The Future of the Transistor

I've been out of the semiconductor materials and devices game for a while, but I wouldn't be so sure. Just because these materials have a lot of papers about them, doesn't mean they're the future. They get a lot of papers written about them because they're relatively easy to study and because governments are funding research on 2D materials (though I can't really say why they receive so much funding. It's completely disproportional to their promise.)

Even if you could manufacture wafer scale 2D material transistors with high yield (which is a huge if), what does it buy you? Based on my, admittedly out of date, knowledge of 2D semiconductor devices, they're no panacea. Contact resistance is even more of a problem than it is for silicon at leading edge node scales. But even if it could match, or maybe even slightly beat the performance of silicon (another huge if), again, what does it buy you? One extra node, if you're lucky?

No, if my money had to be on a CMOS successor, it would be on nanoscale vacuum switches. Basically a vacuum tube scaled down to modern VLSI dimensions, at which atmospheric pressure is sufficiently low pressure to operate. Their biggest problems are 1) the lack of a complementary switch (so no CMOS equivalent, at least not without MEMS which doesn't scale), and 2) device longevity, which is likely solvable. These devices are far more manufacurable than 2D semiconductor material transistors. All of the process steps already exist, they can be stacked, unlike semiconductors, which must be single crystalline for good performance and therefore cannot be grown on insulators, device characteristics have a much higher ceiling thanks to the full vacuum barrier, and contact resistance is far less of a problem, because all of the junctions are between metals.

My second runner up would be room temperature superconductor switches, but we don't have that technology yet.

That's odd. From my perspective, an ideal transistor has zero temperature sensitivity across the linear range, zero voltage drop across the PN junctions, a beta cutoff frequency of infinity Hz, 0 ohm stray base resistance. Oh, and doesn't overheat.

I think OP meant "An ideal MOSFET". :)

You wonder about that statement. Costs will truly be out of control in future nodes. To the point where basically no one can afford the transition. Will we enter a world where higher performance is possible, but no one pursues on the account that silicon is "good enough?" This would be the equivalent of the abandonment of supersonic flight.

Alternatively, we may see a radical shift in how the semiconductor world works. Instead of everyone moving to the next node, we instead see a split market. There will be a market for those who can afford to pay millions of dollars for a very special kind of chip made with special transistors. And there will be market for normal people.