Fluid supply device and wafer cleaning apparatus using the same

A fluid supply device comprising:

• a supply tank storing a liquid chemical;
• a supply tube connected to the supply tank;
• a supply valve provided at the supply tube;
• a branch tube connected to the supply tube;
• a first drain tube connected to the supply tube via the branch tube;
• a first drain valve provided at the first drain tube;
• a first provision tube connected to the branch tube;
• a first provision valve provided at the first provision tube;
• a first fluid tank connected to the first provision tube, wherein the liquid chemical is provided into the first fluid tank via the supply tube, the first provision tube, and the branch tube connecting the supply tube and the first provision tube with each other;
• a second drain tube connected to the first fluid tank to drain a liquid chemical in the first fluid tank;
• a second drain valve provided at the second drain tube;
• a second provision tube connected to the branch tube;
• a second provision valve provided at the second provision tube;
• a second fluid tank connected to the second provision tube;
• a third drain tube connected to the second fluid tank to drain a liquid chemical in the second fluid tank;
• a third drain valve provided at the third drain tube;
• and
• a controller configured to control opening and closing of each of the supply valve, the first drain valve, the first provision valve, the second drain valve, the third drain valve, to supply the liquid chemical from the supply tank to the first fluid tank or the second fluid tank,
• wherein, the controller is configured to perform:
• a first pre-draining operation, in which, during a time when the supply valve and the first drain valve are opened and the first provision valve and the second provision valve are closed, the liquid chemical is supplied via the supply tube from the supply tank to drain the liquid chemical detained in the supply tube and the liquid chemical supplied via the supply tube via the first drain tube for a preset time;
• a second pre-draining operation, in which after the first pre-draining operation is completed, during a time when the supply valve is opened and the liquid chemical is supplied via the supply tube from the supply tank some of the supplied liquid chemical is discharged via the first drain tube, and some of the supplied liquid chemical is supplied to the first fluid tank or the second fluid tank via the first provision tube or the second provision tube;
• and
• a liquid supplying operation, in which, after the second pre-draining operation is completed, during a time when the opened first drain valve is closed, the liquid chemical is selectively supplied to the first fluid tank or the second fluid tank via the supply tube and the first provision tube or the second provision tube.

A wafer cleaning apparatus comprising a fluid supply means and a cleaning means,

• wherein the fluid supply means comprises:
• a supply tank storing a liquid chemical;
• a supply tube connected to the supply tank;
• a supply valve provided at the supply tube;
• a branch tube connected to the supply tube;
• a first drain tube connected to the supply tube via the branch tube;
• a first drain valve provided at the first drain tube;
• a first provision tube connected to the branch tube;
• a first provision valve provided at the first provision tube;
• a first fluid tank connected to the first provision tube, wherein the liquid chemical is provided into the first fluid tank via the supply tube, the first provision tube, and the branch tube connecting the supply tube and the first provision tube with each other;
• a second drain tube connected to the first fluid tank to drain a liquid chemical in the first fluid tank;
• a first tank drain valve provided at the second drain tube;
• a second provision tube connected to the branch tube;
• a second provision valve provided at the second provision tube;
• a second fluid tank connected to the second provision tube;
• a third drain tube connected to the second fluid tank to drain a liquid chemical in the second fluid tank;
• a second tank drain valve provided at the third drain tube;
• and
• a controller configured to control opening and closing of each of the supply valve, the first drain valve, the first provision valve, the first tank drain valve, the second tank drain valve, to supply the liquid chemical from the supply tank to the first fluid tank or the second fluid tank,
• wherein the controller is configured to perform:
• determining whether or not the first fluid tank or the second fluid tank is filled with the liquid chemical;
• draining operation, wherein the first tank drain valve or the second tank drain valve is opened to drain the liquid chemical stored in the first fluid tank or the second fluid tank via the second drain tube or the third drain tube;
• a first pre-draining operation, in which, during a time when the supply valve and the first drain valve are opened and the first provision valve and the second provision valve are closed, the liquid chemical is supplied via the supply tube from the supply tank to drain the liquid chemical detained in the supply tube and the liquid chemical supplied via the supply tube via the first drain tube for a preset time;
• a second pre-draining operation, in which after the first pre-draining operation is completed, during a time when the first provision valve is opened the liquid chemical is supplied via the supply tube from the supply tank some of the supplied liquid chemical is discharged via the first drain tube, and some of the supplied liquid chemical is supplied to the first fluid tank or the second fluid tank via the first provision tube or the second provision tube;
• and
• a liquid supplying operation, in which, after the second pre-draining operation is completed, during a time when the opened drain valve is closed, the liquid chemical is selectively supplied to the first fluid tank or the second fluid tank via the supply tube and the first provision tube or the second provision tube, and
• wherein the cleaning means comprises:
• a support unit configured to support a wafer;
• a fluid supply unit configured to supply the liquid chemical from the first fluid tank or the second fluid tank;
• and
• a spray unit configured to spray the liquid chemical supplied by the fluid supply unit to the wafer in order to clean the wafer.