Masking material for dry etching

Abstract

The object of the present invention is to provide a masking material for dry etching, which is suitable for fine processing of a magnetic film as thin as a few nm such as NiFe or CoFe constituting a TMR film and capable of simplifying the process for producing a TMR element and reducing production costs related to facilities and materials. This object was solved by a masking material for dry etching of a magnetic material by using a mixed gas of carbon monoxide and a nitrogenous compound as etching gas, which comprises a metal (tantalum, tungsten, zirconium or hafnium) with a melting or boiling point increasing upon conversion thereof into a nitride or carbide.

1 - 3 . (canceled)  
     
     
         4 . A method for producing a TMR element which comprises dry etching using a metal film comprising a metal having a specific physical property that its melting point or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, as a masking material for dry etching, and using a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas.  
     
     
         5 . The method as claimed in  claim 4 , wherein the metal film is tantalum film.  
     
     
         6 . The method as claimed in  claim 4 , wherein the metal film is any one of tungsten film, zirconium film or hafnium film.  
     
     
         7 . A method for producing a TMR element which comprises dry etching a plurality of laminate films including magnetic film, using a metal film comprising a metal having a specific physical property that its melting point or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, as a masking material for dry etching, and using a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas.  
     
     
         8 . The method as claimed in  claim 7 , wherein the metal film is tantalum film.  
     
     
         9 . The method as claimed in  claim 7 , wherein the metal film is any one of tungsten film, zirconium film or hafnium film.  
     
     
         10 . A method for producing a TMR element which comprises fine processing a TMR element using tantalum as a masking material, and a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas, wherein a plurality of films including magnetic film composing the TMR element are dry etched.  
     
     
         11 . The method as claimed in  claim 10 , wherein a tantalum film is included in a plurality of films including magnetic film composing the TMR element.  
     
     
         12 . The method as claimed in  claim 10 , wherein tantalum used as a masking material acts as a component layer for the TMR element.  
     
     
         13 . The method as claimed in  claim 10 , wherein a tantalum film used as a masking material acts as a protective film composing the TMR element.  
     
     
         14 . A method for producing a magnetic device which comprises dry etching using a metal film comprising a metal having a specific physical property that its melting point or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, as a masking material for dry etching, and using a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas.  
     
     
         15 . The method as claimed in  claim 14 , wherein the metal film is tantalum film.  
     
     
         16 . The method as claimed in  claim 14 , wherein the metal film is any one of tungsten film, zirconium film or hafnium film.  
     
     
         17 . A method for producing a magnetic device which comprises dry etching a plurality of laminate films including magnetic film, using a metal film comprising a metal having a specific physical property that its melting point or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, as a masking material for dry etching, and using a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas.  
     
     
         18 . The method as claimed in  claim 17 , wherein the metal film is tantalum film.  
     
     
         19 . The method as claimed in  claim 17 , wherein the metal film is any one of tungsten film, zirconium film or hafnium film.  
     
     
         20 . A method for producing a magnetic device which comprises fine processing a magnetic device using tantalum as a masking material, and a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas, wherein a plurality of films including magnetic film composing the magnetic device are dry etched.  
     
     
         21 . The method as claimed in  claim 20 , wherein a tantalum film is included in a plurality of films including magnetic film composing the magnetic device.  
     
     
         22 . The method as claimed in  claim 20 , wherein tantalum used as a masking material acts as a component layer for the magnetic device.  
     
     
         23 . The method as claimed in  claim 20 , wherein a tantalum film used as a masking material acts as a protective film composing the magnetic device.  
     
     
         24 . A method for producing a MRAM using a TMR structure which comprises dry etching using a metal film comprising a metal having a specific physical property that its melting point or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, as a masking material for dry etching, and using a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas.  
     
     
         25 . The method as claimed in  claim 24 , wherein the metal film is tantalum film.  
     
     
         26 . The method as claimed in  claim 24 , wherein the metal film is any one of tungsten film, zirconium film or hafnium film.  
     
     
         27 . A method for producing a MRAM using a TMR structure which comprises dry etching a plurality of laminate films including magnetic film, using a metal film comprising a metal having a specific physical property that its melting point or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, as a masking material for dry etching, and using a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas.  
     
     
         28 . The method as claimed in  claim 27 , wherein the metal film is tantalum film.  
     
     
         29 . The method as claimed in  claim 27 , wherein the metal film is any one of tungsten film, zirconium film or hafnium film.  
     
     
         30 . A method for producing a MRAM using a TMR structure which comprises fine processing a TMR structure using tantalum as a masking material, and a mixed gas of carbon monoxide and a nitrogeneous compound as etching gas, wherein a plurality of films including magnetic film composing the TMR structure are dry etched.  
     
     
         31 . The method as claimed in  claim 30 , wherein a tantalum film is included in a plurality of films including magnetic film composing the TMR structure.  
     
     
         32 . The method as claimed in  claim 30 , wherein tantalum used as a masking material acts as a component for the TMR structure.  
     
     
         33 . The method as claimed in  claim 30 , wherein a tantalum film used as a masking material acts as a protective film composing the TMR structure.  
     
     
         34 . A masking material for dry etching of a magnetic material by using a mixed gas of carbon monoxide and a nitrogenous compound as etching gas, which comprises a metal having a specific physical property that its melting or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, and wherein the masking material is tantalum and is in contact with the etching gas.  
     
     
         35 . A masking material for dry etching of a magnetic material by using a mixed gas of carbon monoxide and a nitrogenous compound as etching gas, which comprises a metal having a specific physical property that its melting or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, and wherein the masking material is tungsten and is in contact with the etching gas.  
     
     
         36 . A masking material for dry etching of a magnetic material by using a mixed gas of carbon monoxide and a nitrogenous compound as etching gas, which comprises a metal having a specific physical property that its melting or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, and wherein the masking material is zirconium and is in contact with the etching gas.  
     
     
         37 . A masking material for dry etching of a magnetic material by using a mixed gas of carbon monoxide and a nitrogenous compound as etching gas, which comprises a metal having a specific physical property that its melting or boiling point, when it is converted into a nitride or carbide is higher than that of in the form of single metal, and wherein the masking material is hafnium and is in contact with the etching gas.