[SOLVED] Different Resistor Process Variation Direction

[pooh_bear]

Hi,

Does anyone know if the process variations change in the same direction for all resistors or some resistors e.g P+ poly resistor with and without Salicide and an N+ poly resistor with and without Salicide or diffusion resistors?

I see that for process variations that all resistors lower, but does that reflect whether different types of resistors vary the same way?

If the resistors like poly or diffusion do vary together over process what elements would those be? If only some of the elements or process changes in one direction over process how would I capture this?

Anyway, thanks. Any help or reference is appreciated.

 

[Dominik Przyborowski]

Answer is simple. No, they don't.

 

[dick_freebird]

Only poly grain characteristics and silicide sheet
resistance will be common. N+ and P+ are independent,
poly depletion is going to be opposite directions (or
one species changes and one does not) for non-
silicided poly (depletion is there for silicided, but will
not affect sheets meaningfully; more of a FET issue).
It's possible that late-process drives can shift net
doping together if the process is marginal in respect
to "activation of dopant".

I'd call it random enough, correlation-wise.

 

[pooh_bear]

Thanks a lot Dominik and Freebird!