Abstract: A method for fabricating semiconductor device is disclosed. The method includes the steps of: providing a substrate having a memory region and a periphery region; forming a memory cell on the memory region; forming a first polysilicon layer on the periphery region and the memory cell; forming a patterned cap layer on the periphery region; forming a second polysilicon layer on the first polysilicon layer and the patterned cap layer; and performing a chemical mechanical polishing (CMP) process to remove the second polysilicon layer, wherein the chemical mechanical polishing process comprises an abrasive of greater than 13% and a remove rate of less than 30 Angstroms/second.

Abstract: A wet cleaning process is provided. The wet cleaning process includes at least one first rinse process and a second rinse step. The first rinse step includes rinsing a substrate using deionized water containing CO2, and then draining the water containing CO2 to expose the substrate in an atmosphere of CO2. The second rinse step includes rinsing the substrate using deionized water containing CO2.