Antenn effect-charge accumulation

[saha.123]

If we go with the jumper insertion(for example metal1-metal2-metal3-metal2-metal-1)for the antenna violation,then what about the total charges accumulated on the exposed conductor to the gate?whether the elongated metal connection to the gate with metal1 & jumper inserted connection to the gate both have same amount of charges??

thanks in advance
regards
saha

 

[dick_freebird]

Charge dissipates between etch steps. You are trying to keep
the charge taken by any particular step, manageable. Once you
get to the jumper-layer etch, the preceding etches' charging
has been "reset" and the jumper itself has trivial periphery, for
a win.

 

[erikl]

• During Reactive Ion Etching (RIE) of metal1 you have to consider metal1 + poly routing area for the antenna effect
  
• During metal2 etch you have to consider metal2 + metal1 + poly routing areas
  
• During metal3 etch you have to consider metal3 + metal2 + metal1 + poly routing areas

I think jumping back to lower metals may help only up to the metal2 etch (in your case). During metal3 etch it doesn't help, as the metal layers are already connected by their vias, so the trapped charges can accumulate on the total connected routing area anyway. If there's no junction connected on the way, better use a (small) reverse biased p-n-diode adjacent to the gate.