Method for manufacturing a sputtering target structure
To provide a sputtering target structure which has good machinability and thermal conductivity and has good wettability with soldering materials, which is inexpensive and can be used repeatedly for a long period of time, and which is free from problems of cracking and peeling of the sputtering target therein, a sputtering target structure is formed by bonding a sputtering target and a backing plate. The backing plate is formed of a material that has the difference in the linear expansion coefficient between it and the sputtering target material of at most 2×10 −6 /K, and a copper plate having a thickness of from 0.3 to 1.5 mm is disposed on at lest one face of the backing plate.
1. A method for manufacturing a sputtering target structure by bonding a sputtering target and a backing plate, wherein the backing plate is formed of a material that has a linear expansion coefficient different from that of the sputtering target material by at most 2×10 −6 /K, wherein a copper plate having a thickness of from 0.3 to 1.5 mm is disposed on at least one face of the backing plate, and wherein the backing plate has a cooling channel made of copper or stainless steel pipes running therethrough, the method comprising:
forming the backing plate by subjecting a mold containing copper or stainless steel pipes and a reinforcing material to heat treatment to obtain a sintered body of the reinforcing material integrally formed with a cooling channel made of the pipes running therethrough, fitting a copper plate to the sintered body of the reinforcing material, putting the sintered body of the reinforcing material with the copper plate fitted thereto in a pressure casting mold, and casting aluminum melt into the mold followed by solidification under pressure; and boding the sputtering target to the formed backing plate.
2. The method for manufacturing a sputtering target structure as claimed in claim 1 , wherein a material constituting the backing plate is a composite material that comprises aluminum or aluminum alloy as the matrix and, as incorporated therein, one or more granular or fibrous reinforcing materials selected from a group consisting of carbon, silicon carbide, alumina, silicon nitride, mullite and aluminum borate, and the material has a linear expansion coefficient of from 3.5 to 17×10 −6 /K.
3. The method for manufacturing a sputtering target structure as claimed in claim 1 , wherein the sputtering target and the backing plate are bonded together with indium, tin or their alloy.