The Supercritical Drier is a system for rinsing typically a MEMS device after sacrificial layer etch.  If the HF etchant was rinsed with water and dried, the surface tension of the water could pull structures such as cantilevers into contact with other parts resulting in bonding which would not allow movement of the MEMS part.  The Superciritical Point Drier uses liguid CO2 to displace the fluid (the HF is first displaced with alcohol), the CO2 is then heated to change to a gas.  This dries and rinses the MEMS device without damaging the components of it.

The CO2 transition is accompanied by a pressure rise to as high as 1500 psi.  Therefore the Drier has thick steel casing and multiple strong bolts holding the lid on.

User Manual coming soon...



Updated: 2008-04-24