Sputtering Cathode, Sputtering Cathode Assembly, and Sputtering Apparatus

Abstract

The sputtering cathode has a tubular shape having a pair of long sides facing each other in cross-sectional shape, has a sputtering target whose erosion surface faces inward, and a magnetic circuit is provided along the sputtering target. The pair of long sides are constituted by rotary targets each having a cylindrical shape. The rotary target is internally provided with a magnetic circuit and configured to allow the flow of cooling water. The magnetic circuit is provided parallel to the central axis of the rotary target and has a rectangular cross-sectional shape having a long side perpendicular to the radial direction of the rotary target.

We claim the following: 
     
         1 . A sputtering device, comprising:
 a plurality of sputtering cathodes, each of which comprises
 a hollow sputtering target with a rectangular interior region and having a rectangular tubular configuration that extends in a lengthwise direction with a rectangular cross-section taken transverse to the lengthwise direction, the sputtering target having an open end at each end thereof and comprising a) a pair of major side walls that extend in the lengthwise direction of the sputtering target and that oppose each other across the rectangular interior region of the sputtering target, with opposing inner surfaces of the major side walls constituting sputtering erosion surfaces; and b) a pair of short side walls that extend in the lengthwise direction of the sputtering target and that oppose each other across the rectangular interior region of the sputtering target, the pair of short side walls connecting the pair of major side walls such that the rectangular interior region of the sputtering target is bounded by and delimited by the pair of major side walls along long sides thereof and by the pair of short side walls along short sides thereof; 
 a magnetic field-generating assembly consisting of a pair of permanent-magnet units disposed near outer surfaces of each of the major side walls of the sputtering target with one permanent-magnet unit disposed toward each open end of the sputtering target in a permanent-magnet arrangement and with each of the permanent-magnet units having a north pole and a south pole, the permanent-magnet arrangement of the magnetic field-generating assembly being defined by 1) the north pole of a first permanent-magnet unit of the pair of permanent-magnet units facing toward the sputtering target and the south pole of said first permanent-magnet unit of the pair of permanent-magnet units facing away from the sputtering target and constituting a first away-facing pole; and 2) the south pole of a second permanent-magnet unit of the pair of permanent-magnet units facing toward the sputtering target and the north pole of said second permanent-magnet unit of the pair of permanent-magnet units facing away from the sputtering target and constituting a second away-facing pole; and 
 a magnetically conductive yoke extending between and magnetically connecting the first and second away-facing poles of the first and second permanent-magnet units, respectively; 
 whereby the major side walls of the sputtering target, the pair of permanent-magnet units, and the magnetically conductive yoke form a magnetic circuit along which magnetic flux circulates in a flux circulation direction extending 1) from the north pole of said first permanent-magnet unit of the pair of permanent-magnet units along longitudinally central portions of the major side walls of the sputtering target to the south pole of said second permanent-magnet unit of the pair of permanent-magnet units; 2) along said second permanent-magnet unit of the pair of permanent-magnet units from the south pole thereof to the north pole thereof; 3) along the magnetically conductive yoke from the north pole of said second permanent-magnet unit of the pair of permanent-magnet units to the south pole of said first permanent-magnet unit of the pair of permanent-magnet units; and 4) along said first permanent-magnet unit of the pair of permanent-magnet units from the south pole thereof to the north pole thereof; 
 the plurality of sputtering cathodes being arranged adjacent to each other and side-by-side aligned with each other with the lengthwise directions of the sputtering cathodes being parallel to each other and with the major side walls of the sputtering cathodes being parallel to each other, with the permanent-magnet arrangements of the pairs of permanent-magnet units of adjacent sputtering cathodes being opposite to each other whereby the flux circulation directions associated with adjacent sputtering cathodes are opposite to each other; and 
   a first anode disposed near a first one of the open ends of each of the sputtering targets, which first open end is to be disposed distally relative to a substrate on which sputtering-based film formation is to be performed.   
     
     
         2 . The sputtering device according to  claim 1 , further comprising a light-blocking shield disposed near a second one of the open ends of each of the sputtering targets, which second open end is to be disposed proximally relative to the substrate on which sputtering-based film formation is to be performed. 
     
     
         3 . The sputtering device according to  claim 2 , wherein the light-blocking shields are electrically connected to the first anodes such that the light-blocking shields constitute second anodes. 
     
     
         4 . The sputtering device according to  claim 1 , further comprising an auxiliary magnetic pole disposed near a second one of the open ends of each of the sputtering targets, which second open end is to be disposed proximally relative to the substrate on which sputtering-based film formation is to be performed. 
     
     
         5 . The sputtering device according to  claim 1 , further comprising a light-blocking shield disposed near a second one of the open ends of each of the sputtering targets, which second open end is to be disposed proximally relative to the substrate on which sputtering-based film formation is to be performed; and
 an auxiliary magnetic pole disposed near the second one of the open ends of each of the sputtering targets.   
     
     
         6 . The sputtering device according to  claim 5 , wherein the auxiliary magnetic poles are disposed between the light-blocking shields and respective ones of the sputtering targets. 
     
     
         7 . The sputtering device according to  claim 5 , wherein the light-blocking shields are electrically connected to the first anodes such that the light-blocking shields constitute second anodes.