Method of cleaning surface of semiconductor substrate, method of manufacturing thin film, method of manufacturing semiconductor device, and semiconductor device

Abstract

A technique that enables the formation of a low resistivity barrier film at low temperatures, and a technique that enables the removal of impurities (such as, oxides, fluorides, carbides, and nitrides) from the surfaces of semiconductor substrates and metal thin films at low temperatures. A catalyst is placed inside a vacuum chamber and heated, a raw material gas and a reactive gas are introduced alternately into the vacuum chamber, and a reaction is effected between the raw material gas adsorbed to the surface of an object, and radicals generated by decomposition of the reactive gas on contact with the catalyst, thereby depositing a thin film on the object. A low resistivity barrier film can be obtained at low temperatures. H 2 gas, NH 3 gas, SiH 4 gas, or the like can be used as the reactive gas. Furthermore, the catalyst is placed in a vacuum atmosphere, and with the catalyst being heated, a treatment gas having a hydrogen atom in its chemical structure is brought into contact with the catalyst, thereby generating radicals. By exposing the surface of an object to be treated to these radicals, impurities (such as, oxides, fluorides or the like) are removed. Because the generated radicals are extremely reactive, a superior cleaning effect is achieved, even with the object being at low temperatures.

1 . A method of manufacturing a thin film comprising: 
 performing a raw material gas introduction step and a reactive gas introduction step alternately so as to form a thin film on the surface of an object to be treated positioned inside a vacuum chamber,    wherein a raw material gas introduction step is supplies raw material gas into a vacuum chamber,    wherein a reactive gas introduction step is introduces a reactive gas including a hydrogen atom in its chemical structure into the vacuum chamber during the introduction of the raw material gas halted, and brings the reactive gas into contact with a heated catalyst.    
   
   
       2 . The method of manufacturing a thin film according to  claim 1 , further comprising a step of: 
 a raw material gas evacuation step of evacuating the inside of the vacuum chamber during introduction of both the raw material gas and the reactive gas halted, after the raw material gas introduction step, and prior to the reactive gas introduction step.    
   
   
       3 . The method of manufacturing a thin film according to  claim 1 , further comprising the step of: 
 a reactive gas evacuation step of evacuating the inside of the vacuum chamber during introduction of both the raw material gas and the reactive gas halted, after the reactive gas introduction step, prior to returning to the raw material gas introduction step.    
   
   
       4 . The method of manufacturing a thin film according to  claim 1 , wherein the reactive gas is one or more gases selected from the group consisting of H 2  gas, NH 3  gas, SiH 4  gas, NH 2 NH 2  gas, and H 2 O gas.  
   
   
       5 . The method of manufacturing a thin film according to  claim 1 , wherein the raw material gas is an organometallic compound gas.  
   
   
       6 . The method of manufacturing a thin film according to  claim 1 , wherein a metal wiring film is exposed on at least a part of the surface of the object, and a thin film is formed on the exposed metal wiring film.  
   
   
       7 . The method of manufacturing a thin film according to  claim 6 , wherein an insulating film is disposed on the metal film, and the thin film is formed on the metal wiring film exposed at the bottom of a hole formed in the insulating film.  
   
   
       8 . The method of manufacturing a thin film where a pretreatment step is conducted prior to the formation of the thin film according to  claim 1 , the pretreatment step comprising the steps of: 
 positioning the object inside the vacuum chamber,    introducing the reactive gas into the vacuum chamber without introducing the raw material gas during the catalyst in a heated state, and    bringing the reactive gas into contact with the catalyst.    
   
   
       9 . A method of manufacturing a semiconductor device, wherein 
 the object is a semiconductor substrate, and the thin film is formed on the semiconductor substrate using the method of manufacturing a thin film according to  claim 1 .    
   
   
       10 . A semiconductor device comprising a thin film formed using the method of manufacturing a thin film according to  claim 1 .  
   
   
       11 . A cleaning method of a surface of a semiconductor substrate, comprising the steps of: 
 generating radicals by bringing a treatment gas having a hydrogen atom in its chemical structure into contact with a heated catalyst; and    reducing impurities positioned on at least a part of the surface of the object by bringing the radicals into contact with the surface of the object.    
   
   
       12 . The cleaning method according to  claim 11 , 
 wherein the treatment gas is one or more gases selected from the group consisting of H 2  gas, NH 3  gas, SiH 4  gas, NH 2 NH 2  gas, and H 2 O gas.    
   
   
       13 . The cleaning method according to  claim 11 , wherein 
 a conductive material is exposed on the surface of the object.    
   
   
       14 . The cleaning method according to  claim 11 , 
 wherein the treatment gas is either a single gas or a mixed gas comprising two or more gases selected from the group consisting of H 2  gas, NH 3  gas, SiH 4  gas, NH 2 NH 2  gas, and H 2 O gas.    
   
   
       15 . A method of manufacturing a semiconductor device, comprising the steps of: 
 generating radicals by bringing a treatment gas having a hydrogen atom in its chemical structure into contact with a heated catalyst;    reducing impurities positioned on at least a part of the surface of a semiconductor substrate by bringing the radicals into contact with the surface of a semiconductor substrate;    forming a conductive material on at least the surface where the impurities have been reduced.    
   
   
       16 . The method of manufacturing a semiconductor device according to  claim 15 , 
 wherein the treatment gas is either a single gas or a mixed gas comprising two or more gases selected from the group consisting of H 2  gas, NH 3  gas, SiH 4  gas, NH 2 NH 2  gas, and H 2 O gas.    
   
   
       17 . The method of manufacturing a semiconductor device according to  claim 15 , 
 wherein a conductive material patterned into predetermined shape and exposed on a part of the surface of the substrate is brought into contact with the radicals.    
   
   
       18 . The method of manufacturing a semiconductor device according to  claim 17 , 
 wherein an insulating film is disposed on the conductive material, and the conductive material is exposed at the bottom of a hole formed in the insulating film.    
   
   
       19 . The method of manufacturing a semiconductor device according to  claim 15 , wherein 
 the conductive material is a material selected from the group consisting of a copper film, a TiN film, an Al film, and a Si crystal.