The Automegasamdri®-936 Critical Point Drying (CPD) tool is used for carbon dioxide (CO2) drying after release of bulk or surface micromachined devices. Critical point drying is an efficient method of drying delicate samples without damaging it's structure by surface tension that occurs when changing from the liquid to the gaseous phase. The release is usually performed by immersion of the device in hydrofluoric acid followed by subsequent immersions in several beakers of DI water. The CPD requires that the device be completely free of acid or water before introducing it to the chamber. To avoid this, the device should be placed in isopropyl alcohol for at least one hour.
CO2 drying after release of micromachined devices