Realisation of membranes for atomic beam collimator by macropore micromachining technique (MMT)

The macropore formation in n-type silicon by electrochemical etching in hydrofluoric acid is an established technique. In this work we present the realisation and application of macroporous technology to realise a suspended membrane of 300 μm with pore of 5 μm right through the membrane. Double electrochemical reactor with a double electrolitical contact has been used. The necessary holes injection for the chemical dissolution is provided by illuminating the back contact of the wafer by halogen lamp. The membrane will be employed as an atomic beam collimator in an experiment of molecular and atomic spectroscopy. Other possible applications range from gas sensor to biomedical application.