Semiconductor device with metal nitride barrier layer between gate dielectric and silicided, metallic gate electrodes
View Patent ↗A method for manufacturing a semiconductor device includes: sequentially depositing a gate insulating film 104 composed of a high dielectric constant film containing one or more metallic element(s) selected from a group consisting of Hf, Zr, Al, La and Ta, a barrier film 106 composed of one or more metal nitride selected from a group consisting of TiN, TaN and WN, a metallic film 108 and a polycrystalline silicon film 110 on the semiconductor substrate (p-type semiconductor substrate 102 a ) to form a multiple-layered film; and silicidizing a lower portion of the polycrystalline silicon film 110 to form a lower layer (forming a first silicide layer 110 a ) by conducting a heat treatment of the multiple-layered film to diffuse the metal of the metallic film 108 into the polycrystalline silicon film 110.
1. A semiconductor device, comprising:
a semiconductor substrate; and
a gate electrode formed on said semiconductor substrate,
wherein said gate electrode includes a multiple-layered structure composed of:
a gate insulating film composed of a high dielectric constant film containing one or more metallic elements selected from a group consisting of hafnium (Hf), zirconium (Zr), aluminum (Al), lanthanum (La) and tantalum (Ta);
a barrier film composed of one or more metal nitrides selected from a group consisting of titanium nitride (TiN), tantalum nitride (TaN) and tungsten nitride (WN); and
a polycrystalline silicon film having a silicidized lower layer.
2. The semiconductor device according to claim 1 , wherein
a portion in said polycrystalline silicon film around said metal nitride film include M x Si (where M is a metallic element selected from Ni, Co, W and Ti, and x is a number of not less than 1).
3. The semiconductor device according to claim 2 , wherein an upper layer of said polycrystalline silicon film is a silicide layer.
4. The semiconductor device according to claim 3 , wherein different type of metals are used for silicidizing said upper layer and said lower layer of said polycrystalline silicon film, respectively.
5. The semiconductor device according to claim 1 , wherein an upper layer of said polycrystalline silicon film is a silicide layer.
6. The semiconductor device according to claim 5 , wherein different type of metals are used of silicidizing said upper layer and said lower layer of said polycrystalline silicon film, respectively.
7. The semiconductor device according to claim 1 , further comprising:
a second semiconductor substrate isolated from said semiconductor substrate, in which a polarity of said second semiconductor substrate is opposite to a polarity of said semiconductor substrate; and
a second gate electrode formed on said second semiconductor substrate,
wherein said second gate electrode includes a multiple-layered structure composed of:
a second gate insulating film composed of a high dielectric constant film containing one or more metallic elements selected from a group consisting of hafnium (Hf), zirconium (Zr), aluminum (Al), lanthanum (La) and tantalum (Ta);
a second barrier film composed of one or more metal nitrides selected from a group consisting of titanium nitride (TiN), tantalum nitride (TaN), and tungsten nitride (WN); and
a second polycrystalline silicon film having a silicidized lower layer.