[Magic-dev] Query about 'units microns' statement in tech file extraction

[R. Timothy Edwards]

Dear Graham,

>    But I find that the result is 1000X too small. It looks like "Cap is half
> the capacitance in attofarads per micron when the edges are 1 lambda apart",

Since it may be another day or two before I can get the corrected
distribution for version 7.5 posted, this is the fix for the above
problem:

1) Edit extract/ExtTech.c
2) Line 2494, change "scalefac" to "sqfac"
3) Line 2552, change "scalen" to "sqn"
4) Line 2553, change "scaled" to "sqd"

A little investigation into the code showed that although sidewall
capacitance is a linear per-unit-distance capacitance, it is implemented
as an area capacitance, under the assumption of a unit width.  However,
that implementation requires that the value be scaled as an area
capacitance, which is what the changes above do.

						---Tim

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