubes, for comparison, use tiny metal tubes that can control the flow of electricity. They're especially intriguing to researchers as they can provide a better solution to silicon transistors as they can consume less power and take-up a much smaller footprint. The report mentions they have the potential to bring an end to Moore's Law, even if silicon transistors show no signs of disappearing. For example, Lockheed Martin published new cooling methods in March that could help cool chips with tiny drops of water. With that said, Boeing has invested in researching vacuum tube chips. They may appear in the aviation industry before 2020, but it's unlikely we'll see Caltech's research appear in smartphones anytime soon.

Comments

Call me a geek

[Tx]

Call me a geek if you like, but I really enjoy watching this video of a guy hand-making triode valves (AKA vacuum tubes), it's somehow very therapeutic. Yep, only vaguely on topic, but what the hell, we're talking about vacuum tubes.

How to design complementary logic

[Anonymous Coward]

Call me dumb if you want, but I design ASICs for a living. How am I supposed to design a chip with these devices. When I design in CMOS silicon, I have the choice of four different polysilicon well types (P, P+, N and N+). Do these devices require several voltage rails to provide bias, in the way that the dopant provides intrinsic bias in a FET?

I'm not old enough to have designed valve circuits, but from what I vaguely recall, you only get emission from cathodes, so with no hole mobility I don't understand quite how these things are supposed to provide complementary logic.

Re:How to design complementary logic

[serviscope_minor]

You have to get the cathode hot enough for the electrons to want to leave and head for the plate and it takes fairly high voltages to make everything work, both of these are not good things for existing solid state devices where you want to keep the voltages and temperatures low. Doesn't seem like a good mix to me.

That's the interesting thing: you don't. Another fun fact: once you get small enough atmospheric pressure air is essentially a quite good vacuum. The other thing is that field gradient alone can get electrons to leave without heating if it's high enough. For a high gradient you need either high voltages or high curvature. With nanoscale fabrication techniques, you can make quite extreme curvatures. Since the voltages are low, even a quite good vacuum is good enough because the electrons flying through it lack the energy to ionize air molecules.

Look up "vacuum channel transistors".

The best thing is, you can make them on a standard CMOS process.