Semiconductor device with braded silicon nitride
AssigneeSemiconductor Energy Laboratory Co., Ltd.
InventorSatoshi Teramoto
Life of this patent
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Abstract
A gate insulating film covering active layers of a insulated gate field effect semiconductor device utilizing a thin film silicon semiconductor comprises a thin film having the chemical formula SiO.sub.x N.sub.y. By making the concentration of N (nitrogen) high at the interface between the gate insulating film and the gate electrodes, it is possible to prevent the material composing the gate electrodes from being diffused in the gate insulating film. By making the concentration of N (nitrogen) high at the interface between the gate insulating film and the active layers, it is possible to prevent hydrogen ions and other ions from diffusing into the gate insulating film from the active layer.
Claims18
An insulated gate field effect semiconductor device wherein a gate insulating film comprises a material represented as SiO.sub.x N.sub.y, and a distribution of N is varied in a thickness direction thereof so that a composition ratio of N at an interface between the gate insulating film and a gate electrode is higher than a composition ratio of N in a bulk portion of said gate insulating film.
An insulated gate field effect semiconductor device wherein a gate insulating film comprises a material represented as SiO.sub.x N.sub.y added with chlorine, and a distribution of N is varied in a thickness direction thereof.
A semiconductor device wherein a gate insulating film is constituted by a thin film represented as SiO.sub.x N.sub.y, and a composition ratio of N varies in a thickness direction of said gate insulating film and is higher at an interface between said gate insulating layer and a gate electrode and at an interface between said gate insulating film and an active layer.
An insulated gate field effect semiconductor device wherein a gate insulating film comprises a material represented as SiO.sub.x N.sub.y, and a distribution of N is varied in a thickness direction thereof, wherein a metal element for promoting crystallization of silicon is included in an active layer of said device, said metal element selected from the group consisting of Ni, Fe, Co, Ru, Pd, Os, Ir, Pt, Cu, Ag, and Au.
Dependencies are inferred from the claim text.