My semiconductor textbook says hot carrier injection is done by applying a lot of volts (and necessarily, amps) to a FET, and electrons magically get stuck in the gate oxide. And of course, since this changes the threshold voltage permanently, it's hysteretic, so they can put them in big assed arrays with addressing and call them EPROMs. Or with another effect and another connection, EEPROMs, or in sectors, Flash.
Now that's all well and good, but is it possible to observe this in discrete FETs? Can you take a 2N7000, diode-strapped, spark a cap into it and measure a change in Vg(th)? How about IRFZ46N? What current density / terminal voltage is required to see a change? Can it even be done without burning the entire die in the process? (i.e., do EPROMs get away with it because they're burning a teensy fraction of silicon at any given time?)