Scrub washing apparatus and scrub washing method

A scrub washing apparatus comprising:

• a mounting table for holding a substrate to be processed substantially horizontally;
• a scrub member, rotatable around a vertical axis, for scrubbing the substrate while the scrub member is in contact with the substrate on the mounting table;
• an output shaft having the scrub member connected to a lower portion thereof, for transmitting a rotational force around a vertical axis and a pressing force in the direction of the vertical axis;
• a horizontal arm for supporting the scrub member at an end thereof;
• a press mechanism attached to said end of the horizontal arm and connected to the output shaft for applying the pressing force to the output shaft;
• a vertical support connected to another end of the horizontal arm for supporting the press mechanism and scrub member in conjunction with the horizontal arm;
• a swing mechanism provided at said another end of the horizontal arm for swinging the horizontal arm around an axis of the vertical support;
• a cylinder mechanism that indirectly supports the vertical support via the swing mechanism for moving the vertical support along said axis of the vertical support together with the horizontal arm;
• a washing liquid supply mechanism having a supply tube extended from the vertical support and the horizontal arm, and having an opening immediately above the scrub member for supplying a washing liquid into said supply tube through the scrub member so as to apply the washing liquid to the substrate on the mounting table;
• a motor having a rotation drive shaft extending towards the output shaft in the lower portion;
• a drive engage member attached to a lower portion of the rotation drive shaft;
• and
• a driven engage member attached to an upper portion of the output shaft and engaged with the drive engage member, for transmitting the rotational driving force of the motor by way of the drive engage member, said driven engage member slidably moving up and down relative to the drive engage member.