Thin wafer etching help request

[Jack Kotovsky]

Hello STS users;

I'm having difficulty successfully etching 70um thick (4" diameter)
wafers in the STS.  I would greatly appreciate suggestions for improving
my technique.

I have failed at my first 3 attempts to etch the thinned wafers.  Two of
the three were mounted on handle wafers with resist (following the SNF
wafer mounting guidelines on the webpage) and the third was taped to the
handle.  The wafers suffered from loss of resist during etch due to
improper cooling and/or cracking during the process (perhaps due to
trapped air expanding on pump-down).

Can you suggest a working technique for through-etching of thinned wafers?

Thank you kindly for the help, Jack

	Jack Kotovsky 			(H) (530) 758-6278

    I went on a diet, swore off drinking and heavy eating, and in
    fourteen days I had lost exactly two weeks. -- Joe E. Lewis