AnsweredAssumed Answered

RC extraction problem

Question asked by andrewng on Sep 2, 2009
Latest reply on Sep 8, 2009 by samantha_lizak

Dear all,

 

Is there any one experienced the same case with me?

 

Case:

I have a close loop bias transistor which source and body is connected to same power (pls see the attachment). When I extract R of this connection, we found that the resistance is much smaller than by hand calculation (such as extraction result is 29ohms while hand calculation is 59ohm; please note that I haven’t calculate the bias contact). We guess that the small resistance is caused by the diffusion contact which reduces the resistance a lot.

 

I tried to prove my guessing by setting the sheet resistance of PSD / NSD to 0 ohm/sq.  However the results showed no difference.  Could anyone give comment on it? Below is my modification in the tech file.  Is there any problem in the modification?  Do I miss something?

 

// =================================================

// ===  Resistance Sheet  [Prop_Cnst, Max_Dist]  ===

// =================================================

 

RESISTANCE SHEET NSD           [0   0 2.905E-3 -3.686E-7]  MASK

RESISTANCE SHEET PSD           [0     0 2.949E-3 -4.049E-7]  MASK

 

// ==============================================

// ===  Resistance Connections  [Area, Edge]  ===

// ==============================================

 

RESISTANCE CONNECTION METAL1 NSD             [0 0] MASK   // Contact

RESISTANCE CONNECTION METAL1 PSD             [0 0] MASK   // Contact

 

Best Regards,

Andrew

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