Reasons for following low and high densities in layout

Status
Not open for further replies.
C

chandra Rao

Newbie level 3
Joined
Feb 9, 2007
Messages
3
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,300
Hi,
I want to know about reasons for following low and high densities in layout(like for metals)
So please explain me

Thanks inadvance
 

Regensity

reliability wise, u need a uniform metal distribution among the die so that during CMP all parts on the die is equally affected .
i guess from yield point of view u need a small gradient of metal change (i.e. the metal concentration should change with a small rate among the die.
 

Regensity

If you have an area with too low metal density, the covering oxide bends down and the vias connecting metals get disconnected.
 

Re: Regensity

planarization of layers is required to ensure a flat surface. if a certain layer doesn't have a flat surface, there is a tendency of the succeeding layers to have a curvature leading to breaks(microfracture). this is the reason why there is a minimum density of a certain layer.
hope it helps...
regards
 

Re: Regensity

Hi all,
Thanks for the reply.

According to all messages I understand that at the low density areas oxide layer over the metals gets bend down and succedding layers are effected ,
Please explain me how exactly it gets bend or give me any pdf on this.

Regards,
Chandra
 

Status
Not open for further replies.

Similar threads

Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…