Semiconductor device and method for manufacturing the same

Abstract

It is made possible to provide a method for manufacturing a semiconductor device that has a high-quality insulating film in which defects are not easily formed, and experiences less leakage current. A method for manufacturing a semiconductor device, includes: forming an amorphous silicon layer on an insulating layer; introducing oxygen into the amorphous silicon layer; and forming a silicon oxynitride layer by nitriding the amorphous silicon layer having oxygen introduced thereinto.

1 .- 15 . (canceled) 
     
     
         16 . A semiconductor device, comprising:
 a silicon substrate;   a tunnel insulating film formed on the silicon substrate, the tunnel insulating film including silicon, oxygen, and nitrogen;   a floating gate electrode formed on the tunnel insulating film;   an insulating film formed on the floating gate electrode; and   a control electrode formed on the insulating film,   wherein a nitrogen distribution is formed across the tunnel insulating film and the floating gate electrode and the nitrogen distribution has a first peak and a second peak, the first peak is located closer to the silicon substrate than the second peak, a nitrogen concentration at a first interface between the silicon substrate and the tunnel insulating film is lower than a nitrogen concentration at a second interface between the tunnel insulating film and the floating gate electrode.   
     
     
         17 . The device according to  claim 16 , wherein the nitrogen concentration at the second interface is lower than a nitrogen concentration at the first peak. 
     
     
         18 . The device according to  claim 16 , wherein the nitrogen concentration at the second interface is lower than a nitrogen concentration at the second peak. 
     
     
         19 . The device according to  claim 16 , wherein a nitrogen concentration at the second peak is lower than a nitrogen concentration at the first peak. 
     
     
         20 . The device according to  claim 16 , wherein the nitrogen concentration at the second interface is lower than a nitrogen concentration at the second peak, and the nitrogen concentration at the second peak is lower than a nitrogen concentration at the first peak. 
     
     
         21 . The device according to  claim 16 , wherein a nitrogen concentration of the first peak is in range of 20 atomic % to 47 atomic %. 
     
     
         22 . The device according to  claim 16 , wherein the first peak has a substrate-side tail included in the tunnel insulating film. 
     
     
         23 . The device according to  claim 16 , wherein the nitrogen distribution has a continuous region where nitrogen concentration is 20 atomic % or higher, and the continuous region has a physical film thickness of 1 nm or more. 
     
     
         24 . The device according to  claim 23 , wherein the continuous region is in a region 5 nm or less from the second interface. 
     
     
         25 . The device according to  claim 23 , wherein the first peak is located in the continuous region, and the second peak is located out of the continuous region. 
     
     
         26 . The device according to  claim 16 , wherein a distance between the first peak and the first interface is longer than a distance between the second peak and the second interface. 
     
     
         27 . The device according to  claim 16 , wherein the first peak has a substrate-side tail, the second peak has a control electrode-side tail, and the substrate-side tail is steeper than the control electrode-side tail of the second peak. 
     
     
         28 . The device according to  claim 16 , wherein the insulating film is a laminated film including a silicon oxide layer and an alumina layer. 
     
     
         29 . The device according to  claim 16 , wherein the insulating film is a laminated film, the control electrode is a laminated film, and the control electrode includes tungsten. 
     
     
         30 . The device according to  claim 16 , further comprising a mask material formed on the control electrode, and a silicon oxide film covering a stack including the mask material, the control electrode, the insulating film, the floating gate electrode, and the tunnel insulating film. 
     
     
         31 . The device according to  claim 16 , further comprising:
 memory cells arranged in a matrix form, each of the memory cells including the tunnel insulating film, the floating gate electrode, the insulating film, and the control electrode.   
     
     
         32 . The device according to  claim 16 , further comprising:
 memory cells arranged in a matrix form;   wherein the insulating film includes a first layer above the floating gate electrode and a second layer above the first layer, the second layer extends in a first direction over the memory cells, and the first layer includes portion that are separately formed for each respective one of the memory cells in the first direction.   
     
     
         33 . A semiconductor device comprising:
 a silicon region;   a tunnel insulating film formed on the silicon region, the tunnel insulating film including silicon, oxygen, and nitrogen;   a charge storage film formed on the tunnel insulating film;   an insulating film formed on the charge storage film; and   a control electrode formed on the insulating film,   wherein a nitrogen distribution is formed across the tunnel insulating film and the charge storage film and the nitrogen distribution has a first peak and a second peak, the first peak is located closer to the silicon region than the second peak, a nitrogen concentration at a first interface between the silicon region and the tunnel insulating film is lower than a nitrogen concentration at a second interface between the tunnel insulating film and the charge storage film.   
     
     
         34 . The device according to  claim 33 , wherein the nitrogen concentration at the second interface is lower than a nitrogen concentration at the first peak. 
     
     
         35 . The device according to  claim 33 , wherein the nitrogen concentration at the second interface is lower than a nitrogen concentration at the second peak. 
     
     
         36 . The device according to  claim 33 , wherein a nitrogen concentration at the second peak is lower than a nitrogen concentration at the first peak. 
     
     
         37 . The device according to  claim 33 , wherein the nitrogen concentration at the second interface is lower than a nitrogen concentration at the second peak, and the nitrogen concentration at the second peak is lower than a nitrogen concentration at the first peak. 
     
     
         38 . The device according to  claim 33 , wherein a nitrogen concentration of the first peak is in range of 20 atomic % to 47 atomic %. 
     
     
         39 . The device according to  claim 33 , wherein the first peak has a silicon region-side tail included in the tunnel insulating film. 
     
     
         40 . The device according to  claim 33 , wherein the nitrogen distribution has a continuous region where nitrogen concentration is 20 atomic % or higher, and the continuous region has a physical film thickness of 1 nm or more. 
     
     
         41 . The device according to  claim 40 , wherein the continuous region is in a region 5 nm or less from the second interface. 
     
     
         42 . The device according to  claim 40 , wherein the first peak is located in the continuous region, and the second peak is located out of the continuous region. 
     
     
         43 . The device according to  claim 33 , wherein a distance between the first peak and the first interface is longer than a distance between the second peak and the second interface. 
     
     
         44 . The device according to  claim 33 , wherein the first peak has a silicon region-side tail, the second peak has a control electrode-side tail, and the substrate-side tail is steeper than the control electrode-side tail of the second peak. 
     
     
         45 . The device according to  claim 33 , wherein the insulating film is a laminated film including a silicon oxide layer and an alumina layer. 
     
     
         46 . The device according to  claim 33 , wherein the insulating film is a laminated film, the control electrode is a laminated film, and the control electrode includes tungsten. 
     
     
         47 . The device according to  claim 33 , further comprising:
 memory cells arranged in a first direction;   wherein the insulating film includes a first layer above the charge storage film and a second layer above the first layer, the second layer extends in the first direction over the memory cells, and the first layer includes portions that are separately formed for each respective one of the memory cells in the first direction.