Re: SCMOS rules, MOSFET width

[Steven Rubin]

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