Cylindrical sputtering target and process for producing the same

Abstract

Provided is a cylindrical ceramic sputtering target, which significantly reduces the occurrence of a crack, a chip, extraordinary discharge and a nodule. By filling a molten bonding material in a cavity defined by a cylindrical ceramic target material and a cylindrical base material, starting cooling the molten bonding material from its one end toward its other end in a cylindrical axial direction in sequence, and further filling the molten bonding material in the cavity during cooling, a cylindrical ceramic sputtering target is manufactured so as to be characterized in that as observed by an X-ray radiograph of the bonding material, the total area of portions where no bonding material exists is 10 cm 2 or less per 50 cm 2 of X-ray radiograph area, and the maximum area of the portions where no bonding material exists is 9 cm 2 or less.

1 . A cylindrical ceramic sputtering target comprising a bonding material filled in a cavity defined by a cylindrical ceramic target material and a cylindrical base material,
 wherein as observed by an X-ray radiograph of the bonding material, the total area of portions where no bonding material exists is 10 cm 2  or less per 50 cm 2  of X-ray radiograph area, and the maximum area of the portions where no bonding material exists is 9 cm 2  or less and wherein the volume ratio of the bonding material at 25° C. that is filled in the cavity is at least 96.8% with respect to the volume of the cavity at the melting point of the bonding material.   
     
     
         2 . (canceled) 
     
     
         3 . The target according to  claim 2 , wherein the volume ratio is at least 98%. 
     
     
         4 . The target according to  claim 2 , wherein the volume ratio is at least 100%. 
     
     
         5 . The target according to  claim 1 , wherein the bonding material is In, an In alloy, Sn or a Sn alloy. 
     
     
         6 . The target according to  claim 1 , wherein the cylindrical ceramic target material comprises ITO or AZO. 
     
     
         7 . A process for producing the target recited in  claim 1 , comprising filling a molten bonding material in a cavity, starting cooling the molten bonding material from its one end toward its other end in a cylindrical axial direction in sequence, and further filling the molten bonding material in the cavity during cooling. 
     
     
         8 . The method according to  claim 7 , further comprising supplying the molten boding material from an end opposite the one end in the cylindrical axial direction where cooling starts. 
     
     
         9 . The method according to  claim 7 , further comprising filling the molten bonding material by supplying, during cooling, the molten bonding material from a bonding material supply portion to store the molten bonding material. 
     
     
         10 . The method according to  claim 7 , further comprising vibrating the molten bonding material filled in the cavity when or after filling the boding material in the cavity.