Deposit conformal films without the need for high vacuum, onto substrates with irregular surfaces, or on large quantities of closely packed substrates. Chemical Vapor Deposition (CVD) is a process in which precursor gases react to form film deposits on a substrate. Source gases are supplied through a gas management system to the inlet of a heated quartz tube by forced and free convection. CVD is carried out at, or slightly below atmospheric pressure with flow rates in the laminar regime. As the gas flows over the substrate, shear forces slow the gas down resulting in a velocity gradient. Ultimately, the gas velocity drops to zero at the substrate and a boundary layer is formed. These factors combine to give CVD some advantages over typical Physical Vapor Deposition (PVD) processes. CVD is carried out at significantly higher pressures than PVD, eliminating the need for high vacuum pumps.
