Semiconductor device and process for producing the same

Abstract

With regard to a semiconductor apparatus thermally stable in a post process and suitable for fabricating a gate insulator having a laminated structure with various high permittivity oxides and a process of producing the same, in order to achieve high function formation of a gate insulator 8 , a silicon nitride film specific inductive capacity of which is approximately twice as much as that of silicon oxide and which is thermally stable and is not provided with Si—H bond, is used as at least a portion of the gate insulator 8 . Further, an effective thickness of a gate insulator forming a multilayered structure insulator laminated with a metal oxide having high dielectric constant, in conversion to silicon oxide, can be thinned to less than 3 nm while restraining leakage current.

What is claimed is:  
     
         1 . A semiconductor device which is a semiconductor device constituting an active layer by a single crystal or polycrystal silicon semiconductor and having a gate electrode on said active layer by interposing a gate insulator, wherein said gate insulator is formed by a silicon nitride film which does not include a chemical bond of hydrogen atoms and silicon atoms.  
     
     
         2 . A semiconductor device which is a semiconductor device constituting an active layer by a single crystal or polycrystal silicon semiconductor and having a gate electrode on said active layer by interposing a gate insulator, wherein said gate insulating film is constituted by a multilayered structure film including at least one layer of a silicon nitride film which does not include a chemical bond of hydrogen atoms and silicon atoms.  
     
     
         3 . A semiconductor device which is a semiconductor device constituting an active layer by a single crystal or polycrystal silicon semiconductor and having a gate electrode on said active layer by interposing a gate insulator, wherein said gate insulator is constituted by a multilayered structure film including at least one layer of a silicon nitride film which does not include a chemical bond of hydrogen atoms and silicon atoms and at least one layer of a ferroelectric thin film.  
     
     
         4 . The semiconductor device according to  claim 2  or  3 , wherein in the multilayered structure film constituting said gate insulator, a film other than said silicon nitride film is constituted by a thin film comprising a polycrystal or amorphous oxide.  
     
     
         5 . A semiconductor device which is a semiconductor device constituting an active layer by a single crystal or polycrystal silicon semiconductor and having a gate electrode on said active layer by interposing a gate insulator, wherein said gate insulator is constituted by a silicon oxi-nitride film which includes a chemical bond of oxygen atoms and silicon atoms and does not include a chemical bond of hydrogen atoms and silicon atoms.  
     
     
         6 . A semiconductor device which is a semiconductor device constituting an active layer by a single crystal or polycrystal silicon semiconductor and having a gate electrode on said active layer by interposing a gate insulator, wherein said gate insulator is constituted by a multilayered structure film including at least one layer of a silicon oxi-nitride film which includes a chemical bond of oxygen atoms and silicon atoms and does not include a chemical bond of hydrogen atoms and silicon atoms.  
     
     
         7 . A semiconductor device which is a semiconductor device constituting an active layer by a single crystal or polycrystal silicon semiconductor and having a gate electrode on said active layer by interposing a gate insulator, wherein said gate insulator is constituted by a multilayered structure film including at least one layer of a silicon oxi-nitride film which includes a chemical bond of oxygen atoms and silicon atoms and does not include a chemical bond of hydrogen atoms and silicon atoms and at least one layer of a ferroelectric film.  
     
     
         8 . The semiconductor apparatus according to  claim 6  or  7 , wherein in the multilayered structure film constituting said gate insulator, a film other than said silicon oxi-nitride film is formed by a thin film comprising a metal oxide.  
     
     
         9 . A process of producing a semiconductor device which is a process of producing a semiconductor device having a step of constituting an active layer by a single crystal or polycrystal silicon semiconductor substrate and forming a gate electrode on said active layer by interposing a gate insulator, wherein by using a nitrogen radical in a nitrogen plasma as a major active species of nitridation, said substrate is nitrided and said gate insulator is formed.