Deep N-well Depletion Regions

[mult]

Hello there,

could anybody tell me, what happens if two depletion regions of deep N-wells reach each other?

Thanks in advance!

 

[dick_freebird]

In a FET, BJT or diode the reach-through is onset of early breakdown. But I have never noticed a more general description (though any 3-region device could be considered a transistor of some, possibly degenerate sort)..A difference might be that transistors / diodes tend to be biased with different terminal voltages while (say) two closely spaced Newell regions might have zero potential difference and then zero outcome.

 

[timof]

When two depletion regions (n-p and p-n) merge, you do not have a quasi-neutral p region (that has a high potential barrier for electrons), it becomes fully depleted. The barrier becomes dramatically lower, which may increase exponentially the leakage (current) between the n regions. This condition is often called punch-through.