Hi, has anyone encountered the m2.5 drc error from Klayout (pls see the attached image)? In the layout, it clearly shows that m2 enclosure of via of 2 opposite edges is 0.085um but the tool still reports it’s an error?

@Nguyen Dao From

<https://github.com/laurentc2/SKY130_for_KLayout/blob/main/drc/drc_sky130.lydrc>

these appear to be the relevant rules.

via_edges_with_less_enclosure_m2 = m2.enclosing(via, 0.085, projection).second_edges  opposite7 = (via.edges - via_edges_with_less_enclosure_m2).width(0.14 + 1.dbu, projection).polygons  
via.not_interacting(opposite7).output("m2.5", "m2.5 : min. m2 enclosure of via of 2 opposite edges : 0.085um")

I found a discussion on the rule development at

<https://www.klayout.de/forum/discussion/1204/contact-via-drc-min-enclosure-on-2-opposite-sides>

Is the via size 0.14umx0.14um? (The m1 via rules have a similar check, but use 0.18um as width size.) Looks like the via size should be 0.15um. Maybe change

width(0.14

to

width(0.15

and see what happens.

@Mitch Bailey Thanks. Yes changing via size to 0.15um fix the m2.5 error but there are still issues with m3.5 and m4.5. Seems there was a mistake in the original

sky130.lydrc

from Klayout that uses metal width instead of via width in opposite7 expression. The

sky130.lydrc

from open_pdks repo helps fix all those issues.