MOM电容比MIM电容精度差很多么？

istart_2002

看某厂的文件：
MIM


SQRT(电容面积)=0.02um mismatch=0.01184%；对应信号失真比78.5dB;
MOM

SQRT(电容面积)=0.02um mismatch=0.3758%；对应信号失真比48.5dB;
这两种电容精度相差这么多么？

camelotking

the variation comes from (1) the gap between top/bottom plate, capacitor constant variation (2) edge of plate, size variation.

(1) MIM has more edge or MOM has more edge? every strip of MOM has edge.
(2) the layer between MIM is very thin, which is well controlled. This layer is not Oxide. The layer between M1/M2/M3/M4 are Oxide, which is not well controlled.