Questions on metal mask change?

[design_engineer]

asic respin mask

Hello,

I am not familiar with metal mask changes and the costs/difficulty associated with them.

If I want to make a functional change to my asic by disconnecting and reconnecting a few wires, can this be done using a metal mask change? Even if the wires are on multiple metal layers? I do not need to change any cells or cell placement.

Wafers have already been built for the asic so I am stuck with a respin. For a 4-layer metal process, how many masks will be needed for the metal mask change? I dont know for sure if the NRE covers respins but in general, does it? Or do I have to pay extra for the respin?

Thanks for clearing my confusion.

 

[gliss]

Typically NRE costs to not cover respins.
And the mask shop would charge you extra if any changes have to be made to a mask you already handed off.