Wanted: SiC Power MOSFETs

Maybe this site will lead you somewhere to find source.

Thank you, Bill - I think it`s still not the time to get these devices. There are many activities in the backgroung at institutions like NASA but the commercial sale seems to have to wait.
Bye - Uwe

It's basically difficult to make SiC MOSFETs.

Silicon is a natural material for MOS, as it has a native oxide that can easily be grown with a very high quality.

If you try create your dielectric by oxidising SiC, the carbon oxidises to CO2 gas, which has to diffuse through the SiO2 dielectric before it can escape. CO2 is not a very small molecule, so it causes damage on the way out. So the oxide needs to be (effectively) deposited. That means the original semiconductor surface you are coating remains in place, together with any defects or impurities. And MOS is famously sensitive to surface and oxide quality.

Not easy, but it is, as others say, being worked on. Loads of differing approaches.

It's possibly even harder than the rare-earth oxides being worked on for < 40-nm silicon geometries - because here they can at least build on a stable initial oxide layer. And of course there is nothing like the level of commercial pressure for SiC (yet?)

Unless someone knows different, of course.

Hi,

why not depositing (may be 10 to 100 molecular layers) first a gradually decreasing carbon content and increasing silicon,then pure silicon, then oxidise most of the silicon?

RHABE

As I understand it, you would have to oxidise almost all the way through through the Si layer without significant oxidation of the carbon in the mixed layers. Tricky, as even in stochiometric SiC the carbon is quite readily oxidised.

(I'm not certain it would be necessary for the Si to be mono-crystalline - so it might be adequate to grow amorphous or poly-silicon on the SiC surface without buffer layers. But you still have the problem of the SiC surface oxidising - remember that many of the major uses are for relatively high-Voltage devices, so the tricks that can be used for nano-metre-effective-thickness dielectrics may not work.

NB I am at least twenty years out of date in terms of watching this technology, so the problems that exercise me could well have been solved - though apparently not yet for volume production.