Fujitsu Semiconductor Limited

Fujitsu Corporation

Fujitsu Microelectronics Limited

Tsunehisa Sakoda

Kazuto Ikeda

Hiroshi Nomura

Takashi Saiki

Masaomi Yamaguchi

Hiroshi Minakata

Yoshihiro Sugita

Four regions (a narrow NMOS region, a wide NMOS region, a wide PMOS region, and a narrow PMOS region) are defined on a semiconductor substrate. Then, after a gate insulating film and a polysilicon film are sequentially formed on the semiconductor substrate, n-type impurities are introduced into the polysilicon film in the wide NMOS region. Next, by patterning the polysilicon film, gate electrodes are formed in the four regions. Then, n-type impurities are introduced into the gate electrodes in the narrow NMOS region and the wide NMOS region. As a result, an impurity concentration of the gate electrode in the narrow NMOS region becomes lower than that of the gate electrode in the wide NMOS region.

Method of fabricating field effect transistors with different gate widths

A semiconductor device capable of suppressing a threshold shift and a manufacturing method of the semiconductor device. On a high dielectric constant insulating film, a diffusion barrier film for preventing the diffusion of metal elements from the high dielectric constant insulating film to an upper layer is formed. Therefore, the diffusion of the metal elements from the high dielectric constant insulating film to the upper layer can be prevented. As a result, a reaction and bonding between the metal elements and a Si element in a gate electrode can be suppressed near a boundary between an insulating film and the gate electrode.

Semiconductor device and manufacturing method thereof

Field effect transistors with different gate widths

A permeation preventing film of a silicon nitride filmis inserted between a silicon substrateand a High-k gate insulation filmto thereby prevent the High-k gate insulation filmfrom being deprived of oxygen, while oxygen anneal is performed after a gate electrode layerhas been formed to thereby supplement oxygen. The silicon nitride filmwhich is the permeation preventing film, becomes a silicon oxide nitride filmwithout changing the film thickness, whereby characteristics deterioration of the High-k gate insulation filmdue to the oxygen loss can be prevented without lowering the performance of the transistor. The semiconductor device having the gate insulation film formed of even a high dielectric constant material can be free from the shift of the threshold voltage.

Semiconductor device and method for fabricating the same

A semiconductor device manufacture method has the steps of: (a) forming an interface layer of SiO or SiON on the surface of an active region of a silicon substrate; (b) forming a high dielectric constant gate insulating film such as HfSiON having a dielectric constant higher than that of silicon oxide, above the interface layer; (c) forming a gate electrode of polysilicon above the high dielectric constant gate insulating film; (d) passivating the substrate surface at least before or after the high dielectric constant gate insulating film is formed; (e) forming an insulated gate electrode structure by patterning at least the gate electrode and the high dielectric constant gate insulating film; and (f) forming source/drain regions in the active region on both sides of the insulated gate electrode structure. The semiconductor device has the high dielectric constant insulating film having a dielectric constant higher than that of silicon oxide.

Growing community of inventors

Kawasaki, Japan

Tsunehisa Sakoda