Semiconductor Device and Method of Fabricating the same

Abstract

The invention relates to semiconductor devices and a method of fabricating the same. In accordance with a method of fabricating a semiconductor device according to an aspect of the invention, a tunnel insulating layer, a first conductive layer, a dielectric layer, a second conductive layer, and a gate electrode layer are sequentially stacked over a semiconductor substrate. The gate electrode layer, the second conductive layer, the dielectric layer, and the first conductive layer are patterned so that the first conductive layer partially remains to prevent the tunnel insulating layer from being exposed. Sidewalls of the gate electrode layer are etched. A first passivation layer is formed on the entire surface including the sidewalls of the gate electrode layer. At this time, a thickness of the first passivation layer formed on the sidewalls of the gate electrode layer is thicker than that of the first passivation layer formed in other areas. A cleaning process is performed to thereby remove byproducts occurring in the etch process. A gate pattern is formed by etching the first passivation layer, the first conductive layer, and the tunnel insulating layer.

1 . A semiconductor device, comprising:
 a gate pattern comprising a tunnel insulating layer, a conductive layer for a floating gate, a dielectric layer, a conductive layer for a control gate, and a gate electrode layer sequentially stacked over a semiconductor substrate, the gate electrode layer defining sidewalls;   a first passivation layer formed on the sidewalls of the gate electrode layer; and   a second passivation layer formed on the entire surface along a surface of the first passivation layer and the gate pattern,   wherein a critical dimension of the gate electrode layer is smaller than that of the conductive layer for the control gate.   
   
   
       2 . The semiconductor device of  claim 1 , wherein the first passivation layer is formed on the sidewalls of the gate electrode layer and on the same line as that of the sidewalls of the gate pattern. 
   
   
       3 . The semiconductor device of  claim 1 , wherein:
 the first passivation layer comprises a nitride layer, and   the second passivation layer comprises an oxide layer.   
   
   
       4 . The semiconductor device of  claim 1 , wherein the second passivation layer comprises a high-temperature oxide (HTO) layer, a low-pressure tetraethyl orthosilicate (LP-TEOS) layer, or an atomic layer depostion (ALD) oxide layer. 
   
   
       5 . A method of fabricating a semiconductor device, comprising:
 sequentially stacking a tunnel insulating layer, a first conductive layer, a dielectric layer, a second conductive layer, and a gate electrode layer over a semiconductor substrate, the gate electrode layer defining sidewalls;   patterning the gate electrode layer, the second conductive layer, the dielectric layer, and the first conductive layer, wherein the first conductive layer partially remains to prevent the tunnel insulating layer from being exposed;   etching the sidewalls of the gate electrode layer;   forming a first passivation layer on the entire surface including the sidewalls of the gate electrode layer, wherein the first passivation layer formed on the sidewalls of the gate electrode layer is thicker than the first passivation layer formed in other areas;   performing a cleaning process to remove byproducts resulting from the etch process of the gate electrode layer; and   forming a gate pattern by etching the first passivation layer, the first conductive layer, and the tunnel insulating layer.   
   
   
       6 . The method of  claim 5 , further comprising, after forming the gate pattern, oxidizing a part of the first passivation layer and sidewalls of the second conductive layer by performing an oxidization process, thus forming a second passivation layer. 
   
   
       7 . The method of  claim 6 , comprising forming the second passivation layer by oxidizing the first passivation layer formed on the sidewalls of the second conductive layer and the dielectric layer, and a part of the first passivation layer formed on the sidewalls of the gate conductive layer. 
   
   
       8 . The method of  claim 6 , comprising performing the oxidization process to oxidize 30% to 80% of the first passivation layer formed on the sidewalls of the gate conductive layer to form the second passivation layer. 
   
   
       9 . The method of  claim 5 , comprising in etching the sidewalls of the gate electrode layer, etching the sidewalls of the gate electrode layer by 1 nm to 10 nm. 
   
   
       10 . The method of  claim 5 , comprising etching the sidewalls of the gate electrode layer using a dry etch process or a wet etch process, wherein the wet etch process comprises using H 2 SO 4 , NH 4 OH, H 2 O, HF, HCl, or H 2 O 2 , either alone or in combination. 
   
   
       11 . The method of  claim 5 , wherein the first passivation layer comprises a nitride layer. 
   
   
       12 . The method of  claim 5 , comprising forming the first passivation layer to fill convex portions that have been generated in the process of etching the sidewalls of the gate conductive layer, so that a layer formed on the sidewalls of a conductive layer for a gate is thicker than a layer formed in the remaining areas. 
   
   
       13 . The method of  claim 5 , comprising forming the first passivation layer using SiH 4 , Si 2 H 6 , Si 2 HCl 2 , NH 3 , N 2 , Ar, He, or PH 3  gas in a pressure range of 0.05 Torr to 50 Torr. 
   
   
       14 . The method of  claim 5 , comprising forming the first passivation layer to a thickness of 1 nm to 15 nm. 
   
   
       15 . The method of  claim 6 , wherein the second passivation layer is formed to a thickness of 1 nm to 12 nm. 
   
   
       16 . The method of  claim 6 , comprising forming the second passivation layer using a radical oxidization process. 
   
   
       17 . The method of  claim 6 , further comprising forming a third passivation layer over the semiconductor substrate including the second passivation layer, wherein the third passivation layer comprises a high-temperature oxide (HTO) layer, a low-pressure tetraethyl orthosilicate (LP-TEOS) layer, or an atomic layer deposition (ALD) oxide layer. 
   
   
       18 . The method of  claim 5 , comprising performing the cleaning process using a wet cleaning process or a dry cleaning process in either case employing HF, NH 4 OH, or H 2 SO 4 , either alone or in combination. 
   
   
       19 . A method of fabricating a semiconductor device, comprising:
 sequentially stacking a tunnel insulating layer, a first conductive layer, a dielectric layer, a second conductive layer, and a gate electrode layer over a semiconductor substrate, the gate electrode layer defining sidewalls;   patterning the gate electrode layer and the second conductive layer, wherein the second conductive layer partially remains to prevent the dielectric layer from being exposed;   etching the sidewalls of the gate electrode layer;   forming a first passivation layer on the entire surface including the sidewalls of the gate electrode layer;   performing a cleaning process to thereby remove byproducts resulting from the etch process of the gate electrode layer; and   forming a gate pattern by etching the first passivation layer, the second conductive layer, and the dielectric layer, the first conductive layer, and the tunnel insulating layer.   
   
   
       20 . The method of  claim 19 , further comprising, after forming the gate pattern, forming a second passivation layer over the semiconductor substrate including the gate pattern. 
   
   
       21 . The method of  claim 19 , comprising in etching the sidewalls of the gate conductive layer, etching the sidewalls of the gate electrode layer by 1 nm to 13 nm. 
   
   
       22 . The method of  claim 19 , comprising etching the gate electrode layer using a dry or wet etch process, wherein the wet etch process is performed using H 2 SO 4 , NH 4 OH, H 2 O, HF, HCl, or H 2 O 2 , either alone or in combination. 
   
   
       23 . The method of  claim 19 , wherein the first passivation layer comprises a nitride layer or a dual layer of a nitride layer and an oxide layer. 
   
   
       24 . The method of  claim 19 , comprising forming the first passivation layer using SiH 4 , Si 2 H 6 , Si 2 HCl 2 , NH 3 , N 2 , Ar, He, or PH 3  gas and in a pressure range of 0.05 Torr to 50 Torr. 
   
   
       25 . The method of  claim 19 , further comprising forming a second passivation layer over the semiconductor substrate including the first passivation layer from a high-temperature oxide (HTO) layer, a low-pressure tetraethyl orthosilicate (LP-TEOS) layer, or an atomic layer deposition (ALD) oxide layer. 
   
   
       26 . The method of  claim 19 , comprising performing the cleaning process using a wet cleaning process or a dry cleaning process in either case employing HF, NH 4 OH, or H 2 SO 4 , either alone or in combination.