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From: cfk (cfk AT pacbell DOT net) Date: Fri Apr 18 2003 - 15:40:44 EDT
I guess my naivete is showing a bit. Today, I am trying to understand geometry, techfiles and transistors a bit more. So, I took current.tar.gz from MOSIS and got the SCN6M_SUBM.10.tech27 for the TSMC18 process (which I believe to be 0.18um) into my /home/cad/lib/magic/sys directory. Now, I invoke "magic -w -TSCN6M_SUBM.10". I draw a pfet whose pdiff is 9 grid squares wide by 6 grid squares between the metal1 contacts of the drain and source. In the middle, I paint a 2 grid square wide poly (overhanging the pdiff by 2 grid squares). When I extract this transistor, the .spice file from magic's extractor says the transistor is 2.2u wide by 1.8u long. I also see in the SCN6M_SUBM.10.tech27 file that statements: style lambda=0.10(p) scalefactor 10 5 So, I am thinking that each grid square is .05u (0.10 * 5 / 10), which would make a pfet 9 squares wide as .45u (.05 * 9 = .45), but the .spice file says the transistor is 2.2u wide which is almost, but not exactly, 5 times bigger. Similarly, the poly is 2 grid squares long over the pdiff (in the direction of current flow), so I would think that it is 0.10u long, yet extract says it is 1.8u long. OK, maybe this really means a grid square is one half of the smallest TSMC dimension, which for the TSMC18 process I think is 0.18u. So, a pfet 9 * 0.09 wide is 0.45u and 2 * 0.09 long is 0.18u, and that seems to fit with my limited understanding of magic, tech files and the like, yet the extracted spice file says the transistor is 2.2u wide and 1.8u long. Obviously, I dont get lambda, scalefactors & tech files yet and would appreciate someone helping me understand a bit more. Charles
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