Handling large current without electron migration?

[xiexi]

About electron migration

I have read one sentence but I don't know the meaning.
"The metal should be big enough to handle that large current without electron migration."
Can anyone tell me, thanks.

 

[srieda]

Re: About electron migration

I think this is related to the Cu damascene process employed for fabrication. The alloys of Cu which is used for interconnects are prone to this defect. The current process has a problem that when the current density is high, the kinetic energy of the electrons can, under certain conditions, can impart enough energy to the Cu-alloy molecules so that they clung on. This can cause certain bad effects such as an open-circuit or shorting with a nearby interconnect.. This is one of the reliability issues concerned with the Cu damascene process...
In order to ensure that this effect is nullified to a great extent, it is advisable to use wide metals...

I am a design engineer... So layout and fab guys, kindly correct me if i am wrong...

 

[penchal_gv]

Re: About electron migration

If you refer your design rule deck, that will how much current will carry for one micron width of metal.
So we will calculate width of metal according to current requirement.
apart from we will also consider IR drop for metal width calculations.
please correct me if i am wrong.

 

[leohart]

Re: About electron migration

I think this is related to the Cu damascene process employed for fabrication. The alloys of Cu which is used for interconnects are prone to this defect. The current process has a problem that when the current density is high, the kinetic energy of the electrons can, under certain conditions, can impart enough energy to the Cu-alloy molecules so that they clung on. This can cause certain bad effects such as an open-circuit or shorting with a nearby interconnect.. This is one of the reliability issues concerned with the Cu damascene process...
In order to ensure that this effect is nullified to a great extent, it is advisable to use wide metals...

I am a design engineer... So layout and fab guys, kindly correct me if i am wrong...

I think Al is more prone to eletron migration,add Cu to Al can reduce the effect...

 

[CK815]

Re: About electron migration

You are correct. AlSi is more prone to e- migration than AlCuSi/AlCu or "pure" copper. However, several methodes are used to minimize the effect in Al metallizations. Ti/TiN or Ti/TiN/Ti liners for example are used for W- vias and contacts or even on top and bottom of Al metal interconnects.

Regards,

C

 

[rajkumaru]

Re: About electron migration

I have read one sentence but I don't know the meaning.
"The metal should be big enough to handle that large current without electron migration."
Can anyone tell me, thanks.

If the current flowing through a metal is greater than the current carrying capability of that metal,there happens a collision among the electrons which produces heat due to the collision which makes the metal gets melted causing a open circuit.

 

[ionutz19821]

Re: About electron migration

Electromigration causes wearout of metal interconnect through the formation of voids.
High current densities lead to an 'electron wind' that causes metal atoms to migrate
over time.
It depends on the current density J. Current limits are usually expressed as a maximum Jdc.
More likely to occur for wires carrying DC currents.

 

[analayout]

Re: About electron migration

hi
electron migration means burning of metal layers due to excess current
you have to ensure that the metal width is sufficient to aviod electro migration
the current handling capacity of each metal you can get from design manual

hope that this will help you

regards

analayout

 

[Abbigeri]

About electron migration

below is the link to electromigration video, but am not able to open it. can anyone open it

https://www.doitpoms.ac.uk/tlplib/electromigration/damage.php

 

[Blackuni]

Re: About electron migration

Hi,

I am able to open it. I used Quick time player.

That link helped to learn

Thanks

 

[stuck_adc]

Re: About electron migration

if large current is flowing through a metal, then it provides enough energy to the electron in the metals, that they can leave the metal thus creating voids in the metal which cause hysteresis and damage the metal, and cause lot of heat dissipation.....
so inorder to avoid this the metal width should be large enough to hold the large current and avoid the electron migration.

 

[Abbigeri]

About electron migration

hi

refer to this :



regards
abbi

 

[srieda]

Re: About electron migration

hi

refer to this :



regards
abbi

one of the videos was corrupt in the rapidshare website database itself i think... but i have attached the other 2 videos in this....

 

[Teddy]

About electron migration

simply said the matal paricles move as current is flowing through them. THis is part of reliability testing (500 hrs at high temp). Since the metal particles are moving it is good ideal for high current paths make bigger overlap over contacts and vias. Also to use wider metals (rule of thumb 1um - 1mA)
IBM has very good design rules for this and good explanations. Can't place those here for copyright reasons....

 

[piao]

About electron migration

you can find from the web that eletron migaration will depend on the DC current.