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Modeling >> Semiconductor Devices >> SiGe bipolar modelling
https://designers-guide.org/forum/YaBB.pl?num=1101221105

Message started by dini on Nov 23^rd, 2004, 6:45am

Title: SiGe bipolar modelling
Post by dini on Nov 23^rd, 2004, 6:45am

Hello

I am looking for hicum based extraction tools for HBT.
It seems that Hicum is well suited for scalable extraction, which is just a dream with SGP model or even with Mextram. Am I right?

Thanks ,

Title: Re: SiGe bipolar modelling
Post by Geoffrey_Coram on Jun 6^th, 2005, 8:14am

A quick Google search came up with http://www.xmodtech.com/ for Hicum extraction.

I have heard the same story you have (hicum better for scalable extraction), but we use an enhanced Gummel-Poon model and have nice scalable models. Maybe our characterization guy is just smarter than your average Joe. :)

Title: Re: SiGe bipolar modelling
Post by rf-design on Jun 10^th, 2005, 12:33am

Could you explain what are "Gummel-thingy" models means! Is it augumented by additional components with an inline subcircuit?

Title: Re: SiGe bipolar modelling
Post by Geoffrey_Coram on Jun 23^rd, 2005, 7:39am

Hmm ... that's odd. I typed P O O N, but the software translated it to "thingy."
I'll have to check with the webmaster.

We have our own simulator, so we built the model into it -- much more flexible than subckts.

Title: Re: SiGe bipolar modelling
Post by Ken Kundert on Jun 23^rd, 2005, 9:15am

The obsenity filter was converting "Poon" to "Thingy". I have removed that particular translation.

-Ken

Title: Re: SiGe bipolar modelling
Post by extractor_man on Mar 22^nd, 2006, 1:24am

Geoffrey_Coram wrote on Jun 6^th, 2005, 8:14am:

thanks Geoffrey,
well, could you tell me more qbout you on house enhanced SGP model if it is not too confidential? For example
-Is your ft well modeled and the scalability valid ? (versus lenght, width, and configurations).
-are your parameters physical meaning?
-your max Ft? technology? (SiGe 0.35, 0.18? 0.13?)

Title: Re: SiGe bipolar modelling
Post by Geoffrey_Coram on Mar 22^nd, 2006, 9:15am

We added some features to SGP, so all the pros and cons are mirrored in terms of the core equations, scalability, physical meaning. We added things like self-heating and weak avalanche.

fT is well modeled.

We're using the model for our internal eXtra-Fast Complimentary Bipolar processes.

Title: Re: SiGe bipolar modelling
Post by loose-electron on Aug 1^st, 2006, 8:46pm

A minor comment -

Bipolar geometry scaling does not work as nicely (in theory anyhow) as does CMOS scaling. (lets ignore geometry binning for the moment shall we? :D )

Consequently a lot of the models get developed fixed geometry without size scaling. (ergo lots of unique, one model fits one transistor models)

When I was part of IBM we were using the VBIC95 model for the 5HP, 5HPE, and later SiGe processes. FWIW it seemed to give pretty good corellation to silicon.

Title: Re: SiGe bipolar modelling
Post by extractor_man on Aug 4^th, 2006, 8:38am

Well, you are talking about the "old" 0.35 um IBM SiGe process?

Today, they are using Hicum 2.1 in 0.13 SiGe process (8HP?) ! according to :
http://www.nsti.org/Nanotech2006/WCM2006/WCM2006-RMalladi1.pdf

Title: Re: SiGe bipolar modelling
Post by loose-electron on Aug 4^th, 2006, 10:13am

Thats out of UCSD as well as out of the foundry group in Vermont. Must be one of Larry Larson's students.

The 5HP, 5AM, 5HPE, and 6HP processes all used the VBIC95 models if I recall correctly. If they went on to different models after that I am not sure.

:) Good news - most model development coming out of IBM is pretty good. No complaints from me on what they do there.

>:( Bad news - There are a lot of bad models out there. I know a lot of horror stories.