MOM or MIM capacitor to use in SAR ADC

[RicardoA]

Hi all,

Can anybody tell me which capacitor (MOM or MIM) is better to use in a SAR ADC? And what are their main differences in terms of parasitic and mismatch?

Thanks in advance.

Regards
Ricardo Alves

 

[dick_freebird]

Oxide (MOM) is one kind of insulator (MIM) - what the
difference might be (if there is any, on the flow in question)
you'd have to peer into the foundry docs to know.

If "MOM" is using the full thickness of some ILD layer then
capacitance density will be poor and breakdown voltage
way, way more than you need, and the electrical dimension
will be set by your metal layers lithography and a fairly
sloppy thickness control. MIM is always a valued circuit
component and should have better CDs and thickness
tolerance on the dielectric.

But you first have to get past the dialect, to the facts
of construction -where you run it-.