Sidewall attack is one of the main defects in Al-Cu interconnect process.This defect will cause EM issue,and reduce the reliability of device.During plasma PR striping process θ phase Al2Cu granule form in the metal line surface due to precipitate and rapid diffusion under certain temperature.Then defects come into being because of galvanic effect during the process of post-etch wet clean with solvent.This defect can be eliminated by controlling temperature of PR strip process and water percentage of solven...