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Modeling >> Passive Devices >> Defining silicon substrate for Momentum .. An example please
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Message started by DoYouLinux on Nov 5^th, 2009, 6:22am

Title: Defining silicon substrate for Momentum .. An example please
Post by DoYouLinux on Nov 5^th, 2009, 6:22am

Hi all,

I am trying to study ADS Momentum by myself to design an inductor. At the moment, I would like to define a silicon substrate in Momentum. However, I am very confused about this step.

Could anyone show me an example showing how to define a silicon substrate in ADS Momentum please ?

Thank you very much,

DYL

Title: Re: Defining silicon substrate for Momentum .. An example please
Post by RFICDUDE on May 11^th, 2010, 7:00pm

The substrate definition has to first start with the substrate and dielectric layers defined for the specific silicon technology you are using. Usually, most of this information (dielectric constants and layer conductivity/resistivity) are documented in the proprietary information provided by the foundry.

After defining the substrate dielectric layers (usually the bulk substrate and interconnect dielectric layers) then you can start defining and mapping metal layers as "strips" between dielectric layers and you also define/map "via" layers to connect metal layers together. Again, the proprietary documents from the foundry will provide you with the metal thicknesses and conductivities. Sometimes they just provide the layer thickness and a sheet resistance, so in this case you will have to calculate the conductivity from the known thickness and sheet resistance.

Title: Re: Defining silicon substrate for Momentum .. An example please
Post by rfcooltools.com on Jun 14^th, 2010, 5:17pm

Some typical values
si conductivity 10 -100 S/m
si thickness 250uM
si Erel 11.9

if your design is below 3GHz the above conductivity will have little impact on especially if your Q is low 15 or less.

As the frequency of interest goes up will the concern of substrate conductivity come into play, but this will depend on the height of the metal above it, and the thickness, width, and conductivity of the metal.

http://rfcooltools.com