The manufacturing of semiconductor devices relies on four basic operations: layering, patterning, doping, and heating. The focus of this review is obviously on scCO2 cleaning. The chapter provides some background information on the characteristics of supercritical fluids and their related solvation properties, with an emphasis especially on scCO2. It discusses the novel applications of scCO2 in the semiconductor cleaning process and recent advances in the emerging technology. The final step is the removal of sacrificial oxide layer which is done usually through wet etching with an aqueous HF solution, followed by rinsing in deionized water and drying. The CO2-based drying is also particularly useful in the removal of water and other contaminants from microelectromechanical structures (MEMS)-based devices.125,148-150, the procedure was found to be convenient in preventing stiction and collapsing which often occur in MEMS devices following their final release etch.