how to design the probepad

[knightgreen]

hi
i design a schottky diode in standard process,and want test in probe test,but i don't
know how to design the probepad.i need you help!!!
thanks

 

[mdcui]

use a 4x4um or 5x5um top metal layer to form a sqare, then carve a smaller box 2x2u out of it to make it like a ring shape, usually probe tips are 0.2u, this kind of metal structure can be easily probed and tested. (make sure you don't have passivation layer over the top metal during processing)

 

[knightgreen]

thanks,but why should i carve a smaller box to make it like a ring shape?

 

[k_90]

I would draw it 9x9 or bigger if you can. The hole in the middle is used to help stop the probe from sliding over the silicon once its been located. Think of it as a pot hole in the road...once your in its hard to get out

K

 

[forkschgrad]

on what process it is applicable? i usually use 10umX10um using top metal sometimes up to the lowest level in 0.6um process.

 

[anisnn]

If you are using standard CMOS process, you can also use all metal layers and connect them with vias. This makes the probe pads thicker and less susceptible to have all its metal scraped off when probing.

You can also make the pad bigger so that it will be easier for you to probe it when using the microscope. My pads are usually 50u x 70u.

Also, don't forget to define the PAD layer on top of the probe pad, so that there will be no passivation layer covering it.

 

[hongmy]

I usually use 5umx5um with top metal,but we don't cut a hole mdcui said and It works good.
Anyway, I think mdcui is right,maybe we may have a try.

 

[leo_o2]

To measure schottky diode by probing, it will lead to error according to big contact resistance. It is better to measure by bonding.

 

[forkschgrad]

how is that?any illustrations?

 

[mdcui]

on aluminum process, we use 5x5 with a 2x2 hole inside pattern on top metal, since the top metal can be exposed, and the probe tip diameter we use is 0.2u, this metal ring makes it very easy to probe.
however in copper process, there will must a passivation layer covering all metal on top, to prevent contamination, in that case, simply use a 5x5 copper metal squre (without a hole in it) is good enough, because you will have to carve a window on that passivation layer, than landing a probe is also fine.

 

[shrbht]

on aluminum process, we use 5x5 with a 2x2 hole inside pattern on top metal, since the top metal can be exposed, and the probe tip diameter we use is 0.2u, this metal ring makes it very easy to probe.
however in copper process, there will must a passivation layer covering all metal on top, to prevent contamination, in that case, simply use a 5x5 copper metal squre (without a hole in it) is good enough, because you will have to carve a window on that passivation layer, than landing a probe is also fine.

the top metal has natural oxide surface, the probe must push into the metal. mdcui, how to probe the metal ring? thank u