Molybdenum sputtering target assembly and method of making

1 . A molybdenum sputtering target assembly comprising:

a molybdenum sputtering target consisting of molybdenum and having a thickness of about 0.2 inches and about 0.6 inches; and

a molybdenum backing plate consisting of molybdenum or a molybdenum alloy, the molybdenum backing plate immediately adjacent to and diffusion bonded directly to the molybdenum sputtering target, wherein the molybdenum sputtering target has an average grain size of less than about 50 μm and wherein the grain size differs by not more than +/−5 μm through the thickness of the molybdenum sputtering target.

2 . The molybdenum sputtering target assembly of claim 1 , wherein the molybdenum alloy is selected from the group consisting of titanium-zirconium-molybdenum alloy, molybdenum tungsten alloy, molybdenum copper alloy, and molybdenum hafnium carbon alloy.

3 . The molybdenum sputtering target assembly of claim 1 , wherein the molybdenum backing plate consists of molybdenum having a lower purity than the molybdenum of the molybdenum sputtering target.

4 . The molybdenum sputtering target assembly of claim 1 , wherein the molybdenum sputtering target is between about 0.2 inches and about 0.6 inches in thickness.

5 . A method for forming a sputtering target assembly, the method comprising:

positioning a molybdenum sputtering target immediately adjacent to a molybdenum backing plate; and

diffusion bonding the molybdenum sputtering target directly to the molybdenum backing plate by hot isostatic pressing at a pressure equal to or greater than 15 ksi and a temperature of from about 700° C. and about 1500° C.,

wherein the molybdenum sputtering target consists of molybdenum and has a thickness of about 0.2 inches and about 0.6 inches, and

wherein the molybdenum backing plate consists of molybdenum or a molybdenum alloy and

wherein after the diffusion bonding, the molybdenum sputtering target has an average grain size of less than about 50 μm and wherein the grain size differs by +/−5 μm through the thickness of the molybdenum sputtering target.

6 . The method of claim 5 , wherein the molybdenum alloy is selected from the group consisting of titanium-zirconium-molybdenum Alloy, molybdenum tungsten alloy, molybdenum copper alloy, and molybdenum hafnium carbon alloy).

7 . The method of claim 5 wherein the molybdenum backing plate consists of molybdenum having a lower purity than the molybdenum of the molybdenum sputtering target.

8 . The method of claim 5 , wherein after the hot isostatic pressing, the molybdenum sputtering target has an average grain size of less than about 100 μm.

9 . The method of claim 5 , wherein after the hot isostatic pressing, the grain size differs by +/−5 μm through the thickness of the molybdenum sputtering target.

10 . The method of claim 5 , wherein after the hot isostatic pressing, the molybdenum sputtering target has an average grain size of less than about 50 μm.