Hi,

Can someone give a recipe to achieve aluminum passivation in 25%
TMAH.. We could achieve aluminum passivation in 5% TMAH doped with
35-40 gm/litre silicic acid... When i tried 25% TMAH with 160 - 200
gm/litre silicic acid, aluminum passivation could not be achieved.
Whether amount of silicic acid has to be increased further? moreover,
it took very long time for 160 - 200 gm/litre silicic acid to get
dissolved in 25% TMAH (1 litre) as compared to 35-40 gm/litre silicic
acid in 5% TMAH at the same temperature of 85 deg Celsius.

Thanks in advance.
A. Ravi Shankar,
Senior Research Scholar,
Microelectronics Lab,
Electronics &ECE Department,
IIT Kharagpur