How to connect a parallel MOM capacitor in layout?

[fixrouter4400]

Hi there!

I need help with my layout..I'm doing an RF block with MOM(Metal-Oxide-Metal) Capacitor with M5 as top plate and M2 as bottom plate...

Can you help/show me sample layout how to connect a parallel MOM capa?

Thanks in advance!

 

[waxtomato]

mom capacitor layout

just like this

 

[Teddy]

capacitor mom

M5 is top and M2 is bottom??? that seems fishy.
Usually you have extra layer there to minimize insulator thickness. So M5 and M4 look right. Unless you are trying your own cap with a small capacitance.

 

[fixrouter4400]

mim mom capacitor

I'm not sure why the circuit designer chose the M5-M2 mom capa...because his trying to connect the top plate M5 to one end of inductor which is M6 metal and the other end connected to bottom plate is the NMOS RF transistor using M2.

What do you think of this guys?

Thank you for the help teddy and waxtomato and to all who's willing to share there 2 cents knowledge

 

[Teddy]

inductor capacitor layout

It does seem strange. Usualy the Mim cap (MOM) is under top level metal (in this case as you say M6)
So the cap connection would be M5 and M6. Then M6 to inductor and down with vias to active devices. but I never seen M2-M5 cap

 

[fixrouter4400]

mom cap layout

It does seem strange. Usualy the Mim cap (MOM) is under top level metal (in this case as you say M6)
So the cap connection would be M5 and M6. Then M6 to inductor and down with vias to active devices. but I never seen M2-M5 cap

Hi Teddy - I'm not pretty sure that MIM CAP and MOM CAP are the same in terms of layout structures...the construction of MOM CAP pls see sample layout

As I see in the layout MIM CAP use only 2 metal layers while in the MOM CAP they use as many as they want depending on the ckt designer if he want's to use M6-M2 or M5 - M2 (Top and bottom plate). For this particular design they want

 

[Jackon521]

capasitor layout

hi fixrouter4400,
I have one problem, now i have designed a pipeline ADC, and sucessful tape out, but now i want to replace the MIM cap with MOM cap.
because i have no spice model of MOM cap, and there are no LVS rules of MOM. i am using SMIC18 tech, so it's tough to make it.
could you please tell me how can i get start, and what should do from ZERO, if you can.
Thank you very much