What is Fringe capacitance in Layout

[jagadeesh2k1]

Can any one of u explain what is fringe capacitance in layout?

 

[zeeshanzia84]

It the unintentional capacitance that creeps into your design whenever there are two metallic lines in parallel with dielectric in between.

 

[jagadeesh2k1]

Can u explain what is Lateral capacitance

 

[RDRyan]

You mean finger capacitance in layout?
Finger capacitance is like two combs that fit together.
or your mean parasitical capacitance in layout?

 

[jerryzhao]

The capacitor top and bottom plane have some thichness that relate to process technolog. there a capacitor between the top plane's lateral and bottom plane.
detail shown in figure.

 

[srieda]

The electric field lines in a parallel plate capacitor are parallel wrt each other. But near the edges of the parallel plates, the charge distribution is non-uniform and hence the field lines are bent.. this effect is called fringe effect...

A similar thing happens between any 2 metal layers in the layout. The places where the plates are planar-parallel, u get uniform electric flux which will lead to coupling capacitances. the regions where the electric lines of force experience fringe, contribute to the fringe effect.
For eg, between a metal1 of 2u width and a metal2 of 1u width running in parallel can cause fringe cap...

hope this helps..

 

[jagadeesh2k1]

Is it between different layers or between met1 and met1.

 

[analayout]

hi
good explanation by srieda

thanks
regards
analayout

 

[jerryzhao]

Is it between different layers or between met1 and met1.

Both.