Post-cmp cleaning apparatus and method

A brush for cleaning of substrates following chemical mechanical polishing of the substrates, the brush having a cylindrical base having an axis with a pair of ends, the cylindrical shape extending from end to end, and a plurality of nodules extending from the cylindrical base and being unitary therewith, the plurality of nodules having opposing axial end rows, the brush having an intended direction of rotation whereby each nodule has a forward side and a rearward side, the cylindrical base and nodules comprising a unitary porous foam structure, wherein at least one of the size of the nodules or the spacing of the nodules on the cylindrical base has gradient extending axially on the cylindrical base intermediate the two opposing end TOWS.

A brush for cleaning of substrates following chemical mechanical polishing of substrates, the brush having a cylindrical base having an axis with a pair of ends, the cylindrical shape extending from end to end, and a plurality of nodules extending from the cylindrical base and being unitary therewith, the brush having an intended direction of rotation whereby each nodule has a forward side and a rearward side, the cylindrical base and nodules comprising a unitary porous foam structure, wherein the plurality of nodules on the cylindrical base have two opposing end rows and wherein each cylindrical unit area of the cylindrical base intermediate the opposing end rows have a numerical density of the nodules, defined as the number of nodules per cylindrical unit area of the cylindrical base, and wherein the numerical density varies axially along the brush from one of the two opposing end rows to the other of the two opposing end rows, there being at least four changes in said numerical density.

A brush for cleaning of substrates following chemical mechanical polishing of substrates, the brush having a cylindrical base having an axis with a pair of ends, the cylindrical shape extending from end to end, and a plurality of nodules extending from the cylindrical base and being unitary therewith, the brush having an intended direction of rotation whereby each nodule has a forward side and a rearward side, the cylindrical base and nodules comprising a unitary porous foam structure, each of the plurality of nodules having a footprint and a footprint area, and wherein the plurality of nodules on the cylindrical base have two opposing end rows and wherein each cylindrical unit area of the cylindrical base intermediate the opposing end rows have an area density of the nodules, defined as the cumulative footprint area of nodules per cylindrical unit area of the cylindrical base, and wherein the area density varies axially along the brush from axially interior one of the two opposing end rows to axially interior the other of the two opposing end rows.