Modified the magic tech file for gf180mcu to use the GDS layer 23:5 as an isolated substrate marker (isosub). This layer is not documented (that I could find), but that is clearly what it is being used for.
diff --git a/gf180mcu/magic/gf180mcu.tech b/gf180mcu/magic/gf180mcu.tech index aff87bb..0b34391 100644 --- a/gf180mcu/magic/gf180mcu.tech +++ b/gf180mcu/magic/gf180mcu.tech
@@ -675,6 +675,12 @@ calma 12 0 #----------------------------------------------------- +# SUBCUT +#----------------------------------------------------- + layer SUBCUT isosub + calma 23 5 + +#----------------------------------------------------- # NWELL #----------------------------------------------------- layer NWELL allnwell @@ -1595,6 +1601,9 @@ layer dnwell DNWELL labels DNWELL + layer isosub SUBCUT + labels SUBCUT + templayer ndiffarea DIFF and-not POLY and-not NWELL @@ -2622,6 +2631,7 @@ calma NWELLTXT 21 10 calma PWELL 204 0 calma PWELLTXT 204 10 + calma SUBCUT 23 5 calma DIFF 22 0 calma DIFFFILL 22 4 calma POLY 30 0 @@ -3582,7 +3592,7 @@ # See document 180MCU_YI-141-EP059-01_10.pdf resist (nwell,dnwell)/well 1000000 - resist (pwell)/well 3250000 + resist (pwell,isosub)/well 3250000 resist (*ndiff,nsd)/active 6300 resist (*pdiff,*psd)/active 7000 @@ -3686,7 +3696,7 @@ # High-end corner resistances (milliohms per square) resist (nwell,dnwell)/well 1200000 - resist (pwell)/well 3250000 + resist (pwell,isosub)/well 3250000 resist (*ndiff,nsd)/active 15000 resist (*pdiff,*psd)/active 15000 @@ -3790,7 +3800,7 @@ # Low-end corner resistances (milliohms per square) resist (nwell,dnwell)/well 800000 - resist (pwell)/well 3250000 + resist (pwell,isosub)/well 3250000 resist (*ndiff,nsd)/active 1000 resist (*pdiff,*psd)/active 1000