Method for manufacturing a semiconductor integrated circuit device

Abstract

The resist film after high-concentration ion implantation has a hard modified layer on the surface thereof, and is difficult to remove in the temperature region as low as about 150 degrees centigrade. This is because the etching rate of the modified layer sharply decreases with a decrease in temperature. The temperature is increased up to about 250 degrees centigrade to perform an ashing treatment in vacuum in order to increase the etching rate of the modified layer. Then, there occurs a popping phenomenon that the inside resist solvent swells and breaks. The residues scattered thereby of the modified layer and the like seize the wafer surface, and also become difficult to remove even in the subsequent cleaning. According to the present application, in order to remove the resist hardened by ion implantation and the like, the to-be-treated wafer is baked under atmospheric pressure, and then, is subjected to a plasma ashing treatment within the temperature region as high as around 300 degrees centigrade under an oxygen gas atmosphere substantially including an oxygen gas.

Dependencies are inferred from the claim text.