Hi, Elena

You can use a larger water bath to put your TMAH container in and heat
up the whole bath, that will give you a very uniform temperature
control.

Liwei

>>> [email protected] 04/19/05 1:41 PM >>>
Does any one know of heaters (say a ceramic plate that is
submerged vertically in solution) that provide uniform
temperature throughout the etching solution? I am doing a
back side etch on an 8'' wafer, using a very large container
filled with TMAH, but the wafer etches differently at the
bottom and at the top.