PURPOSE: A deep filter for filtering slurry from a chemical mechanical planarization (CMP) process is provided to attenuate the fibers of a filtering material layer while maintaining the average diameter of pores in a filtering material. CONSTITUTION: The multiple filtering layers have asymmetric pore gradient such that the average diameter of pores gradually increases from the inner core to the outer circumference of the multi-layered filtering part. Fibers in a deep filtering material are attenuated while the average diameter of pores in a filtering material for the multi-layered filtering part is maintained. The average diameter of pores in the filtering material is in a range of 1-30um.
