A method for removing hard masks on gates in a semiconductor manufacturing process is conducted as follows. First of all, a first gate and a second gate with hard masks are formed on a semiconductor substrate, wherein the second gate is larger than the first gate. The first gate and second gate could be associated with silicon-germanium (SiGe) source and drain regions to form p-type transistors. Next, a photoresist layer is deposited, and an opening of the photoresist layer is formed on the hard mask of the second gate. Then, the photoresist layer on the first and second gates is removed completely by etching back. Because there is no photoresist residue, the hard masks on the first and second gates can be removed completely afterwards.