Sputtering target having increased power compatibility
A plate-centering system that has a plate with a holder, in which the plate is centered in the holder both at room temperature and at higher temperatures, independently of the thermal expansion of the plate and the holder, and the plate can freely expand in the holder at higher temperatures. The invention relates in particular to a target having a frame-shaped target mount, which is very well suited for use in a coating source for high power pulsed magnetron sputtering of the target.
1. A coating source as a material supply for a PVD coating, comprising:
a) a plate supported in a holder, the plate having a plate front, a plate back, and a centering device; the holder having a frame-shaped target mount for accommodating the plate while the plate is a target; the plate front is provided for converting coating material from a surface into a gas phase during a PVD process and the centering device assures centering of the plate at different plate temperatures; and
b) a cooling device, which is provided on a back of the plate and is equipped with a cooling conduit and a closed cooling plate that is embodied in the form of a movable diaphragm; in order to ensure a thermal contact between the back of the plate and the diaphragm, a self-adhesive graphite film is glued to the back of the plate,
wherein elements of a bayonet fitting are provided on the holder and the cooling device so that the holder with the centered plate can be affixed to the cooling device by the bayonet fitting, and wherein in order to hold the target at least three guide protrusions and/or grooves spaced apart from another are provided in the target and the target mount so that the guide protrusions of the target and/or the target mount are held in the corresponding grooves of the target mount and/or the target when the target is attached to the target mount; and the sets of guide protrusions and grooves are distributed so that in each guide protrusion and groove set a position of a center of a width of the groove coincides with a position of a center of a width of a corresponding guide protrusion and this position is selected so that at room temperature the position is situated in an axial direction from the target center, which remains unchanged in the same axial direction from the target center after a thermal expansion of the target and/or the target mount at an increased temperature; and wherein a material of the plate has a first thermal expansion coefficient α 1 and a material of the holder has a second thermal expansion coefficient α 2 , where: α 1 >α 2 .
2. The coating source according to claim 1 , wherein in an edge region of the hack of the plate, the holder has a supporting surface for flat support of the plate and above the plate front, the holder has a flute so that after the plate is inserted into the holder, the latter can be affixed there by a snap ring, which snaps into the flute.
3. The coating source according to claim 1 , wherein the holder consists essentially of a temperature-stable, nonmagnetic steel, which is forged and solution annealed at 1020° C. for one hour.
4. The coating source according to claim 1 , wherein the coating source can be connected to a voltage source, which make it possible to apply a negative potential to a target relative to an electrode so that the target can be used as a cathode and the electrode can be used as an anode.
5. The coating source according to claim 4 , wherein the anode is placed around the target and is an anode ring.
6. A PVD system with at least one coating source according to claim 1 .