but, i can tell some tips regarding metal routing..
You can route metals over MOS but you should not touch or short the MOS terminals with the SAME mETAL.. fOR EXAMPLE, IF you use metal1 means u cant draw over mos becuase the drain and source of the mos covered with metal1 so u can use metal 2 and others,, no problem to route over MOS..
but, i can tell some tips regarding metal routing..
You can route metals over MOS but you should not touch or short the MOS terminals with the SAME mETAL.. fOR EXAMPLE, IF you use metal1 means u cant draw over mos becuase the drain and source of the mos covered with metal1 so u can use metal 2 and others,, no problem to route over MOS..
Routing with metal 1 or 2 will affect dopings in gate or drain/source and obviously add parasitic capacitances.
From Metal3 and above, it affect only parasitic capacitance. So, we avoid such routing.
In some case, those effects are not critical if your amplifier is not critical ...
yeah u can do it but make sure that u don't route metal1.
From metal2 and above will be fine and also while routing keep in mind that u should'nt use vias (any vias) above the active(PO+OD) area. If u place a via above active it effects the Vt of the mos, which is critical.