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Comment by BostonEnginerd | Hacker News Reader

SiC and GaN are being used for a fair number of parts these days for RF applications. It seems that the novel part of this paper is that the device worked up to 500C. The device worked for 3 hours with some degradation, likely due to Al electromigration from the metallization.

The acutal paper is here: https://ieeexplore.ieee.org/document/8345290/

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I was going to say my employer made this stuff, but they are getting out of the business. Must not be profitable enough.

https://aerospace.honeywell.com/en/products/navigation-and-s...

SOI is an excellent RF process, and is what would be needed to get the rest of the radio on there.

I wonder if simply cooling isn't an option in those applications? I guess that'd depend on the chips power output. Otherwise you could just surround it in a really good insulator and pump residual heat out somehow (maybe can peltiers withstand such high temps using multiple stages?)

Cooling only works if you have somewhere to put the extra energy. Peltiers are inefficient to run and generate a ton extra heat. It's best to build something that can run with as little support needed.

Indeed, cooling would be quite bulky and require lots of extra energy. But for an environment like Venus cited (instead of small sensors), I think it should be a good option. The Carnot efficiency to cool from a Venutian environment (462C) down to 50C (reasonable chip temp) is a surprisingly good ~60%. In practice you might get 15% (? plus insulation leaking), that should still allow cooling a chip of less than ~1 watt of tdp without too much hassle inside a robot.

I thought >300C power MOSFETs in SiC were already commercially available? But I might be confused.

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