Abstract: A semiconductor device 100 comprises a silicon substrate 102, an N-type MOSFET 118 including a high concentration-high dielectric constant film 108b formed on the silicon substrate 102 and a polycrystalline silicon film 114, and a P-type MOSFET 120 including a low concentration-high dielectric constant film 108a and a polycrystalline silicon film 114 formed on the semiconductor substrate 102 to be juxtaposed to the N-type MOSFET 118. The low concentration-high dielectric constant film 108a and the high concentration-high dielectric constant film 108b are composed of a material containing one or more element (s) selected from a group consisting of Hf and Zr. The concentration of the above-described metallic element contained in the low concentration-high dielectric constant film 108a is lower than that contained in the high concentration-high dielectric constant film 108b.

Abstract: The semiconductor device 100 comprises a silicon substrate 102, an N-type MOSFET 118 including a first high dielectric constant film 111 and a polycrystalline silicon film 114 formed on the silicon substrate 102, and a P-type MOSFET 120 including a second high dielectric constant film 112 and a polycrystalline silicon film 114 juxtaposed to N-type MOSFET 118 on the silicon substrate 102. The second high dielectric constant film 112 is formed to have the film thickness thinner than the film thickness of the first high dielectric constant film 111. The first high dielectric constant film 111 and the second high dielectric constant film 112 contains one or more element(s) selected from a group consisting of Hf and Zr.

Abstract: In P-channel MOS transistor comprising a gate insulating film composed of a high dielectric constant material and the gate electrode composed of polycrystalline silicon, a technology for preventing Fermi level pinning and providing a stable reduction of the threshold voltage is provided. The MOS transistor functions as a buried channel transistor formed by implanting In as a P-type impurity into the channel region. In addition, the gate electrode is composed of the polycrystalline silicon film, which is doped with N-type impurity. Thus, the gate depletion caused by Fermi level pinning can be effectively inhibited. Therefore the depletion in the gate electrode can be avoided and the threshold voltage can be stably diminished. In this case, the threshold voltage is stably reduced since electric charge is induced by applying a constant voltage to the gate electrode.

Abstract: In a semiconductor device including a semiconductor substrate (10; 56), at least one electrode structure (34, 36; 72, 74) is provided on a surface of the semiconductor substrate. The electrode structure is constructed as a multi-layered electrode structure including an insulating layer (34A, 36A; 72A, 74A) formed on the surface of the semiconductor substrate and composed of a dielectric material exhibiting a dielectric constant larger than that of silicon dioxide, a lower electrode layer (34B, 36B; 72B, 74B) formed on the insulating layer and composed of polycrystalline silicon, and an upper electrode layer (34C, 36C; 72D, 74D) formed on the lower electrode layer and composed of polycrystalline silicon. The lower electrode layer features an average grain size of polycrystalline silicon which is larger than that of polycrystalline silicon of the upper electrode layer.

Abstract: A technology of restraining junction leakage in a semiconductor device is to be provided. There is provided a semiconductor device provided with a semiconductor substrate, a gate electrode 9 formed on the semiconductor substrate, and a source/drain region formed beside the gate electrode, wherein the source/drain region 4 comprises a first impurity diffusion region including a first P-type impurity and located in the proximity of a surface of the semiconductor substrate, and a second P-type impurity diffusion region located below the first impurity diffusion region and including a second P-type impurity having a smaller diffusion coefficient in the semiconductor substrate than the first P-type impurity.