Assura DRC Error for Enclosure

[raghavathej]

I am trying to verify above DRC error (Enclosure rule).

This is what is there in the assura rule file.

L48775=geomStraddle(Nwell Nburied)
L92003=geomAndNot(L48775 Nburied)
errorLayer(L92003 "NBL.E.1: Minimum Nburied to Nwell enclosure >= 0.2 um")
L91383=drc(Nburied Nwell enc<0.2)
errorLayer(L91383 "NBL.E.1: Minimum Nburied to Nwell enclosure >= 0.2 um")

Why do we need geomStraddle & geomAndNot ?
cant we directly use enc < 0.2 i.e last two line to verify this rule ??
Please explain.

 

[erikl]

Why do we need geomStraddle & geomAndNot ?

Because some (careless, or bad) layouter (or a data transmission error) could have introduced an Nwell figure straddling the Nburied polygon (L48775),
or an Nwell polygon without any Nburied around (L92003). The enclosure rule (L91383) just monitors sufficient overlap.

 

[raghavathej]

Because some (careless, or bad) layouter (or a data transmission error) could have introduced an Nwell figure straddling the Nburied polygon (L48775),
or an Nwell polygon without any Nburied around (L92003). The enclosure rule (L91383) just monitors sufficient overlap.

Thank You,

In that case it should have been

L92003=geomAndNot(Nwell Nburied)

But, Why is it L92003=geomAndNot(L48775 Nburied) ?

Why did L48775 being used in L92003 ?

Please Explain.

 

[erikl]

In that case it should have been L92003=geomAndNot(Nwell Nburied)

This wouldn't find the straddling Nwell geometries. Nwell without Nburied [geomAndNot(Nwell Nburied)] will be found by L91383

Why is it L92003=geomAndNot(L48775 Nburied) ? Why did L48775 being used in L92003 ?

I think this works faster, as L48775 is already available.

 

[raghavathej]

L74071=geomAnd(Nburied Pimp)
L86534=geomAnd(L74071 Oxide)

L85630=geomHoles(Nwell)
L90545=geomAndNot(L85630 Nwell)

L99790=geomAnd(L90545 Nburied)
L2314=geomStraddle(L86534 L99790)
L74105=geomAndNot(L2314 L99790)
errorLayer(L74105
"NBL.SE.3: Minimum Nwell ring (on Nburied) to P+ Active spacing >= 0.09 um")
L47721=drc(L99790 L86534 enc<0.09)
errorLayer(L47721
"NBL.SE.3: Minimum Nwell ring (on Nburied) to P+ Active spacing >= 0.09 um")

Please Explain line by line(what happens in each command) how he is arriving at L47721 ?

 

[erikl]

The Assura language is quite self-explaining. If necessary, read the Assura Physical Verification Command Reference!