Sputtering target including magnetic field uniformity enhancing sputtering target backing tube
Certain example embodiments relate to sputtering target backing tube that are slightly ferromagnetic, thereby providing small-scale shunting that reduces the occurrence or magnitude of short-range magnetic field deviations during magnetron sputtering with cylindrical sputtering targets. For example, backing tube allows may be carefully optimized to be somewhat ferromagnetic, thereby enhancing the uniformity of the magnetic field generated by the magnet bar. In certain example embodiments, short range magnetic field deviations may be reduced to less than about 5% from average, more preferably less than about 2% from average, and still more preferably less than about 1% from average. Such short range magnetic field deviation reducing target backing tubes may be used in along with, or in place of, shims or shunts that address long range magnetic field deviations.
1 . A rotatable magnetron sputtering target, comprising:
a rotatable target tube comprising a target backing tube having sputtering material supported by an outer surface thereof to be sputter deposited on a substrate, the target backing tube being at least partially ferromagnetic; and
a magnet bar structure provided within the rotatable target tube, the magnet bar structure being stationary when the rotatable tube is rotating during sputtering,
wherein the target backing tube and the magnet bar structure are arranged to cooperate in producing a substantially uniform magnetic field during sputtering.
2 . The sputtering target of claim 1 , wherein the target backing tube has a magnetic permeability suitable for reducing short range deviations in the uniformity of the magnetic field created by the magnet bar structure.
3 . The sputtering target of claim 1 , wherein the target backing tube material is suitable for reducing short range magnetic field deviations to less than about 5% from the average magnetic field deviation.
4 . The sputtering target of claim 1 , wherein the target backing tube material is suitable for reducing short range magnetic field deviations to less than about 2% from the average magnetic field deviation.
5 . The sputtering target of claim 1 , wherein the target backing tube material is suitable for reducing short range magnetic field deviations to less than about 1% from the average magnetic field deviation.
6 . The sputtering target of claim 1 , wherein total magnetic field loss due to the ferromagnetic target backing tube material is less than about 20%.
7 . The sputtering target of claim 1 , wherein total magnetic field loss due to the ferromagnetic target backing tube material is less than about 10%.
8 . The sputtering target of claim 1 , further comprising at least one adjustment mechanism configured to alter a distance between at least a portion of the magnet bar structure and the sputtering material.
9 . The sputtering target of claim 8 , wherein the at least one adjustment mechanism comprises at least one shim and/or screw.
10 . The sputtering target of claim 2 , wherein the target backing tube material has a magnetic permeability suitable for adjusting the magnetic field uniformity within about 2 ft.
11 . The sputtering target of claim 2 , wherein the target backing tube material has a magnetic permeability suitable for adjusting the magnetic field uniformity within about 1 ft.
12 . The sputtering target of claim 1 , wherein the target backing tube comprises 400 series stainless steel.
13 . A rotatable magnetron sputtering target, comprising:
a rotatable target tube comprising a target backing tube having sputtering material supported by an outer surface thereof to be sputter deposited on a substrate, the target backing tube being at least partially ferromagnetic;
a magnet bar structure provided within the rotatable target tube, the magnet bar structure being stationary when the rotatable tube is rotating during sputtering; and
at least one adjustment mechanism configured to alter a distance between at least a portion of the magnet bar structure and the sputtering material,
wherein the at least one screw or shim adjustment mechanism and the magnet bar structure are arranged to cooperate during sputtering to (a) improve or increase long range magnetic field uniformity and (b) reduce long range magnetic field deviations,
wherein the target backing tube and the magnet bar structure are arranged to cooperate during sputtering to (a) improve or increase short range magnetic field uniformity and (b) reduce short range magnetic field deviations.
14 . The sputtering target of claim 13 , further comprising at least two screw or shim adjustment mechanisms provided on a single side of the magnet bar structure.
15 . The sputtering target of claim 14 , wherein a magnetic permeability of the target backing tube material is configured to reduce magnetic field deviations between adjacent ones of said adjustment mechanisms.
16 . The sputtering target of claim 13 , wherein the target backing tube material is configured to reduce magnetic field deviations along a length of less than about 2 feet.
17 . The sputtering target of claim 13 , wherein the target backing tube material is configured to reduce magnetic field deviations along a length of less than about 1 foot.
18 . The sputtering target of claim 13 , wherein the target backing tube material is suitable for reducing short range magnetic field deviations to less than about 2% from the average magnetic field deviation.
19 . The sputtering target of claim 13 , wherein the target backing tube material is suitable for reducing short range magnetic field deviations to less than about 1% from the average magnetic field deviation.
20 . The sputtering target of claim 13 , wherein the target backing tube comprises 400 series stainless steel.