Belford,

Please confirm that it is H2So4 added to H2O2, instead of H2O2 added to
H2So4, which might be dangerous.

Good luck,

Hongjun Zeng
MEMS/Nano Scientist
Microfabrication Application Laboratory(MAL)
University of Illinois at Chicago

-----Original Message-----
From: Sumant Sood
Subject: RE: [mems-talk] About the Piranha cleaning

Zhiwei,
For Piranha, I add 1 part of H2O2 (30%) to 3 parts concentrated H2SO4. The
reaction is exothermic and the solution heats up for the first few minutes.
Once the solution cools down, you can heat it upto 130 deg C for cleaning.