An etching method for an IC is provided. The etching method includes retrieving processing data including a pattern-density and at least one etching parameter of an etching process for a semiconductor device; determining end point time by consulting a table which records historical information of a plurality of PDs, the etching parameter and the EP time; compensating for the PD and the EP time by adjusting the etching parameter to perform the etching process; and performing the etching process on another semiconductor device based on the adjusted etching parameter, the PD and the EP time to manufacture the IC.