Re: SCMOS rules, MOSFET width

Steven Rubin <[email protected]> Sun, 02 Nov 2008 19:53:00 -0800
Newsgroups gmane.comp.cad.electric.bugs
Message-ID <[email protected]>
At 06:50 AM 11/2/2008, you wrote:
>Dear Electric buglist,
>
>I'm having a problem with MOSFETs when using the "Analog" technology 
>option (actually it seems to be the choice of SCMOS rules rather 
>than Submicron rules in the ProjectSettings->Technology 
>menu).  Electric thinks the width of some transistors is 2 lambda 
>bigger than it really is.
>
>If I instantiate the P-Transistor-Scalable or N-Transistor-Scalable 
>I get a MOSFET with a width of 3 lambda and the active region under 
>the poly is correctly drawn at 3 lambda.  However, if I use the 
>plain P-Transistor and N-Transistor components and check the 
>properties of the transistors the width will be reported as 5 
>lambda, even though the transistors are drawn with an actual width 
>of 3 lambda.  The offending transistors are also drawn with a 3 
>lambda extension of the gate rather than 2 lambda.
>
>Moving the cursor over these transistors shows that Electric thinks 
>the pin in the channel is extended 1 lambda beyond the active at 
>each end, only for the plain transistors.
>
>Deselecting the "ProjectSettings->Technology->Analog" option and 
>changing from "SCMOS rules" to "Submicron rules" appears to fix the problem.
>
>I'm using Electric 8.07 on Red Hat Enterprise 4 linux with java 
>version 1.6.0_07. Am I doing something wrong here, or overlooking something?

You have found a bug in Electric that was fixed in September.  If 
this particular transistor configuration is necessary for your work, 
contact me and I will discuss ways to fix it.  Otherwise, our next 
release, due out before the end of the year, will correct this problem.

    -Steven Rubin