Substrate cleaning method, substrate cleaning system and program storage medium
A substrate cleaning method can uniformly removing particles from substrates at a high removing efficiency. The substrate cleaning method includes the steps of immersing substrates W in a cleaning liquid in a cleaning tank 12 , and generating ultrasonic waves in the cleaning liquid contained in the cleaning tank. A region in the cleaning tank toward which the cleaning liquid is supplied is varied with respect to a vertical level in the step of generating ultrasonic waves in the cleaning liquid while the cleaning liquid is being supplied into the cleaning tank.
1. A method of substrate cleaning with a cleaning tank, an ultrasonic generator and a plurality of supplying members with each supplying member of the plurality being positioned at a different vertical level within the tank, said method comprising the steps of:
immersing a semiconductor wafer in a cleaning liquid in the cleaning tank;
generating, with the ultrasonic generator, ultrasonic waves in the cleaning liquid while causing the plurality of supplying members to supply cleaning liquid into the tank; and
during generating of ultrasonic waves and while the plurality of supplying members are supplying cleaning liquid,
changing a cleaning liquid supply rate of at least one supplying member so as to change the amount of cleaning liquid supplied at the level corresponding to said at least one supplying member,
changing a cleaning supply rate of at least another supplying member so as to change the amount of cleaning liquid supplied at the level corresponding to said at least another supplying member, and
causing different members of the supplying members to simultaneously supply the cleaning liquid at different dissolved gas concentrations.
2. The substrate cleaning method according to claim 1 , wherein bubbles are supplied together with the cleaning liquid into the cleaning tank through at least one of the supplying members in the step of generating ultrasonic waves in the cleaning liquid while the cleaning liquid is being supplied into the cleaning tank, and
a bubble supplying rate at which the bubbles are supplied through said at least one of the supplying members is varied in the same step.
3. The substrate cleaning method according to claim 1 , wherein bubbles are supplied together with the cleaning liquid into the cleaning tank through at least one of the supplying members in the step of generating ultrasonic waves in the cleaning liquid while the cleaning liquid is being supplied into the cleaning tank, and
the number of bubbles supplied in a unit time through said at least one of the supplying members is varied in the same step.
4. The substrate cleaning method according to claim 1 , wherein a first supplying rate at which the cleaning liquid is supplied through a first of the supplying members and a second supplying rate at which the cleaning liquid is supplied through a second of the supplying members are different, the first of the supplying members and the second of the supplying members being disposed at a different vertical position within the cleaning tank.
5. The substrate cleaning method according to claim 1 , wherein bubbles are supplied together with the cleaning liquid into the cleaning tank through at least two of the supplying members in the step of generating ultrasonic waves in the cleaning liquid while the cleaning liquid is being supplied into the cleaning tank, and
a bubble supplying rate at which the bubbles are supplied through a first of the at least two supplying members and a bubble supplying rate at which the bubbles are supplied through a second of the at least two supplying members are different, the first of the at least two supplying members and the second of the at least two supplying members being disposed at a different vertical position within the cleaning tank.
6. The substrate cleaning method according to claim 1 , wherein bubbles are supplied together with the cleaning liquid into the cleaning tank through at least two of the supplying members in the step of generating ultrasonic waves in the cleaning liquid while the cleaning liquid is being supplied into the cleaning tank, and
the number of bubbles supplied in a unit time through a first of the at least two supplying members and the number of bubbles supplied in a unit time through a second of the at least two supplying members are different, the first of the at least two supplying members and the second of the at least two supplying members being disposed at a different vertical position within the cleaning tank.
7. A storage medium storing a program to be carried out by a control device for controlling a substrate processing system so as to accomplish a substrate processing method according to claim 1 .
8. The substrate cleaning method according to claim 1 , wherein the dissolved gas concentration of the cleaning liquid supplied through at least one of the supplying members is varied in the step of generating ultrasonic waves in the cleaning liquid.