Semiconductor device and method for manufacturing the same

Abstract

In order to suppress an increase of depressions, etc. to occur on a copper based alloy layer during polishing when a copper based alloy inlaid wiring is formed with the damascene method in grooves formed in an insulating film, the polishing rate for the lower metallic layer is set not less than five times faster than the etching rate for the same and the polishing rate for the insulating film is set lower than the polishing rate for the lower metallic layer when the upper metallic layer 13 to become a wiring and the lower metallic layer 12 to become a barrier are polished respectively. Thus, the object damascene wiring can be formed with less erosion on each of insulating layers and dishing on each of metallic layers respectively.

1 . A method for manufacturing a semiconductor device, comprising the steps of: 
 forming at least an insulating film on a substrate;    forming at least a via hole in said insulating film;    forming a first conductor film extended from a groove to said insulating film surface;    forming a second film on said first conductor film extended from said groove to said insulating film surface;    polishing said second conductor film; and    polishing said first conductor film at a polishing rate not less than five times the polishing rate for said insulating film.    
     
     
         2 . A method for manufacturing a semiconductor device in accordance with  claim 1 , wherein 
 said second conductor film is a copper film or a copper based alloy film.    
     
     
         3 . A method for manufacturing a semiconductor device in accordance with  claim 1 , wherein 
 said conductor film is a film containing at least any of titanium, tantalum, and tungsten atoms.    
     
     
         4 . A method for manufacturing a semiconductor device in accordance with  claim 1 , wherein 
 the step for polishing said first conductor film uses an inhibitor added a polishing agent in which an inhibitor for said second conductor film is contained.    
     
     
         5 . A method for manufacturing a semiconductor device in accordance with  claim 4 , wherein 
 said inhibitor contains any of BTA derivatives such as BTA (Benzotriazole), BTA carboxylic acid, etc., as well as dodecanethiol, Triazole, Tritriazole, and derivatives of those substances.    
     
     
         6 . A method for manufacturing a semiconductor device in accordance with  claim 4 , wherein 
 the step for polishing said first conductor film uses a polishing agent obtained by adding second inhibitor, which contains at least one of Poly-acrylic acid and Poly-methacryllc acid, or ammonium acid salts of those substances, or a compound of those substances, or ethlenediaminetetraacetic acid to said first inhibitor.    
     
     
         7 . A method for manufacturing a semiconductor device in accordance with  claim 4 , wherein 
 the step for polishing said first conductor film uses a polishing agent containing a first amount of said inhibitor;    the step for polishing said second conductor film uses a polishing agent containing a second amount of said inhibitor; and    said first amount is more than said second amount.    
     
     
         8 . A method for manufacturing a semiconductor device in accordance with  claim 7 , wherein 
 said first amount is 0.01 wt % more than said second amount.    
     
     
         9 . A method for manufacturing a semiconductor device in accordance with  claim 4 , wherein 
 the step for polishing said second conductor film uses said inhibitor at a concentration not less than 0.01 wt % and not more than 0.05 wt %; and    the step for polishing said first conductor film uses said inhibitor at a concentration not less than 0.04 wt % and not more than 1 wt %.    
     
     
         10 . A method for manufacturing a semiconductor device in accordance with  claim 1 , wherein 
 the step for polishing said second conductor film uses a polishing agent to which an inhibitor is added;    the concentration of said inhibitor is decided so that the polishing rate becomes not less than 40% and not more than 95% of that for said second conductor film when said inhibitor is not added.    
     
     
         11 . A method for manufacturing a semiconductor device in accordance with  claim 1 , wherein 
 the step for polishing said first conductor film uses said inhibitor at a concentration set so as to make the polishing rate for said first conductor film become not more than 30% of that for said first conductor film when said inhibitor is not used.    
     
     
         12 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming an insulating film on a substrate;    forming a via hole in said insulating film;    forming a first conductor film extended from said via hole to said insulating film surface;    forming a second film on said first conductor film extended from said groove to said insulating film surface;    polishing said second conductor film; and    polishing said first conductor film at a polishing rate not less than seven times the polishing rate of said insulating film.    
     
     
         13 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming an insulating film on a substrate;    forming a via hole in said insulating film;    forming a first conductor film extended from said via hole to said insulating film surface;    forming a second conductor film on said first conductor film extended from a groove to said insulating film surface;    polishing said second conductor film; and    polishing said first conductor film at a polishing rate not less than 10 times that for said insulating film.    
     
     
         14 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming an insulating film provided with a via hole on a substrate;    forming a first metal film extended from inside to outside of said via hole;    forming a second metal film on said first metal film;    polishing said second metal film; and    polishing said first metal film at a polishing rate more than five times the etching rate for said second metal film.    
     
     
         15 . A method for manufacturing a semiconductor device in accordance with  claim 14 , wherein 
 the step for polishing said first metal film is carried out in an acidic region.    
     
     
         16 . A method for manufacturing a semiconductor device in accordance with  claim 14 , wherein 
 the step for polishing said second metal film is carried out in an acidic region.    
     
     
         17 . A method for manufacturing a semiconductor device in accordance with  claim 16 , wherein 
 the step for polishing said first metal film forms a metal film consisting of two or more layers.    
     
     
         18 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming an insulating film provided with a via hole on a substrate;    forming a first metal film extended from inside to outside of said via hole;    forming a second metal film on said first metal film;    polishing said second metal film; and    polishing said first metal film at a polishing rate of more than ten times the etching rate for said second metal film.    
     
     
         19 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming an insulating film provided with a via hole on a substrate;    forming a first metal film extended from inside to outside of said via hole;    forming a second metal film on said first metal film;    polishing said second metal film; and    polishing said first metal film at a polishing rate of more than fifteen times the etching rate for said second metal film.    
     
     
         20 . A method for manufacturing a semiconductor device in accordance with  claim 19 , wherein 
 said substrate is 150 mm or more in diameter.    
     
     
         21 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming an insulating film provided with a via hole on a substrate;    forming a first metal film extended from inside to outside of said via hole;    forming a second metal film on said first metal film;    polishing said second metal film;    polishing said second metal film at a polishing rate of more than five times the etching rate in said polishing step, and    polishing said first metallic layer.    
     
     
         22 . A method for manufacturing a semiconductor device in accordance with  claim 21 , wherein 
 said first metallic layer is polished at a polishing rate of not less than five times the etching rate for said second metallic layer.    
     
     
         23 . A method for manufacturing a semiconductor device, comprising the steps of: 
 forming a first conductor film on said groove-formed insulating film so as to be extended from inside to outside each of said grooves;    forming a second conductor film on said first conductor film;    polishing both of said first and second conductor films using first polishing agent; and    polishing unpolished portions of said second conductor film at a polishing rate of not less than 5 times that for said insulating film using second polishing agent.    
     
     
         24 . A method for manufacturing a semiconductor device in accordance with  claim 23 , wherein 
 said first polishing agent consists of inorganic solid abrasive powder whose concentration is 0.1 wt % or more.    
     
     
         25 . A method for manufacturing a semiconductor device in accordance with  claim 23 , wherein 
 at least either said first polishing agent or said second polishing agent contains alumina or silica.    
     
     
         26 . A method for manufacturing a semiconductor device in accordance with  claim 23 , wherein 
 said first polishing agent contains hydrogen peroxide solution, organic acid, and an inhibitor.    
     
     
         27 . A method for manufacturing a semiconductor device in accordance with  claims 23  to  26 , wherein 
 said first polishing agent contains said first inhibitor consisting of at least one of BTA (Benzotriazole), BTA derivatives such as BTA carboxylic acid, etc., dodecanethiol, Triazole, Tritriazole, and derivatives or compounds of those substances, as well as a second inhibitor consisting of at least one of Poly-acrylic acid, Poly-methacrylic acid, and ammonium acid salts or compounds of those substances, or ethlenediaminetetraacetic acid.  
 
     
     
         28 . A method for manufacturing a semiconductor device in accordance with  claim 27 , wherein 
 the concentration of said first inhibitor is not less than 0.01 wt % and not more than 0.05 wt %.    
     
     
         29 . A method for manufacturing a semiconductor device in accordance with  claim 27  or  28 , wherein 
 the concentration of said first inhibitor is set so as to keep a polishing rate of not more than 95% and not less than 40% of that for said second conductor film when said polishing agent does not include said first inhibitor.  
 
     
     
         30 . A method for manufacturing a semiconductor device in accordance with  claims 23  to  29 , wherein 
 the pH of said second polishing agent is not less than 1 and not more than 6.  
 
     
     
         31 . A method for manufacturing a semiconductor device in accordance with  claims 23  to  30 , wherein 
 the concentration of the fixed abrasive contained in said second polishing agent is not more than 0.1 wt %.  
 
     
     
         32 . A method for manufacturing a semiconductor device in accordance with  claims 23  to  31 , wherein 
 said second polishing agent contains an organic acid and an oxidizer.  
 
     
     
         33 . A method for manufacturing a semiconductor device in accordance with  claims 23  to  32 , wherein 
 said organic acid contains malonic acid, fumaric acid, malic acid, adipic acid, benzoic acid, 4 cyano benzoic acid, phthalic acid, uric acid, oxalic acid, tartaric acid, lactic acid, succinic acid, citric acid, or at least any of salts obtained from reaction of those acids.  
 
     
     
         34 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming a first conductor film extended from inside to outside of a groove on a groove-formed insulating film;    forming a second conductor film on said first conductor film;    polishing said second conductive film selectively with respect to said first conductor film; and    polishing said first conductor film at a polishing rate of not less than five times that for said insulating film.    
     
     
         35 . A method for manufacturing a semiconductor device, comprising the steps of: 
 forming an insulating film on a substrate;    forming a via hole in said insulating film;    forming a first conductor film so as to be extended from said via hole onto said insulating film;    forming a second conductor film on said first conductor film;    polishing said second conductor film using a polishing agent containing inorganic abrasive powder whose concentration is not more than 0.1 wt %; and    polishing said first conductor film at a polishing rate of not less than five times the polishing rate for said insulating film.    
     
     
         36 . A method for manufacturing a semiconductor device in accordance with  claim 35 , wherein 
 the step for polishing said first conductor film uses a polishing agent containing inorganic abrasive not less than 0.1 wt %.    
     
     
         37 . A method for manufacturing a semiconductor device in accordance with  claim 35 , wherein 
 said second polishing agent contains at least a hydrogen peroxide solution, an organic acid, and an inhibitor.    
     
     
         38 . A method for manufacturing a semiconductor device in accordance with  claims 35  to  37 , wherein 
 said polishing agent contains said first inhibitor consisting of at least one of BTA (Benzotriazole), BTA derivatives such as BTA carboxylic acid, etc., dodecanethiol, Triazole, Tritriazole, and derivatives or compounds obtained from reaction of those acids, as well as a second inhibitor consisting of at least one of Poly-acrylic acid, Poly-methacrylic acid, and salts or compounds obtained from reaction of those acids with ammonium, or ethlenediaminetetraacetic acid.  
 
     
     
         39 . A method for manufacturing a semiconductor device in accordance with  claims 35  to  38 , wherein 
 the step for polishing said first conductor film uses a second polishing agent containing inorganic abrasive whose concentration is 0.1 wt % or under.  
 
     
     
         40 . A method for manufacturing a semiconductor device in accordance with  claim 39 , wherein 
 said second polishing agent contains a hydrogen peroxide solution, an organic acid, and an inhibitor.    
     
     
         41 . A method for manufacturing a semiconductor device in accordance with  claim 39 , wherein 
 said second polishing agent contains said first inhibitor consisting of at least one of BTA (Benzotriazole), BTA derivatives such as BTA carboxylic acid, etc., dodecanethiol, Triazole, Tritriazole, and derivatives or compounds obtained from of those acids, as well as a second inhibitor consisting of at least one of Poly-acrylic acid, Poly-methacrylic acid, and salts or compounds obtained from reaction of those acids with ammonium, or ethlenediaminetetraacetic acid.    
     
     
         42 . A method for manufacturing a semiconductor device, comprising steps of: 
 forming a first conductor film extended from inside to outside of said via hole on a via-hole-formed insulating film;    forming a second conductor film on said first conductor film;    polishing said second conductor film using a first platen; and    polishing said first conductor film inlaid in each of said via hole using a second platen so as to become higher than said second conductor film formed in said via hole.    
     
     
         43 . A method for manufacturing a semiconductor device in accordance with  claim 42 , wherein 
 said first and second platens are different from each other.    
     
     
         44 . A method for manufacturing a semiconductor device in accordance with  claim 42 , wherein 
 at least one of the steps for polishing using said first and second platens uses a polishing pad containing fixed abrasive powder.    
     
     
         45 . A semiconductor device, comprising: 
 a substrate;    an insulating film formed an said substrate and provided with a via hole;    a first conductor film formed in said via hole; and    a second conductor film formed on said first conductor film so as to become lower than said first conductor film formed in said via hole.    
     
     
         46 . A method for manufacturing a semiconductor device, comprising the steps of: 
 forming a first insulating film on a substrate;    forming a second insulating film on said first insulating film;    forming a first via hole in said second insulating film and a second via hole in said first insulating film;    forming a first conductor film so as to be extended from both of said second and first via holes onto said second insulating film surface;    forming a second conductor film so as to be laminated on said first conductor film and extended from both of said second and first via holes onto said second insulating film surface;    polishing said second conductor film; and    polishing said first conductor film at a polishing rate of not less than five times the polishing rate for said second insulating film.