METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE WITH DUAL GATES

摘要

A method for fabricating a semiconductor device having a dual gate is provided to fabricate a semiconductor device having a dual gate with an excellent operating speed by forming a first upper gate insulation layer including a hafnium oxide layer and an aluminum oxide layer in a PMOS region and by forming a second upper gate insulation layer including a hafnium oxide layer in an NMOS region. A silicon oxide layer is formed as a lower gate insulation layer on a semiconductor substrate(100) divided into a PMOS region(130) and an NMOS region(132). A hafnium aluminum nitride layer is formed on the silicon oxide layer. A heat treatment is performed on the hafnium aluminum nitride layer in an atmosphere of oxide gas including oxygen to form a dual layer composed of a hafnium oxide layer and an aluminum oxide layer. The aluminum oxide layer existing in the NMOS region is selectively removed so that a multiple layer of a first upper gate insulation layer including the hafnium oxide layer and the aluminum oxide layer is formed in the PMOS region and a single layer of a second upper gate insulation layer including a hafnium oxide layer is formed in the NMOS region. A first gate is formed on the first upper gate insulation layer, and a second gate is formed on the second upper gate insulation layer. The hafnium aluminum nitride layer can be formed by a PVD method or a CVD method.