Semiconductor device and its manufacturing method

Abstract

In a fabrication method of a semiconductor device including a plurality of silicon-based transistors or capacitors, there exist hydrogen at least in a part of a silicon surface in advance, and the hydrogen is removed by exposing the silicon surface to a first inert gas plasma. Thereafter, plasma is generated by a mixed gas of a second inert gas and one or more gaseous molecules, and a silicon compound layer containing at least a part of the elements constituting the gaseous molecules is formed on the surface of the silicon gas.

1 - 4 . (canceled)  
   
   
       5 . A fabrication method of a semiconductor device on a silicon surface, comprising the steps of: 
 exposing said silicon surface to a first plasma of a first inert gas so as to remove hydrogen existing on at least a part of said silicon surface in advance; and    generating a second plasma of a mixed gas of a second inert gas and one or a plurality of kinds of gaseous molecules, and forming, on said silicon surface, a silicon compound layer containing at least a part of elements constituting the gaseous molecules under said second plasma.    
   
   
       6 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein, prior to the hydrogen removing step, the silicon surface is treated by a medium including hydrogen.  
   
   
       7 . The fabrication method of a semiconductor device as claimed in  claim 6 , wherein the medium is a hydrogenated water.  
   
   
       8 . The fabrication method of a semiconductor device as claimed in  claim 6 , wherein the medium is a diluted hydrofluoric acid.  
   
   
       9 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein the silicon surface is a single-crystal silicon surface.  
   
   
       10 . The fabrication method of a semiconductor device as claimed in  claim 9 , wherein the silicon surface is a (100)-oriented surface.  
   
   
       11 . The fabrication method of a semiconductor device as claimed in  claim 9 , wherein the silicon surface is a (111)-oriented surface.  
   
   
       12 . The fabrication method of a semiconductor device as claimed in  claim 9 , wherein the silicon surface includes a plurality of different crystal faces.  
   
   
       13 . The fabrication method of a semiconductor device as claimed in  claim 12 , wherein the plurality of different crystal faces define a device isolation trench.  
   
   
       14 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein the silicon surface is a polysilicon surface.  
   
   
       15 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein the silicon surface is an amorphous silicon surface.  
   
   
       16 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein each of the first and second inert gases is at least one kind of gas selected from a group consisting of an argon (Ar) gas, a krypton (Kr) gas, and a xenon (Xe) gas.  
   
   
       17 . The fabrication method of a semiconductor device as claimed in  claim 16 , wherein the first inert gas is identical with the second inert gas.  
   
   
       18 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein the second inert gas is a krypton (Kr) gas, the gaseous molecules are oxygen ( 02 ) molecules, and a silicon oxide film is formed as the silicon compound layer.  
   
   
       19 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein the second inert gas is an argon (Ar) gas, a krypton (Kr) gas, or a mixed gas of argon and krypton, the gaseous molecules are ammonia (NH 3 ) molecules or nitrogen (N 2 ) molecules and hydrogen (H 2 ) molecules, and a silicon nitride film is formed as the silicon compound layer.  
   
   
       20 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein the second inert gas is an argon (Ar) gas, a krypton (Kr) gas, or a mixed gas of argon and krypton, the gaseous molecules are oxygen (O2) molecules and ammonia (NH3) molecules, or oxygen (O2) molecules, nitride (N2) molecules, and hydrogen (H2) molecules, and a silicon oxynitride film is formed as the silicon compound layer.  
   
   
       21 . The fabrication method of a semiconductor device as claimed in  claim 5 , wherein the first plasma and the second plasma are excited by microwave.  
   
   
       22 . A fabrication method of a semiconductor memory device that includes, on a common substrate, a transistor having a polysilicon film formed on a silicon surface via a first insulation film and a capacitor including a second insulation film formed on a polysilicon surface, comprising the steps of: 
 exposing the silicon surface to a first plasma of a first inert gas so as to remove hydrogen existing on at least a part of the silicon surface in advance; and    generating a second plasma of a mixed gas of a second inert gas and one or a plurality of kinds of gaseous molecules, and forming, on the silicon surface, a silicon compound layer containing at least a part of elements constituting the gaseous molecules as the first insulation film under said second plasma.    
   
   
       23 . The fabrication method of a semiconductor device as claimed in  claim 22 , further comprising the steps of: 
 exposing the polysilicon surface to a third plasma of a third inert gas so as to remove hydrogen existing on at least a part of the silicon surface in advance; and    forming a fourth plasma of a mixed gas of a fourth inert gas and one or a plurality of kinds of gaseous molecules, and forming, on the polysilicon surface, a silicon compound layer containing at least a part of elements constituting the gaseous molecules as the second insulation film under said fourth plasma.    
   
   
       24 . The fabrication method of a semiconductor device as claimed in  claim 23 , wherein the first and third inert gases are at least one kind of gas selected from a group consisting of Ar, Kr, and Xe.  
   
   
       25 . The fabrication method of a semiconductor device as claimed in  claim 23 , wherein the second and fourth inert gases are Kr, and the first and second insulation films are formed by a silicon oxide film.  
   
   
       26 . The fabrication method of a semiconductor device as claimed in  claim 23 , wherein the second and fourth inert gases are Ar or Kr, and the first and second insulation films are formed by a nitride film or an oxynitride film.  
   
   
       27 . The fabrication method of a semiconductor device as claimed in any of claims  22 - 26 , wherein the first and second plasmas are excited by microwave.  
   
   
       28 . A fabrication method of a semiconductor device having a polysilicon layer or amorphous silicon layer on a substrate as an active layer, comprising the steps of: 
 forming, on said substrate, a silicon layer of said polysilicon layer or amorphous layer;    exposing a surface of said silicon layer to a plasma of a first inert gas so as to remove hydrogen existing on at least a part of said surface of said silicon layer; and    generating a plasma of a mixed gas of a second inert gas and one or a plurality of kinds of gaseous molecules, and forming, on said surface of said silicon layer, a silicon compound layer including at least a part of elements constituting said gaseous molecules.    
   
   
       29 . The fabrication method of a semiconductor device as claimed in  claim 28 , wherein the first inert gas is at least one kind of gas selected form a group consisting of Ar, Kr, and Xe.  
   
   
       30 . The fabrication method of a semiconductor device as claimed in  claim 28 , wherein the second inert gas is Kr, and the silicon compound layer is a silicon oxide film.  
   
   
       31 . The fabrication method of a semiconductor device as claimed in  claim 28 , wherein the second inert gas is Ar or Kr, and the silicon compound layer is a nitride film or an oxynitride film.  
   
   
       32 . The fabrication method of a semiconductor device as claimed in  claim 28 , wherein the first and second plasmas are excited by microwave.