CPD – Critical Point Dryer – Tousimis Autosamdri-815B (CPD-Autosamdri-815B)
Critical point drying (CPD) is well established method for wafer and MEMS drying. It reduces the effects of deformation and shrinkage that occur when drying wet samples by conventional evaporation.
With CO2 a critical point of approximately 35°C can be achieved at a pressure of around 83 bar. The sample is flooded with liquid CO2 and the temperature is then raised to above the critical temperature, the liquid CO2 changes to vapor without change of density and therefore without surface tension effects which distort morphology and structures.
Tousimis Autosamdri-815B CPD is designed for up 5 wafers up to size of 4” (100 mm) and is equipped with HF compatible wafer holders for sizes of 4“, 3” and 2”. Special basket for small samples (1 cm2) is also available.