To withdraw automatically resist waste fluid in a waste fluid withdrawal bath outside a clean room, by a method wherein, if a waste fluid amount of a fluid reserving bath reaches a supremum, a waste fluid tube is opened by a switching valve, and the waste fluid in the fluid reserving bath is discharged through the waste fluid tube in a waste fluid withdrawal bath until it reaches a lowest limit in the bath.
A semiconductor wafer 1 is rotated at a high speed and resist is uniformly applied on the semiconductor wafer 1. At this time, after surplus resist (waste fluid) is received by a resist applying cup 2, it is dropped from a waste fluid hole 2A to a fluid reserving bath 3. The waste fluid is reserved in a waste fluid tube 8 with an automatic switching valve 9 first of all, and further the process for a plurality of semiconductor wafers 1 is repeated, so that the waste fluid is gradually reserved in the fluid reserving bath 3. If the waste fluid in the fluid reserving bath 3 is reserved up to a position of a supremum sensor 4, the automatic switching valve 9 is opened, and the waste fluid in the fluid reserving bath 3 is flown to a waste fluid withdrawal bath 7 through the waste fluid tube 8. If the waste fluid in the fluid reserving bath 3 is dropped up to a position of a lowest limit sensor 5, the automatic switching valve 9 is closed.
YASUHARA SHINICHI
TSUCHIYA TADATOSHI
SAITO SHINICHI
TOSHIBA CORP