Method for producing mold for minute pattern transfer, method for producing diffraction grating using the same, and method for producing organic el element including the diffraction grating

Abstract

A method for producing a mold includes: applying a block copolymer solution made of first and second polymers on a base member; performing a first annealing process at a temperature higher than Tg of the block copolymer after drying the coating film; forming a concavity and convexity structure on the base member by removing the second polymer by an etching process; performing a second annealing process of the concavity and convexity structure at a temperature higher than Tg of the first polymer; forming a seed layer on the structure; laminating or stacking a metal layer on the seed layer by an electroforming; and peeling off the metal layer from the base member. The second annealing process enables satisfactory transfer of a concavity and convexity structure on the base member onto the metal layer.

What is claimed is: 
     
         1 . A mold for minute pattern transfer produced by a producing method, the producing method comprising
 a step of applying a block copolymer solution made of at least a first polymer and a second polymer on a surface of a base member;   a step of drying a coating film on the base member;   a first heating step for heating the coating film after the drying at a temperature higher than a glass transition temperature of a block copolymer of the block copolymer solution;   an etching step for etching the coating film after the first heating step to remove the second polymer so that a concavity and convexity structure is formed on the base member;   a second heating step for heating the concavity and convexity structure at a temperature higher than a glass transition temperature of the first polymer;   a step of forming a seed layer on the concavity and convexity structure after the second heating step;   a step of or stacking a metal layer on the seed layer by an electroforming; and   a step of peeling off the base member having the concavity and convexity structure from the metal layer and the seed layer.   
     
     
         2 . A diffraction grating comprising a concavity and convexity structure on a surface thereof,
 wherein the diffraction grating is produced by a method comprising:   pressing the mold obtained by the method for producing the mold as defined in  claim 1  to a transparent substrate to which a curable resin has been applied;   curing the curable resin; and   detaching the mold from the transparent substrate to obtain a structure having a concavity and convexity structure on the transparent substrate.   
     
     
         3 . The diffraction grating of  claim 2 ,
 wherein the diffraction grating is produced by   pressing the structure to a substrate to which a sol-gel material has been applied;   curing the sol-gel material; and   detaching the structure from the substrate to obtain the diffraction grating having a concavity and convexity structure made of the sol-gel material.   
     
     
         4 . The diffraction grating according to  claim 2 , wherein a cross-section shape of the concavity and convexity structure has a chevron shape; and in a case that a Fourier-transformed image is obtained by performing a two-dimensional fast Fourier-transform processing on an concavity and convexity analysis image obtained by an analyzing a planar shape of the concavity and convexity structure with an atomic force microscope, the Fourier-transformed image shows an annular pattern substantially centered at an origin at which an absolute value of wavenumber is 0 μm −1 , and the annular pattern is present within a region where the absolute value of wavenumber is within a range of 10 μm −1  or less. 
     
     
         5 . The diffraction grating according to  claim 3 , wherein a cross-section shape of the concavity and convexity structure has a chevron shape; and in a case that a Fourier-transformed image is obtained by performing a two-dimensional fast Fourier-transform processing on an concavity and convexity analysis image obtained by an analyzing a planar shape of the concavity and convexity structure with an atomic force microscope, the Fourier-transformed image shows an annular pattern substantially centered at an origin at which an absolute value of wavenumber is 0 μm −1 , and the annular pattern is present within a region where the absolute value of wavenumber is within a range of 10 μm −1  or less. 
     
     
         6 . The diffraction grating according to  claim 2 , wherein a kurtosis of the cross-section shape of the concavity and convexity structure is −1.2 or more. 
     
     
         7 . The diffraction grating according to  claim 6 , wherein the kurtosis of the cross-section shape of the concavity and convexity structure is −1.2 to 1.2. 
     
     
         8 . The diffraction grating according to  claim 2 , wherein an average pitch of a cross-section of the concavity and convexity structure is 10 to 600 nm. 
     
     
         9 . An organic EL element produced by stacking a transparent electrode, an organic layer, a metal electrode in this order on the concavity and convexity structure of the diffraction grating produced by the method for producing the diffraction grating as defined in  claim 2 .