Hmaly,
Re: " ...Don't both buy close to the same filters and use close to the same clean
room processes. In particular, if AMD did have a DD problem, couldn't AMD
simply upgrade the clean room and filtering system ..."
You are over-simplifying the problem. Hard defects can be caused by
any piece of equipment in the cleanroom. It can be due to impure
incoming material (gases, liquids, ...), it can be due to the equipment recipe
being used (power, pressure, slurries, ...), it can be caused by the
environment (filters, wafer handlers, ...), the list can go on and on.
This is why "Copy Exactly" is so important to achieve the same yield/defect density
in different Fabs.
Make It So,
Yousef |
