Abstract: A rotatable cover plate assembly (10) has a cavity (13) and a rotatable base plate assembly (12) has a cavity (42) with a semiconductor wafer (14) mounted therein. The cover plate assembly (10) comes down onto the base plate assembly (12) enclosing the semiconductor wafer (14) and a dispenser (28) in a chamber formed by the cavities (13) and (42). The cover and base plates (16) and (40) are rotated as a single assembly, and coating material dispensed by the dispenser (28) onto the semiconductor wafer (14). A flow regulator (25) coupled via an exhaust manifold (20) controls the rate of evaporate of solvent from the dispensed coating material.