electromigration

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hfooo1

Joined: 03 Nov 2007
Posts: 37

14 Nov 2007 3:52 asic fix electromigration

which tool can i use to check that my chip has an EM problem?
and how to fix it

btw , anyone can share some good layout webs

thanks in advance

shavakmm

Joined: 06 Oct 2007
Posts: 70
Helped: 3
Location: Bangalore

14 Nov 2007 7:29 voltage strom cadence

Astro rail from synopsys does EM analysis...it does all power analysis at physical level.... there are other tools available from Cadence etc... (sorry....i don't remember names of all those tools !)

For layout below website is very good:

http://vlsitechnology.org

rgds
murali
http://asic-soc.blogspot.com

hfooo1

Joined: 03 Nov 2007
Posts: 37

14 Nov 2007 12:49 Re: electromigration

hi
ask one more question
should i analyse EM after both floorplaned and routed? or others?
3x

cooldude040

Joined: 26 Oct 2007
Posts: 50

14 Nov 2007 16:30 electromigration

You can use Voltage Strom from cadence to rectify EM problems....
You can fix this by increasing the width of the metal
but if it is excceding too much then u need to metal slotting which is dividing the lines on the metal to reduce the weight so tht it will not destroy ur silicon dioxide..
Electromigration is the one which depends upon the current density and the tool automatically choses the current density from( i donno u find out and tell me important question) and then calculates.It is very difficult to say how the tool calculates unless u work on that
Bye take care

victoria_jitesh

Joined: 27 Nov 2006
Posts: 49
Helped: 1

15 Nov 2007 14:23 Re: electromigration

which tool can i use to check that my chip has an EM problem?
and how to fix it
In general to fix EM problems either :
1. increase metal width.
2. Use decoupling capacitor.

rania_hassan

Joined: 29 Apr 2005
Posts: 109
Helped: 8
Location: Egypt

15 Nov 2007 16:01 Re: electromigration

Also you follow the electromigration rules in the design documents of the kit you use

shavakmm

Joined: 06 Oct 2007
Posts: 70
Helped: 3
Location: Bangalore

16 Nov 2007 7:18 Re: electromigration

for power critical designs it is recommended to carry out EM analysis after power planning...... if you find EM problem you counteract with increasing the power net width etc as mentined in previous posts.

hence it is very important to do proper initial power analysis at front end itself so that physical design engineer can do proper power planning.

rgds
http://asic-soc.blogspot.com

ericyuan

Joined: 08 Mar 2006
Posts: 37
Helped: 1

16 Nov 2007 7:52 Re: electromigration

Does EM in PG net had some relationship with IRdrop?
acctually, it is current density, and related with Voltage, R C, right?

sekapr

Joined: 27 Jul 2006
Posts: 100
Helped: 5

02 Dec 2007 17:28 Re: electromigration

voltagestorm

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02 Dec 2007 17:28 Ads

devop

Joined: 05 Dec 2006
Posts: 87

30 Oct 2009 10:40 Re: electromigration

victoria_jitesh wrote:

which tool can i use to check that my chip has an EM problem?
and how to fix it
In general to fix EM problems either :
1. increase metal width.
2. Use decoupling capacitor.

can you explain how the decoupling capacitor fix the EM problems?

aliputa

Joined: 01 Nov 2009
Posts: 3
Location: China

01 Nov 2009 17:07 Re: electromigration

some small trick if there's some EM violation on the PG(power ground) nets.
1 increase metal width (said as others)
2 use double layers metal (maybe triple)
3 make some holes on these metal(a little effect)