Method for manufacturing a semiconductor device

Abstract

Over a semiconductor substrate, a gate insulating film including an interfacial layer, a HfON film, and a HfSiON film is formed. Then, over the HfSiON film, an Al-containing film and a mask layer are formed. Subsequently, the mask layer and the Al-containing film are selectively removed from an n-channel MISFET formation region. Then, a rare-earth-element-containing film is formed over the HfSiON film in the n-channel MISFET formation region and over the mask layer in a p-channel MISFET formation region. Heat treatment is performed to cause a reaction between each of the HfON film and the HfSiON film and the rare-earth-element-containing film in the n-channel MISFET formation region and cause a reaction between each of the HfON film and the HfSiON film and the Al-containing film in the p-channel MISFET formation region. Thereafter, the unreacted rare-earth-element-containing film and the mask layer are removed, and then metal gate electrodes are formed.

What is claimed is: 
     
         1 . A method of manufacturing a semiconductor device including a MISFET, the method comprising the steps of:
 (a) preparing a semiconductor substrate;   (b) forming a laminate film for a gate insulating film including a HfON film and a HfSiON film stacked over the HfON film; and   (c) after the step (b), forming a metal gate electrode including a metal nitride film in a lowermost layer thereof over the laminate film.   
     
     
         2 . A method of manufacturing a semiconductor device according to  claim 1 , the method further comprising the step of:
 (a1) after the step (a) and before the step (b), forming an insulating layer made of a silicon oxide or a silicon oxynitride over the semiconductor substrate,   wherein, in the step (b), a laminate film including the HfON film and the HfSiON film stacked over the HfON film is formed over the insulating layer.   
     
     
         3 . A method of manufacturing a semiconductor device according to  claim 2 ,
 wherein the step (b) includes the steps of:   (b1) forming a HfO film over the insulating layer;   (b2) forming a HfSiO film over the HfO film; and   (b3) subjecting a laminate film including the HfO film and the HfSiO film to nitridation treatment to form the laminate film including the HfON film and the HfSiON film.   
     
     
         4 . A method of manufacturing a semiconductor device according to  claim 3 ,
 wherein the nitridation treatment in the step (b3) uses plasma nitridation.   
     
     
         5 . A method of manufacturing a semiconductor device according to  claim 4 ,
 wherein the steps (b1) and (b2) are continuously performed without exposing the semiconductor substrate to an atmosphere.   
     
     
         6 . A method of manufacturing a semiconductor device according to  claim 5 ,
 wherein a thickness of the HfO film formed in the step (b1) is larger than a thickness of the HfSiO film formed in the step (b2).   
     
     
         7 . A method of manufacturing a semiconductor device according to  claim 6 ,
 wherein a thickness of the HfSiON film formed in the step (b3) is not less than 0.2 nm.   
     
     
         8 . A method of manufacturing a semiconductor device according to  claim 7 ,
 wherein a thickness of the HfSiON film formed in the step (b3) is 0.2 to 0.55 nm.   
     
     
         9 . A method of manufacturing a semiconductor device according to  claim 8 ,
 wherein a thickness of the HfON film formed in the step (b3) is 0.6 to 0.85 nm.   
     
     
         10 . A method of manufacturing a semiconductor device according to  claim 9 ,
 wherein, in the HfSiON film formed in the step (b3), a Hf concentration is 2/3 to 1.5 times as high as a Si concentration.   
     
     
         11 . A method of manufacturing a semiconductor device according to  claim 10 ,
 wherein the metal nitride film is a titanium nitride film.   
     
     
         12 . A method of manufacturing a semiconductor device including an n-channel first MISFET in a first region of a semiconductor substrate and a p-channel second MISFET in a second region of the semiconductor substrate, the method comprising the steps of:
 (a) preparing the semiconductor substrate;   (b) forming an insulating layer made of a silicon oxide or a silicon oxynitride over the semiconductor substrate in the first region and the second region;   (c) forming a HfO film over the insulating layer in the first region and the second region;   (d) forming a HfSiO film over the HfO film in the first region and the second region;   (e) after the step (d), subjecting the HfO film and the HfSiO film to nitridation treatment to form a laminate film including a HfON film and a HfSiON film;   (f) after the step (e), forming an Al-containing film containing Al over the laminate film in the first region and the second region;   (g) after the step (f), forming a mask layer over the Al-containing film in the first region and the second region;   (h) after the step (g), removing the mask layer and the Al-containing film from the first region to leave the mask layer and the Al-containing film in the second region;   (i) after the step (h), forming a rare-earth-element-containing film containing a rare earth element over the HfSiON film in the first region and over the mask layer in the second region;   (j) after the step (i), performing heat treatment to cause a reaction between each of the HfON film and the HfSiON film and the rare-earth-element-containing film in the first region and cause a reaction between each of the HfON film and the HfSiON film and the Al-containing film in the second region;   (k) after the step (j), removing the rare-earth-element-containing film which has not reacted in the step (j) and the mask film; and   (l) after the step (k), forming a first metal gate electrode for the first MISFET in the first region and forming a second metal gate electrode for the second MISFET in the second region.   
     
     
         13 . A method of manufacturing a semiconductor device according to  claim 12 ,
 wherein the step (l) includes the steps of:   (l1) after the step (k), forming a metal nitride film over the semiconductor substrate in the first region and the second region;   (l2) forming a silicon film over the metal nitride film; and   (l3) after the step (l2), patterning the silicon film and the metal nitride film to form the first metal gate electrode in the first region and form the second metal gate electrode in the second region.   
     
     
         14 . A method of manufacturing a semiconductor device including an n-channel first MISFET in a first region of a semiconductor substrate and a p-channel second MISFET in a second region of the semiconductor substrate, the method comprising the steps of:
 (a) preparing the semiconductor substrate;   (b) forming an insulating layer made of a silicon oxide or a silicon oxynitride over the semiconductor substrate in the first region and the second region;   (c) forming a HfO film over the insulating layer in the first region and the second region;   (d) forming a HfSiO film over the HfO film in the first region and the second region;   (e) after the step (d), subjecting the HfO film and the HfSiO film to nitridation treatment to form a laminate film including a HfON film and a HfSiON film;   (f) after the step (e), forming a rare-earth-element-containing film containing a rare earth element over the laminate film in the first region and the second region;   (g) after the step (f), forming a mask layer over the rare-earth-element-containing film in the first region and the second region;   (h) after the step (g), removing the mask layer and the rare-earth-element-containing film from the first region to leave the mask layer and the rare-earth-element-containing film in the second region;   (i) after the step (h), forming an Al-containing film containing Al over the HfSiON film in the first region and over the mask layer in the second region;   (j) after the step (i), performing heat treatment to cause a reaction between each of the HfON film and the HfSiON film and the rare-earth-element-containing film in the first region and cause a reaction between each of the HfON film and the HfSiON film and the Al-containing film in the second region;   (k) after the step (j), removing the Al-containing film which has not reacted in the step (j) and the mask film; and   (l) after the step (k), forming a first metal gate electrode for the first MISFET in the first region and forming a second metal gate electrode for the second MISFET in the second region.   
     
     
         15 . A method of manufacturing a semiconductor device according to  claim 14 ,
 wherein the step (l) includes the steps of:   (l1) after the step (k), forming a metal nitride film over the semiconductor substrate in the first region and the second region;   (l2) forming a silicon film over the metal nitride film; and   (l3) after the step (l2), patterning the silicon film and the metal nitride film to form the first metal gate electrode in the first region and form the second metal gate electrode in the second region.