An apparatus of supplying slurry for a planarization process includes a housing having a first side and a second side and channels extending through the housing from the first side to the second side along a first direction. The channels include a first channel connecting a first inlet on the first side and a first outlet on the second side, a second channel connecting a second outlet on the first side and a second inlet on the second side, a third channel connecting a third inlet on the first side and a third outlet on the second side, and a fourth channel connecting a fourth outlet on the first side and a fourth inlet on the second side. An intermediate portion of the second channel crisscrosses an intermediate portion of the third channel along a second direction crossing the first direction.