A kind of diffusion welding method of high-purity copper target

Abstract

The invention provides a method for diffusion welding of a high-purity copper target. The diffusion welding method includes the following steps: preparing a high-purity copper target and a back plate, and processing threads on the welding surface of the back plate; on the threaded surface of the back plate; combine the high-purity copper target with the back plate and put it into the metal sheath, then degas the metal sheath, and then seal the degassed metal sheath; hot isostatic Press the sealed metal sheath, and then cool it to room temperature; remove the metal sheath, and complete the diffusion welding of the high-purity copper target and the back plate. The invention evenly arranges the metal powder on the welding surface, sinters the metal powder in the hot isostatic pressing process, and fills the problem of holes caused by thread extrusion deformation, thereby improving the bond between the high-purity copper target and the back plate The combination rate ensures the electrical and thermal conductivity of the target components during magnetron sputtering.

Description

technical field [0001] The invention belongs to the technical field of semiconductors, and relates to a diffusion welding method of a target, in particular to a diffusion welding method of a high-purity copper target. Background technique [0002] The sputtering target is an extremely important key material necessary for the manufacture of semiconductor chips. The principle of using it to make devices is to use physical vapor deposition technology to bombard the target with high-pressure accelerated gaseous ions, so that the atoms of the target are sputtered out. , deposited on the silicon wafer in the form of a thin film, and finally form the complex wiring structure in the semiconductor chip. [0003] Sputtering targets have many advantages such as uniformity and controllability of metal coatings, and are widely used in the semiconductor field. Because copper has higher electrical conductivity and better anti-electromigration properties, copper targets are widely used in ...

AI Technical Summary

Problems solved by technology

[0009] However, the high-purity copper target needs to be welded with the back plate during magnetron sputtering, and the recrystallization temperature of the high-purity copper target is very low. During the welding process, in order to prevent the grain abnormality of the high-purity copper target When growing up, the welding temperature needs to be controlled in a lower range, generally not exceeding 350°C. At this time, the high-purity copper target and the back plate are maintained at a relatively high hardness. The tip of the thread is extruded and deformed, it is difficult to embed into the high-purity copper target, and eventually holes are formed at the tip of the thread, which reduces the contact area of ​​the welding surface, reduces the welding strength, and affects the overall electrical and thermal conductivity of the target when used performance is adversely affected

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