Semiconductor storage device and manufacturing method thereof

Abstract

A non-volatile semiconductor storage device having a high-dielectric-constant insulator and a manufacturing method thereof suitable for miniaturization are disclosed. According to one aspect of the present invention, it is provided a semiconductor storage device comprising a semiconductor substrate, a plurality of first conductor layers formed on the semiconductor substrate through a first insulator, an isolation formed between the plurality of first conductor layers, a silicon oxide film formed on the first conductor layer, a high-dielectric-constant insulator formed on the silicon oxide film and the isolation and being diffused silicon and oxygen at least in a surface thereof contacting with the silicon oxide film, and a second conductor film formed above the high-dielectric-constant insulator.

1 . A semiconductor storage device comprising: 
 a semiconductor substrate;    a plurality of first conductor layers formed on the semiconductor substrate through a first insulator;    an isolation formed between the plurality of first conductor layers;    a silicon oxide film formed on the first conductor layer;    a high-dielectric-constant insulator formed on the silicon oxide film and the isolation and being diffused silicon and oxygen at least in a surface thereof contacting with the silicon oxide film; and    a second conductor film formed above the high-dielectric-constant insulator.    
   
   
       2 . The semiconductor storage device according to  claim 1 , wherein the silicon oxide film has a film thickness of 4 nm or less.  
   
   
       3 . The semiconductor storage device according to  claim 1 , wherein a relative dielectric constant of the second insulator is 5 or greater.  
   
   
       4 . The semiconductor storage device according to  claim 3 , wherein the second insulator is a laminated film consisting of a plurality of insulators including an insulator whose relative dielectric constant is 5 or greater.  
   
   
       5 . The semiconductor storage device according to  claim 1 , wherein the second insulator contains at least aluminum or hafnium.  
   
   
       6 . The semiconductor storage device according to  claim 1 , wherein the second insulator contains at least an oxide or a nitride of aluminum, hafnium or zirconium.  
   
   
       7 . A manufacturing method of a semiconductor storage device, comprising: 
 depositing a first conductor layer on a semiconductor substrate through a first insulator;    patterning the first conductor layer, the first insulator and the semiconductor substrate to form an isolation extending in a first direction;    forming a silicon oxide film on the first conductor layer;    depositing a high-dielectric-constant insulator on the silicon oxide film;    depositing a second conductor film on the high-dielectric-constant insulator;    recovering defects in the high-dielectric-constant insulator by decomposing the silicon oxide film and supplying oxygen and/or silicon to the insulator by a heat treatment; and    patterning the second conductor layer and the high-dielectric-constant insulator to be extended in a second direction orthogonal to the first direction to form a memory cell.    
   
   
       8 . The manufacturing method of a semiconductor storage device according to  claim 7 , wherein the silicon oxide film has a film thickness of 1.5 nm to 4 nm.  
   
   
       9 . The manufacturing method of a semiconductor storage device according to  claim 7 , wherein a relative dielectric constant of the second insulator is 5 or greater.  
   
   
       10 . The manufacturing method of a semiconductor storage device according to  claim 9 , wherein the second insulator is a laminated film consisting of a plurality of insulators including an insulator whose relative dielectric constant is 5 or greater.  
   
   
       11 . The manufacturing method of a semiconductor storage device according to  claim 7 , wherein the heat treatment for the recovering is performed at a temperature of 500° C. to 1200° C.  
   
   
       12 . The manufacturing method of a semiconductor storage device according to  claim 7 , wherein the recovering is carried out between the depositing the high-dielectric-constant insulator and the depositing the second conductor layer.  
   
   
       13 . The manufacturing method of a semiconductor storage device according to  claim 7 , wherein the silicon oxide film is completely decomposed during the recovering.  
   
   
       14 . The manufacturing method of a semiconductor storage device according to  claim 13 , wherein the silicon oxide film has a film thickness of 1.5 nm to 4 nm.  
   
   
       15 . The manufacturing method of a semiconductor storage device according to  claim 13 , wherein a relative dielectric constant of the second insulator is 5 or greater.  
   
   
       16 . The manufacturing method of a semiconductor storage device according to  claim 15 , wherein the second insulator is a laminated film consisting of a plurality of insulators including an insulator whose relative dielectric constant is 5 or greater.  
   
   
       17 . The manufacturing method of a semiconductor storage device according to  claim 13 , wherein the second insulator contains at least aluminum or hafnium.  
   
   
       18 . The manufacturing method of a semiconductor storage device according to  claim 17 , wherein the second insulator contains at least an oxide or a nitride of aluminum, hafnium or zirconium.  
   
   
       19 . The manufacturing method of a semiconductor storage device according to  claim 13 , wherein the heat treatment for the recovering is performed at a temperature of 500° C. to 1200° C.  
   
   
       20 . The manufacturing method of a semiconductor storage device according to  claim 13 , wherein the recovering is carried out between the depositing the high-dielectric-constant insulator and the depositing the second conductor layer.