Finally, some modern trench.
Doesn't look like any evidence of stripes on top, wonder if that's because they really are narrower than is optically resolvable, or the top metal is so thick as to overshadow it. Which seems impressive in its own way, metal isn't usually (or doesn't usually seem) that thick! Might well be both together.
On a related note, I've realized something I think about planar types... particularly for higher voltage ratings, the channel region pinches off at a voltage that corresponds to the presumptive strip width. That is, the Coss shows a sharp drop around 5 to 30V, then a more relaxed drop rate beyond there.
I was looking at this recently,
https://www.infineon.com/dgdl/irfp4768pbf.pdf?fileId=5546d462533600a40153562c959b2021With a 2016 date, this is probably the latest greatest in the "HEXFET" lineage (alas, they don't note what generation it is). Notice the inflection point and faster drop in Coss at 4-6V. The SOA is also highly compromised at high voltages, illustrating the high power density of this design. Compare with a much older "large" transistor like,
https://alltransistors.com/adv/pdfview.php?doc=irfps43n50k.pdf&dire=_international_rectifierwhich shows the same Coss drop at 15-20V. I wonder if pitch is proportionate, and the '4768 is fully 4x finer?
I think trench don't show the same pinch-off effect, as the drift region comes right up to the end of the (vertical) channel; but I haven't looked over too many datasheets with this aspect in mind so there may be more about this. The above part is also rated quite low voltage; the drift region width is probably comparable to pitch, and at a relatively high doping level. Hmm, a shame it's not rated for avalanche, even single-pulse.
Tim