CMP solutions for 3D-NAND staircase CMP

As NAND technology is moved from 2D to 3D, there are a few CMP steps to be newly added such as channel poly CMP and staircase (or ILD) CMP. Channel poly CMP is to polish many materials simultaneously such as SiN, oxide and poly-Si therefore it needs individual material rate tunability to meet final topography requirement. Staircase CMP process is identical to conventional ILD or IMD CMP but it needs high planarization efficiency (PE) and fast removal rate (RR) in order to meet higher step height and huge oxide removal amount. This study is to deal with slurries of 3D-NAND device integration having the rate tunability of various materials for channel poly and the high performance on PE and oxide rate for staircase CMP.