Is there anybody know how the simulator gives capacitor like Cgs?

[Alex Liao]

Hi,

I want to know how the spectre gives Cgs,Cds and Cgd.
Every time I do a DC print I could see a lot of parameters.
1. For the listed three, I am wondering how the Spectre gives them. Any equations?

2.Is the Cgs in the DC print table showing the total parasitic capacitance between the gate and the source or the intrinsic one?

3.How come Cgs is not equal to Csg and why there are minus for capacitance? Capacitance should ignore the direction of measurement between two places. Maybe I have some misunderstanding.

Any response is highly appreciated.
Thank you.
Alex

OP("/I0" "??") = ?

signal            OP("/I0/MM0" "??")
betaeff              42.42m         
cbb                 240.1a          
cbd                 -20.86a         
cbdbo               -20.86a         
cbg                -404.4a          
cbgbo              -404.4a          
cbs                 185.2a          
cbsbo               185.2a          
cdb                  -3.269a        
cdd                 844.2a          
cddbo                20.26a         
cdg                -842.7a          
cdgbo               -18.81a         
cds                   1.812a        
cdsbo                 1.812a        
cgb                 -57.53a         
cgd                -735.2a          
cgdbo                88.76a         
cgg                   3.111f        
cggbo                 1.462f        
cgs                  -2.318f        
cgsbo                -1.493f        
cjd                   1.522f        
cjs                   3.15f         
covlgb                0             
covlgd              823.9a          
covlgs              824.6a          
csb                -179.3a          
csd                 -88.16a         
csg                  -1.863f        
css                   2.131f        
gbd                   1.869p        
gbs                   1.215p        
gds                 300.1u          
gm                    1.771m        
gmbs                295.1u          
gmoverid             13.61          
ibulk               -98.45f         
id                  130.1u          
ids                 130.1u          
igb                 211.1a          
igbacc              211.1a          
igbinv              576.8y          
igcd                162p            
igcs                175.3p          
igd                  84.91p         
igdt                811.7p          
igidl                 0             
igisl                 0             
igs                 389.5p          
pwr                  27.04u         
rdeff                11.63          
region                2             
reversed              0             
rgbd                  0             
ron                   1.597K        
rseff                12.51          
vbs                 -62.53u         
vds                 211m            
vdsat                82.18m         
vgs                 438.8m          
vth                 428m