Wet Etching: Tandem Series

Unique wafer holders for two wafers mounted face-to-face.

The Tandem series wafer holders are designed for single-side etching processes which do not require electrical contacts, (e. g. time based etching, etch-stop on oxide or nitride layers, SOI wafers, glass and quarz wafers etc.)

Tandem series wafer holders are used for more than 15 years in MEMS industry and research and have convinced over 100 users of their reliability and engineering quality.

A unique feature of AMMT's Tandem series wafer holders is their symmetrical and small footprint construction that allows to mount two wafers facing each other into one holder. As a consequence, even a small etchant bath can be used to etch a number of wafers simultaneously. If only one wafer needs to be processed, a Pyrex glass wafer can be mounted into the second slot as dummy cover.

Each wafer is sealed by a double precision O-ring system that reduces mechanical stress on the wafer to a minimum. Two cover rings on the front and back side hold the wafers in place.

As the customer-specific wafer thickness is machined as a recess into the cover ring, all screws can be tightened using a regular wrench without sensitivity to the applied torque. This assures a minimum of mechanical stress to the fragile wafer.

Tandem series wafer holders are available for 3”, 4”, 5”, 6” and 8” wafers. Please inquire for other wafer sizes or individual outline dimensions.