Which reliablity items should be tested for backside metallization process?

[ohlargeone]

Which reliablity items should be test for backside metallization process?
and how to test?
My conpany is a wafer foundry. We are setting up new process on backside meatallization process for DMOS.

[chergh]

As there seems to be a big thing about acronyms I will first put DMOS is a Diffusion Metal Oxide Semiconductor.

As for you reliability items I have the following opinions, worked in semicon a while back so my memory may be abit dodgy.

You will probably want to measure metal layer thickness, wafer bowing, wafer stress and how well it bonds with solder. How you are going to do these I am not sure but I am sure you must have equipment for most of these in your facility, you may need to rely on data from the front end processes for the solder bond item.

If you explain what reliability issues you are having we may be able to help more.

[Michael Walmsley]

Here is an easy read.
http://www.weibull.com/mil_std/mil_hdbk_338b.pdf

[ohlargeone]

Originally Posted by chergh

As there seems to be a big thing about acronyms I will first put DMOS is a Diffusion Metal Oxide Semiconductor.

As for you reliability items I have the following opinions, worked in semicon a while back so my memory may be abit dodgy.

You will probably want to measure metal layer thickness, wafer bowing, wafer stress and how well it bonds with solder. How you are going to do these I am not sure but I am sure you must have equipment for most of these in your facility, you may need to rely on data from the front end processes for the solder bond item.

If you explain what reliability issues you are having we may be able to help more.

Thanks for your comments.
our metallization process:backside wafer griding+metal vapour(Ti+Ni+Ag)
and bacside wafer griding + backside metal sputter
the potential issue we are worried about is backside metal peeling.
so how to qualify it and monitor it?