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).

1 - 27 . (canceled)  
     
     
         28 . A manufacturing method for a photo mask comprising preparing a photo mask blank having a thin film on a transparent substrate and forming a pattern on the thin film, which preparing comprising: 
 directing the surface of a target downwards and the surface of the 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 to form said thin film.    
     
     
         29 . A manufacturing method of a photo mask comprising preparing a photo mask blank having a thin film on a transparent substrate and forming a pattern on the thin film, which preparing comprising: 
 forming said thin film using a DC magnetron sputtering apparatus comprising at least a sputtering target, a magnetron cathode to which the target is attached, 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.    
     
     
         30 . The manufacturing method according to  claim 29  wherein 
 a whole-surface erosion cathode is applied,    non-sputtered area on the target is shielded, or    surface of the non-sputtered portion on the target is roughened    as said mechanism for reducing film formation on the non-sputtered area on the target.    
     
     
         31 . The manufacturing method according to  claim 30  wherein a comer of the target is formed into a rounded surface or an end surface of the target is roughened as said mechanism for reducing film formation on the non-sputtered area on the target.  
     
     
         32 . The manufacturing method according to  claim 29  wherein the mechanism for reducing 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 rate value t according to the formula (i) for a position on the shield is not larger than the value for a position on the substrate;        t= cos θ 1 ×sin(θ 1 −θ 2 )/ r   2   (i)    whereby r denotes a distance between a center of the target and the position,    θ 1  denotes an angle of a line connecting the center of the target to the position with respect to a normal of a target plane,    θ 2  denotes an angle of a plane on which the position is located with respect to the normal of the target plane, and    t denotes the relative film formation rate for the position defined by r and θ 1 .    
     
     
         33 . The manufacturing method according to  claim 32  wherein 
 a comer of the shield is rounded,    a surface of the shield is roughened, or    an end of the shield is placed above the target plane as the mechanism for reducing film formation on said shield surface.    
     
     
         34 . The manufacturing method according to  claim 29  wherein the apparatus further comprises a backing plate for supporting the target, and the surface of the backing plate is roughened.  
     
     
         35 . The manufacturing method according to  claim 29  wherein the apparatus further comprises a shield plate for preventing the film from being formed on a peripheral portion of the substrate.  
     
     
         36 . The manufacturing method according to  claim 29  wherein the prepared photo mask blank is such that 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.  
     
     
         37 . The manufacturing method according to  claim 29 , an exposure wavelength for said mask having a center wavelength of 193 nm or less, wherein the prepared photo mask blank is such that and a total number of particles and pinholes having a diameter larger than 0.2 μm is 0.1 or less per square centimeter.  
     
     
         38 . The manufacturing method according to  claim 36  wherein said thin film is a light semi-transmission film, and said photo mask is a halftone phase shift mask.  
     
     
         39 . The manufacturing method according to  claim 37  wherein said thin film is a light semi-transmission film, and said photo mask blank is a halftone phase shift mask blank.