ROTARY SPUTTERING TARGET AND APPARATUS FOR MANUFACTURE
The process that is the subject of this invention is a method of making a rotary sputtering target having the steps of providing a cylinder of sputtering target material having an adhesion-wetting layer on its inside surface; providing a stainless steel sputtering target backing tube having an outside diameter smaller than the sputtering target material inside diameter, the backing tube having an adhesion-wetting layer on its outside surface; welding an upper and lower stainless steel retaining ring to the backing tube adjacent to the sputtering target material so that the target material is in compression and the backing tube in tension; and introducing molten bonding material into the annulus between the backing tube and the sputtering target material. The apparatus that is the subject of the present invention is a rotary sputtering target apparatus having a cylinder of sputtering target material; a backing tube having a smaller outside diameter than the inside diameter of the sputtering target material; and bonding material disposed between the target material and backing tube, the bonding material bonding them together.
1 . A rotary sputtering target apparatus comprising:
a backing tube having an outside diameter smaller than a sputtering target material inside diameter;
at least one cylinder of sputtering target material coaxially stacked onto the backing tube, the tube occupying the center of the individual cylinder; and
bonding material in an annulus between the backing tube and the sputtering target material.
2 . The apparatus of claim 1 , the target material cylinders having an adhesion-wetting layer on its inside surface.
3 . The apparatus of claim 1 , the backing tube having an adhesion-wetting layer on its outside surface.
4 . The apparatus of claim 2 , wherein the adhesion-wetting layer is applied by vacuum deposition onto the sputtering target material inside surface.
5 . The apparatus of claim 3 , wherein the adhesion-wetting layer is applied by vacuum deposition onto the sputtering target material outside surface.
6 . The apparatus of claim 1 with the backing tube is in tension and the target material stack is in compression.
7 . The apparatus of claim 1 further comprising:
an upper retaining ring secured on one end of the backing tube and adjacent to the sputtering target material; and
a lower retaining ring secured on an end of the backing tube opposite the upper retaining ring and adjacent to the sputtering target material.
8 . The apparatus of claim 7 , wherein the upper and lower retaining rings are made of stainless steel.
9 . The apparatus of claim 1 , wherein the backing tube is made of stainless steel.
10 . An apparatus for making a rotary sputtering target comprising:
a backing tube having an outside diameter smaller than a sputtering target material inside diameter;
at least one cylinder of sputtering target material and up to multiple cylindrical segments of target material stacked upon one another coaxially stacked onto the backing tube, the tube occupying the center of the cylinder; and
bonding material disposed in the annulus between the backing tube and the sputtering target material.
11 . The apparatus of claim 10 with the backing tube in tension and the target material stack in compression.
12 . The apparatus of claim 10 further comprising:
an upper retaining ring secured on one end of the backing tube and adjacent to the sputtering target material; and
a lower retaining ring secured on an end of the backing tube opposite the upper retaining ring and adjacent to the sputtering target material.
13 . The apparatus of claim 12 , wherein the upper and lower retaining rings are made of stainless steel.
14 . The apparatus of claim 10 , wherein the backing tube is made of stainless steel.
15 . The apparatus of claim 10 further comprising:
a top ring insert disposed between the backing tube and a mold pipe above the upper retaining ring; and
a bottom ring insert disposed between the backing tube and a mold pipe below the lower retaining ring.
16 . The apparatus of claim 15 further comprising a vacuum port enabling the inner volume of the mold pipe to be under vacuum during the pouring of the molten bonding material into the annulus between the backing tube and target material.