Sputtering target-backing plate assembly and method for producing same
Provided is a sputtering target-backing plate assembly wherein a Cu—Cr alloy backing plate is bonded to a Ti target via a layer of a strain absorbing material placed at an interface between the Ti target and the Cu—Cr alloy backing plate. In particular, the present invention relates to a sputtering target-backing plate assembly and a production method thereof, the assembly being capable of absorbing strain at the interface between the target and the backing plate in order to prevent deformation (displacement) during sputtering. An object of the present invention is to solve a problem inherent to Titanium (Ti) and a problem in selecting a backing plate compatible with it.
1. A sputtering target-backing plate assembly, wherein a Cu—Cr alloy backing plate having a content of Cr of 0.7 to 1.2 wt % is bonded to a Ti target via a layer of a strain absorbing material which is placed at an interface between the Ti target and the Cu—Cr alloy backing plate, the layer of the strain absorbing material being Al or an alloy containing Al as a primary component thereof and having a thickness of 1 to 6 mm and having a bond strength of 3 kg/mm2 or more.
2. The sputtering target-backing plate assembly according to claim 1 , wherein a difference between a maximum value of displacement from a flat when turning sputtering ON and a maximum value of displacement from a flat when turning sputtering OFF is 1 mm or less.
3. The sputtering target-backing plate assembly according to claim 2 , wherein a surface of the Cu—Cr alloy backing plate is roughened with a lathe in advance before bonding.
4. The sputtering target-backing plate assembly according to claim 3 , wherein the Ti target is a high-purity Ti having a purity of 4N5 or higher.
5. The sputtering target-backing plate assembly according to claim 1 , wherein a surface of the Cu—Cr alloy backing plate is roughened with a lathe before bonded to the Ti target.
6. The sputtering target-backing plate assembly according to claim 1 , wherein the Ti target is a high-purity Ti having a purity of 4N5 or more.
7. The sputtering target-backing plate assembly according to claim 1 , wherein the Cu—Cr alloy backing plate is diffusion-bonded to the Ti target via the layer of the strain absorbing material.
8. A method for producing a sputtering target-backing plate assembly in which a Ti target is bonded to a Cu—Cr alloy backing plate having a content of Cr of 0.7 to 1.2 wt %, the method comprising the steps of: placing a layer of Al or an alloy primarily containing Al, which has a thickness of 1 mm or more and 6 mm or less, at the interface between the target material and the backing plate; and performing bonding at a temperature between 400 and 550° C. under a pressure of 1450 kg/cm 2 to obtain a sputtering target-backing plate assembly having a bonding strength of 3 kg/mm 2 or more.
9. The method according to claim 8 , wherein said bonding step is a diffusion-bonding step.