Non-contact pad cleaning apparatus

A non-contact pad cleaning apparatus for cleaning a polishing surface of a polishing pad for polishing a workpiece in a non-contact manner, comprising:

• a rotary table configured to rotate the polishing pad;
• a polishing-surface cleaning device having a plurality of two-fluid nozzles each configured to emit a two-fluid jet toward the polishing surface of the polishing pad;
• and
• a liquid supply line and a gas supply line coupled to the plurality of two-fluid nozzles,
• wherein the polishing-surface cleaning device comprises:
• the plurality of two-fluid nozzles having a plurality of ejection ports, respectively, the plurality of ejection ports being configured to emit the two-fluid jet;
• a nozzle carrier holding the plurality of two-fluid nozzles;
• and
• an upstream-side nozzle cover and a downstream-side nozzle cover fixed to the nozzle carrier,
• wherein the plurality of ejection ports are arranged at different distances from a center of the polishing pad,
• the upstream-side nozzle cover is arranged upstream of the plurality of two-fluid nozzles in a rotation direction of the polishing pad,
• the downstream-side nozzle cover is arranged downstream of the plurality of two-fluid nozzles in the rotation direction of the polishing pad, and
• a distance from the polishing surface to a lower end of the upstream-side nozzle cover is larger than a distance from the polishing surface to a lower end of the downstream-side nozzle cover.