dopant

Even so, the security is nowhere close to the absurd level needed when faced with an attacker capable of dopant-level hardware backdoors.

Obviously more bits means closer thresholds, making the gate more susceptible to electrical noise when reading and writing (and process variation in the dopant loading).

Transistors go underneath capacitors, which means they have to survive the subsequent fabrication of the capacitors without thermal processing disrupting their carefully engineered dopant profiles.

Or, just use gallium instead of boron as the dopant so it doesn't suffer from light-induced degradation.

From the paper: > our dopant Trojans are immune to optical inspection, one of the most important Trojan detection mechanism.

And over time, electromigration (where dopant atoms get kicked out of position by interaction with electron momentum) will slowly degrade their performance.

I don't believe gallium is significantly toxic, and certainly not at the amounts used as a dopant.

Now wonder if complimentary P-channel is also possible by using regular boron dopant?

And, maybe in the future, gallium as a dopant in silicon cells, since it doesn't experience nearly as much light induced degradation as boron does.

One makes the entire dye with a kind of dopant, creates a oxide layer above it, and remove the oxide where it should be doped again.

Boron is usually the P type dopant of choice.

Actually, gallium has replaced boron as a dopant for Si PV cells, since it avoids an annoying kind of light-induced efficiency degradation that boron is subject to.

Seems they used "regular" planar lithography process with same old dopant (phosphorus).

But if transistors are set to be always on state by the ion implantations, it has a drastic effect" I think you could detect dopant tampering (and these traps) with scanning capacitance microscopy, but I don't have any actual experience with that.

Dopant migration or something, I'm not an expert.