what is the difference between filling dummy metal and real metal?

[guow06]

I am doing metal filing for a comparator. Just wonder what is the difference between dummy metal and real metal.
1) Will all the dymmy metal be fabricated? or it is optional for the foundry. (I want the layout be symmetrical. so if it is optional, I would prefer real metal insted of dummy one)
2) when do the QRC, will dummy metal be counted?

 

[JoannesPaulus]

1) Yes! Dummy metal is fabricated. Dummy metal is real metal, it is called "dummy" because it is not connected to anything. It is used, among other things, to improve matching and to have uniform planarization.
2) Yes.

 

[cop02ia]

Hi,

Usually mask layer will merge dummy & normal drawing metals using equation Metal1 = Dummy_Metal1 OR Drawing_Metal1.
I believe the original concept of automatically creating dummy metals for fill shapes was the reason Dummy layer type was created.
If the fill shapes were to be automatically created, then there would be an easy way of removing them if the fill procedure gave incorrect/undesireable results.
Having said that, I would prefer to use drawing type layer, in case a fill procedure is used (& then reversed) later.

Best regards,
I-FAB

 

[guow06]

thanks very much for your answering.
same as I thought.

 

[mamadmn]

Hi,
If dummy and metal are similar, Why I have DRC error without using dummy? I mean I added metal instead of dummy metal but there is a DRC error.
Can anybody introduce a reference for me?
Thank you