If the peroxide concentration in the SC-1 drops too low, then it is known that
the silicon surface can be etched by the ammonia. Polycrystalline and amorphous
silicon are much more sensitive to this phenomenon.

L.Goodman
Sarnoff Corp.

-----Original Message-----
From: Fradkin Evgenia - Golda [mailto:evgeniaf@rafael.co.il]
Sent: Thursday, October 21, 2010 3:04 AM
To: 'mems-talk@memsnet.org'
Subject: [mems-talk] Damaged wafers after SC1 clean

Hello,

We've encountered a serious damage to the wafers surfaces during SC1 cleaning
process.  A picture of a damaged silicon wafer after the cleaning process is
attached.
This damage occurs only for wafers from a certain vendor.

It seems that wafers from other vendors are damaged as well if being cleaned in
the same solution after the said damaged wafers.

Have anyone encountered such a problem before? Can you suggest what might be the
cause?

Thanks,

Evgenia