Layout error: the minimum overlap of M1 ground plate to LSM is 10um.

[deepa]

"THe minimum overlap of M1 ground plate to LSM is 10um."This is error i get in my layout.I have used 2 caps of 1pF each (MIMCAPS).
What does this mean and how to correct this

 

[layoutmaster]

layout error

By following standard DRC jargon, I would say that M1 ground plate MUST overlap your LSM in at least 10 um and you're having an overlap that's smaller than that...

To correct that you must draw an overlap of layer bigger than 10um. I don't know your CAP/AREA but probably you'll need to create your 1pF by using 2x 2pF in parallel...

 

[shwetarao]

Re: layout error

hey

why cant we just layout a single 1pFcap?why do we need to layout two 2pF caps in parallel?

-shweta

 

[layoutmaster]

layout error

I´m not saying you can't do a single 1pF cap.

Probably the DRC error was based on how the cap was made (as soon as in one direction you have an overlap between metals below the required 10um, you'll have the error)

With my comment, what I was trying to say was that, if your process data makes that a 1pF cap need metal plates small enough to have a DRC error as mentioned (I don't think so, but...) you would need to use a bigger unit cell (for instance a 2pF cap) in order to avoid the DRC violation and create the 1pF one by using two parallel 2pF ones. Is it clear now?

 

[shwetarao]

Re: layout error

yeah thanq