Substrate polishing system

A substrate polishing system comprising:

• a substrate transfer unit to support a bottom surface of a substrate and transfer the substrate while forming a transfer orbit in a circle by rotating;
• at least one carrier to perform polishing on the substrate received from the substrate transfer unit;
• and
• a loader to load the substrate which is seated on the substrate transfer unit to the carrier or unload a substrate placed on the carrier to the substrate transfer unit, wherein the loader comprises:
• a plurality of first nozzles to spray a fluid,
• a rotator to rotate on an axis perpendicular to a ground,
• a loading plate to support the bottom surface of the substrate, the loading plate being rotatable by the rotator, and
• a protrusion connected to an outside of the loading plate and protruding upwardly,
• wherein the plurality of first nozzles comprises a first inner nozzle and a second inner nozzle arranged on an inner surface of the protrusion,
• wherein, during a process of loading or unloading the substrate by moving the loader upward, an upper surface of the protrusion is placed higher than a bottom surface of the carrier, the first inner nozzle is located above the bottom surface of the carrier, and the second inner nozzle is located below the bottom surface of the carrier,
• wherein the substrate transfer unit comprises:
• a shaft to rotate on an axis perpendicular to the ground;
• and
• three transfer arms to support the bottom surface of the substrate and to transfer the substrate while forming the transfer orbit in the circle by rotation of the shaft,
• wherein the three transfer arms are configured to receive an unpolished substrate at a first point on the transfer orbit and to transfer the unpolished substrate to the carrier by moving to each of a plurality of second points on the transfer orbit, and configured to receive a polished substrate from the carrier at each of the plurality of second points and to transfer the polished substrate to the first point for a next process,
• wherein the three transfer arms are each disposed at an equiangular interval with the shaft as a center,
• wherein when one of the three transfer arms is placed on the first point, each of the other two transfer arms is placed on one of the plurality of second points,
• wherein the substrate polishing system further comprises a stage portion to support the substrate, wherein the stage portion is placed on the first point on the transfer orbit,
• wherein the stage portion comprises a second nozzle which sprays a fluid to an upper surface of the substrate located on the stage portion while the substrate is waiting to be transferred and sprays a fluid to the upper surface of the substrate while the substrate is located on the stage portion and while the stage portion and the second nozzle are moving vertically upward or downward to keep the substrate moist,
• wherein the plurality of first nozzles is configured to clean the carrier while the carrier is not gripping the substrate and to clean the carrier while the carrier is gripping the substrate, and
• wherein the first inner nozzle and/or the second inner nozzle spray a fluid on the carrier while the substrate transfer unit is transferring the substrate from one of the plurality of second points to another of the plurality of second points,
• wherein at least one of the plurality of first nozzles is further placed on an upper surface of the loading plate.