Method of manufacturing grooved chemical mechanical polishing layers

摘要

A method of manufacturing grooved polishing layers for use in chemical mechanical polishing pads is provided, wherein the formation of defects in the polishing layers are minimized.

主权项

1. A method of manufacturing a polishing layer with a grooved polishing surface for use in a chemical mechanical polishing pad; wherein the method comprises:
providing a polishing layer with an ungrooved polishing surface, wherein providing the polishing layer with an ungrooved polishing surface comprises:
providing a mold, having a mold base and a surrounding wall attached to the mold base;providing a liner with a top surface, a bottom surface and an average thickness of 2 to 10 cm;providing an adhesive;providing a curable material comprising a liquid prepolymer and a plurality of microelements;providing a nozzle, having a nozzle opening;providing a skiver blade with a cutting edge;providing a strop;providing a stropping compound;bonding the bottom surface of the liner to the mold base using the adhesive,wherein the top surface of the liner and the surrounding wall define a mold cavity;wherein the top surface of the liner defines a horizontal internal boundary of the mold cavity, wherein the horizontal internal boundary of the mold is oriented along an x-y plane, wherein the mold cavity has a central axis, Caxis, that is perpendicular to the x-y plane, and wherein the mold cavity has a doughnut hole region and a doughnut region;charging the curable material through the nozzle opening to the mold cavity during a charging period, CP, wherein the charging period, CP, is broken down into three separate phases identified as an initial phase, a transition phase and a remainder phase;wherein the nozzle opening has a location and wherein the location of the nozzle opening moves relative to mold base along the mold cavity's central axis, Caxis, during the charging period, CP, to maintain the location of the nozzle opening above a top surface of the curable material in the mold cavity as the curable material collects in the mold cavity; wherein the location of the nozzle opening resides within the doughnut hole region throughout the initial phase; wherein the location of the nozzle opening transitions from residing within the doughnut hole region to residing within the doughnut region during the transition phase; and, wherein the location of the nozzle opening resides within the doughnut region during the remainder phase;
wherein the mold cavity approximates a right cylindrically shaped region having a substantially circular cross section, Cx-sect; wherein the mold cavity has an axis of symmetry, Cx-sym, which coincides with the mold cavity's central axis, Caxis; wherein the right cylindrically shaped region has a cross sectional area, Cx-area, defined as follows:
Cx-area=πrC2, wherein rC is the average radius of the mold cavity's cross sectional area, Cx-area, projected onto the x-y plane; wherein the doughnut hole region is a right cylindrically shaped region within the mold cavity that projects a circular cross section, DHx-sect, onto the x-y plane and has an axis of symmetry, DHaxis; wherein the doughnut hole has a cross sectional area, DHx-area, defined as follows:
DHx-area=πrDH2, wherein rDH is a radius of the doughnut hole region's circular cross section, DHx-sect; wherein the doughnut region is a toroid shaped region within the mold cavity that projects an annular cross section, Dx-sect, onto the x-y plane and that has a doughnut region axis of symmetry, Daxis; wherein the annular cross section, Dx-sect, has a cross sectional area, Dx-area, defined as follows:
Dx-area=πRD2−πrD2 wherein RD is a larger radius of the doughnut region's annular cross section, Dx-sect; wherein rD is a smaller radius of the doughnut region's annular cross section, Dx-sect; wherein rD≧rDH; wherein RD>rD; wherein RDallowing the curable material in the mold cavity to cure into a cake, wherein the curable material bonds to the liner;separating the surrounding wall from the mold base and the cake;applying the stropping compound to the cutting edge;stropping the skiver blade with the strop; and, slicing the cake to provide the polishing layer with an ungrooved polishing surface using the skiver blade; first machining at least one curved groove into the ungrooved polishing surface; and, then machining a plurality of linear grooves in an XY grid pattern into the polishing surface to produce the polishing layer with a grooved polishing surface;
wherein the plurality of linear grooves are machined by a step down process, wherein a groove cutting tool makes multiple successive cutting passes to form each linear groove, and, wherein each successive cutting pass increases the depth of the linear groove being formed.