Phase shift mask blank, photo mask blank, and manufacturing apparatus and method of blanks

Abstract

There is provided a manufacturing apparatus and method able to manufacture a phase shift mask blank in which a total number of particles and pinholes having a diameter larger than about a half of an exposure wavelength in a light semi-transmission film is 0.1 or less per square centimeter. In a DC magnetron sputtering apparatus for manufacturing a halftone phase shift mask blank, for example, a target plane is disposed downwards with respect to a gravity direction, a whole-surface erosion cathode is used, a corner portion 5 a of an end of a target and a corner portion of an earth shield are chamfered (R processed), a target end 5 b, an exposed backing plate surface 4 b and the surface of an earth shield 12 are roughened, and the earth shield 12 is disposed above a target plane d (on a backing plate side).

What is claimed is:  
     
         1 . A manufacturing method of a photo mask blank having a thin film for forming a pattern on a transparent substrate, comprising steps of: 
 directing the surface of a target downwards and the surface of a substrate upwards with respect to a gravity direction; shielding a peripheral edge of said substrate to prevent the film from being formed on the peripheral edge; and sputtering/forming said thin film.    
     
     
         2 . A manufacturing method of a photo mask blank having a thin film for forming a pattern on a transparent substrate, comprising a step of: 
 manufacturing said thin film using a DC magnetron sputtering apparatus comprising at least a sputtering target, a magnetron cathode with the target attached thereto, a substrate holder disposed opposite to said target, and a shield disposed on an inner wall of a vacuum tank inside the vacuum tank,    wherein the surface of a target is directed downwards with respect to a gravity direction, and    the apparatus has a mechanism for reducing film formation on a non-sputtered area on the target and the surface of the shield.    
     
     
         3 . The manufacturing method according to  claim 2  wherein said mechanism for reducing the film formation onto the non-sputtered area on the target comprises a mechanism in which a whole-surface erosion cathode is used as the magnetron cathode, a mechanism for shielding the non-sputtered area on the target, or a mechanism for roughening the surface of a non-sputtered portion on the target.  
     
     
         4 . The manufacturing method according to  claim 3  wherein said mechanism for reducing the film formation onto the non-sputtered area on the target further comprises a mechanism for forming a corner in the target into a curved surface, and roughening an end surface of the target.  
     
     
         5 . The manufacturing method according to  claim 2  wherein the mechanism for reducing the film formation on the shield surface keeps the shield at a constant temperature, and a shape of the shield is designed so that a relative film formation speed t in the following equation (i) in at least a shield position in the vicinity of the target is prevented from being larger than a value in a position on the substrate:  
         t =cos θ 1 ×Sin(θ 1 −θ 2 )/ r   2    (i)  
       (in the equation (i), r denotes a distance between a target center and a shield position, θ 1  denotes an angle of a line connecting the target center to the shield position with respect to a normal of a target plane, θ 2  denotes an angle of a shield plane with respect to the normal of the target plane, and t denotes the relative film formation speed in the shield position defined by r and θ 1 ).  
     
     
         6 . The manufacturing method according to  claim 5  wherein the mechanism for reducing the film formation onto said shield surface comprises a mechanism for forming a corner in the shield into a curved surface, roughening the surface of the shield, and disposing an earth shield above the target plane.  
     
     
         7 . The manufacturing method according to  claim 2  wherein the apparatus further comprises a backing plate to which the target is to be attached, and the surface of the backing plate is roughened.  
     
     
         8 . The manufacturing method according to  claim 2  wherein the apparatus further comprises a shield plate for preventing the film from being formed on a peripheral portion of the substrate.  
     
     
         9 . A photo mask blank manufactured using the manufacturing method according to  claim 1 .  
     
     
         10 . A photo mask blank manufactured using the manufacturing method according to  claim 2 .  
     
     
         11 . A photo mask blank having a thin film for forming a pattern on a transparent substrate, 
 wherein a total number of particles and pinholes having a diameter larger than a diameter equivalent in size to an exposure wavelength for use in said blank as a mask is 0.1 or less per square centimeter.    
     
     
         12 . A photo mask blank having a thin film for forming a pattern on a transparent substrate, 
 wherein an exposure wavelength for use in said blank as a mask has a center wavelength of 193 nm or less, and a total number of particles and pinholes having a diameter larger than 0.2 μm is 0.1 or less per square centimeter.    
     
     
         13 . The photo mask blank according to  claim 11  wherein said thin film for forming the pattern is a light semi-transmission film, and said photo mask blank is a halftone phase shift mask blank.  
     
     
         14 . The photo mask blank according to  claim 12  wherein said thin film for forming the pattern is a light semi-transmission film, and said photo mask blank is a halftone phase shift mask blank.  
     
     
         15 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 1 .  
     
     
         16 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 2 .  
     
     
         17 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 3 .  
     
     
         18 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 4 .  
     
     
         19 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 5 .  
     
     
         20 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 6 .  
     
     
         21 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 7 .  
     
     
         22 . A manufacturing apparatus of a photo mask blank for carrying out the manufacturing method according to  claim 8 .  
     
     
         23 . A photo mask manufactured by patterning a thin film in the photo mask blank according to  claim 9 .  
     
     
         24 . A photo mask manufactured by patterning a thin film in the photo mask blank according to  claim 10 .  
     
     
         25 . A photo mask manufactured by patterning a thin film in the photo mask blank according to  claim 13 .  
     
     
         26 . A photo mask manufactured by patterning a thin film in the photo mask blank according to  claim 14 .  
     
     
         27 . A pattern transfer method using the photo mask according to  claim 23  to transfer a pattern.