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https://designers-guide.org/forum/YaBB.pl Modeling >> Semiconductor Devices >> Jmelt Jmax for BSIM in spectre https://designers-guide.org/forum/YaBB.pl?num=1169079234 Message started by jbdavid on Jan 17th, 2007, 4:13pm |
Title: Jmelt Jmax for BSIM in spectre Post by jbdavid on Jan 17th, 2007, 4:13pm I was hoping to use these, to get current density warnings, but spectre manuals tell me these are Amps/um^2.. I'm assuming 1 dimension is transistor W, but the other cannot be Length.. , has to be depth.. of WHAT? What I want to specify is similar to TSMC manual, Jeff = Id/w BSIM spec does NOT mention these parameters at all.. and Spectre manual doesn't explain how to get Jds from Ids! Guess I have to write assertions for this instead.. If someone knows what thickness would be used, please post it here.. |
Title: Re: Jmelt Jmax for BSIM in spectre Post by marekm on Jan 17th, 2007, 4:35pm I don't know about Spectre, but usually those explosion limits apply to p-n junctions so I would suspect that they refer to the s/d areas for the junction diodes. |
Title: Re: Jmelt Jmax for BSIM in spectre Post by jbdavid on Jan 17th, 2007, 5:56pm Id wouldn't flow thru the junction diodes though.. and these aren't described in the Junction Diode parameter section. But I hadn't really considered that possibility.. jbd |
Title: Re: Jmelt Jmax for BSIM in spectre Post by Ken Kundert on Jan 17th, 2007, 7:00pm I think marekm is right. I think those are parameters for the substrate junctions. -Ken |
Title: Re: Jmelt Jmax for BSIM in spectre Post by Geoffrey_Coram on Jan 18th, 2007, 4:14am imelt, jmelt are in the diode section imax, jmax are in a section with alarm, vbox which aren't diode parameters. Jonathan - did you try it? Can you get a jmax warning with drain current? It might be that the units listed are wrong (or A/m^2 is used for the diodes, and A/m is used for the drain current). -Geoffrey |
Title: Re: Jmelt Jmax for BSIM in spectre Post by Ken Kundert on Jan 18th, 2007, 8:25am Both the max and melt parameters apply to the junction diodes. The max parameters specify where the IV curves deviate from the expected exponential so as to improve convergence, and the melt parameters specify when a warning should be given. This is all explained in "spectre -h bsim3v3" under a special section titled "Imax and Imelt". -Ken |
Title: Re: Jmelt Jmax for BSIM in spectre Post by jbdavid on Jan 18th, 2007, 3:46pm And Geoff verified that thru simulation.. - so for me thats a dead end, since what I need is Ids/Wmetal < Jmax Metal.. Appreciate the quick help!! jbd |
Title: Re: Jmelt Jmax for BSIM in spectre Post by Ken Kundert on Jan 19th, 2007, 12:29am You might look into the new assertion features in Spectre. -Ken |
Title: Re: Jmelt Jmax for BSIM in spectre Post by jbdavid on Jan 22nd, 2007, 8:50pm Reading about Jmax made me hopeful that I could avoid that.. but Geoff dashed those hopes.. guess its about time to play with those .. Jonathan |
Title: Re: Jmelt Jmax for BSIM in spectre Post by Andrew Beckett on Jan 23rd, 2007, 2:04am Hi Jonathan, assert is very easy to use. spectre -h assert gives you a very good starting point (as you'd expect). So there's no need to be fearful of using asserts! Regards, Andrew. |
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