Abstract: A method of applying a treatment liquid to a semiconductor wafer to form a coating include rotating a semiconductor wafer in its own plane within a hermetically-sealed container, discharging a cleaning fluid through a cleaning fluid nozzle onto the top surface of the wafer as it rotates, and then discharging a treatment liquid through a treatment liquid nozzle onto the center of the top surface of the wafer as it rotates. An apparatus for coating a treatment liquid on a semiconductor wafer comprises a hermetically-sealed container, a wafer chuck which rotates a semiconductor wafer in its own plane, a treatment liquid nozzle for connection to a supply of treatment liquid and discharging the treatment liquid onto the center of the top surface of the wafer as it rotates, and a cleaning fluid nozzle which is disposed to discharge a pressurized cleaning fluid onto the top surface of the wafer as it rotates.