Optimization of cleaning process parameters to remove abrasive particles in post-Cu CMP cleaning *Project supported by the Major National Science and Technology Special Projects (No. 2016ZX02301003-004-007), the Natural Science Foundation of China (No. 61704046), the Scientific Innovation Grant for Excellent Young Scientists of Hebei University of Technology (No. 2015007), and the Hebei Natural Science Foundation Project (No. F2018202174). (December 2018)