Method for reducing the contact resistance

A method for reducing the contact resistance using plasma process tries to solve the problem that the cleaning process could not remove both the residues and oxides on the etched surface effectively. A plasma treating process is performed after the cleaning process and before any following process. Herein, the plasma treating process uses the plasma(s) to physically and/or chemically react with the etched surface. For example, inert gas plasma is used to remove these residues and the oxides, and then hydrogen plasma is used to compensate the unsaturated bonds by inducing the ions bombardment of the inert gas plasma.