During surface micromachining, stiction or adhesion between the substrate (usually silicon-based) and the microstructure occurs during the isotropic wet etching of the sacrificial layer. The capillary forces due to the surface tension of the liquid between the microstructure and substrate during drying of the wet etchant cause the two surfaces to adhere together. Separating the two surfaces is often complicated due to the fragile nature of the microstructure. Stiction is often circumvented by the use of a sublimating fluid (often supercritical CO, which has extremely low surface tension) drying process where the liquid phase is bypassed. CO displaces the rinsing fluid and is heated past the supercritical point. As the chamber pressure is slowly released the CO sublimates, thereby preventing stiction.