You can try the SEZ backside etch system
The whole name of the company is Semiconductor Equipment und Zubehor AG, it
is in german
the address is:
                        Draubodenweg 29
                        A-9500 Villach
                        Phone 43/4242/204-0
                        Fax 43/4242/204-21
> ----------
> From:
> OLIVIER.LEFORT@cpt.val.sextant.thomson-csf.com[SMTP:OLIVIER.LEFORT@cpt.val
> .sextant.thomson-csf.com]
> Reply To:
> OLIVIER.LEFORT@cpt.val.sextant.thomson-csf.com;mems-cc@ISI.EDU
> Sent:         12 March 1999 20:54
> To:   MEMS@ISI.EDU
> Subject:      Looking for single side wet etching tools
>
> Dear MEMS community,
>
> We are currently looking for tools for silicon wet etching of 4" wafer in
> KOH with a proteection of one (active) side of the wafer.
>
> We need a highly reliable mechanical tool for our production line, with
> very low induced mechanical stress.
>
> Does anyone know a qualified supplier for such a tool?
>
> Regards
>
> Olivier LEFORT
> Microsensor design manager
> Sensor Unit
> SEXTANT Avionique
> Phone : 33 4 75 79 85 19
> Fax : 33 4 75 79 86 06
> olivier.lefort@sextant.thomson-csf.com
>
>