Patent ID: 7855134
Filing Date: 2010-12-21
Classification: H01L

Abstract:
1. A method of manufacturing a semiconductor device comprising a first conductivity type semiconductor element and a second conductivity type semiconductor element different from each other in conductivity type and aligned with each other, comprising the steps of: forming, in a semiconductor substrate, an element isolation film for isolating a first conductivity type element region in which the first conductivity type semiconductor element is to be formed from a second conductivity type element region in which the second conductivity type semiconductor element is to be formed; forming a first metal film over the surface of a gate insulating film placed over the main surface of the semiconductor substrate; forming a first cap layer containing a material different from that of the first metal film, over the upper surface of the first metal film formed in the first conductivity type element region; carrying out first heat treatment to cause a reaction between the first cap layer and the first metal film in the first conductivity type element region; forming a dual gate electrode structure different in composition between the first conductivity type element region and the second conductivity type element region, and wherein the first metal film contains any of first materials containing at least one element selected from the group comprised of titanium (Ti), tantalum (Ta), hafnium (Hf), nitrides of the first materials, carbides of the first materials, silicides of the first materials, nitride silicides of the first materials, and carbonitrides of the first materials, the first cap layer contains any of second materials containing at least one element selected from the group comprised of hafnium (Hf), tantalum (Ta), lanthanum (La), magnesium (Mg), ytterbium (Yb), oxides of the second materials, nitrides of the second materials, carbides of the second materials, silicides of the second materials, nitride silicides of the second materials, and carbonitrides of the second materials.