Methods and apparatuses for mechanical and chemical-mechanical planarization of microelectronic-device substrate assemblies on planarizing pads

A planarizing machine for planarizing microelectronic-device substrate assemblies, comprising:

• a table;
• a planarizing pad removably positioned on the table and having a planarizing surface facing away from the table;
• a carrier assembly having a substrate holder positionable over the planarizing pad and being rotatable about a first rotational axis and having a planarizing solution dispenser to dispense a fresh planarizing solution onto the planarizing surface, the substrate holder translating a substrate assembly over a planarizing zone of the planarizing surface during a planarizing cycle, and the substrate assembly pushing used planarizing solution deposited onto the planarizing pad into an accumulation zone on the planarizing surface adjacent to the planarizing zone;
• and
• a planarizing solution removing unit at the accumulation zone, the removing unit including a rotating brush extending across at least a portion of the accumulation zone, the rotating brush being coupled to the carrier assembly and spaced apart from the substrate holder, the rotating brush being separately rotatable about a second rotational axis approximately perpendicular to the first rotational axis to actively remove used planarizing solution from at least a portion of the accumulation zone on the stationary planarizing pad, wherein the brush further includes a plurality of non-abrasive bristles.