Vapor Concentration Control
Vapor concentration control of precursors provide substantial improvement in stabilizing MOCVD processes. By measuring a precursor partial pressure in a downstream line with a Non Dispersive Infrared (NDIR) technology and controlling its total pressure, a precursor concentration can be kept constant. This precursor concentration control is validated as a practical method against a temperature fluctuation of a cylinder bath and a failure of reaching a saturation pressure in a cylinder.