Patent ID: 7989283

Claim:
A manufacturing method of a semiconductor device, the semiconductor device including a first MISFET of an n-channel type in a first region of a semiconductor substrate, and a second MISFET of a p-channel type in a second region of the semiconductor substrate, the manufacturing method comprising the steps of: (a) preparing the semiconductor substrate; (b) respectively forming a first high dielectric constant gate insulator containing hafnium, lanthanum, and oxygen as a principal component in the first region over the semiconductor substrate, and a second high dielectric constant gate insulator containing hafnium, aluminum, and oxygen as a principal component in the second region over the semiconductor substrate; (c) forming a metal film over the first high dielectric constant gate insulator in the first region, and the second high dielectric constant gate insulator in the second region; (d) forming a first metal gate electrode of the first MISFET in the first region, and a second metal gate electrode of the second MISFET in the second region by patterning the metal film by dry etching; and (e) after the step (d), removing a part of the first high dielectric constant gate insulator not covered with the first metal gate electrode in the first region, and a part of the second high dielectric constant gate insulator not covered with the second metal gate electrode in the second region by wet etching, wherein the step (e) comprises the steps of: (e1) applying a wet process to the semiconductor substrate with a first acid solution not containing hydrofluoric acid; (e2) applying another wet process to the semiconductor substrate with an alkaline solution; and (e3) after the steps (e1) and (e2), applying a further wet process to the semiconductor substrate with a second acid solution containing hydrofluoric acid.