Method for processing sputtering target and method for manufacturing sputtering target product

A method for processing a sputtering target comprising:

• processing a sputtering target by rotating a cutting tool which has a blade portion with an arc-shaped concave curved surface on a cross section along an axis, around the axis thereof, to chamfer the target at a corner portion between a sputtering surface and a side surface in the sputtering target with the arc-shaped concave curved surface of the blade portion in such a manner that the corner portion gets approximated to an arc-shaped aimed R face,
• wherein the sputtering target is chamfered at the corner portion in such a manner that both ends of the concave curved surface of the blade portion are positioned away from the sputtering target, and
• wherein, in a coordinate system in which a center point Cb of the aimed R face with the curvature radius Rb is set as an origin, a [mm] is a gap of a first center point C1 of the concave curved surface with the curvature radius Ra of the blade portion from the center point Cb in each of horizontal and vertical directions on the coordinate system, Ra, Rb, and a are set to satisfy the following conditions:
• with regard to an intercept L [mm] of an R face, the relationship of Rb/2≤L≤Rb is satisfied when L is represented by the formula of L=Rb−Ra{1−(Rb−a)2/Ra2}1/2−a;
• with regard to an angle θ [rad] formed between the sputtering surface of the sputtering target and an end portion of the R face of the sputtering target, the relationship of 0≤θ≤π/6 is satisfied when the angle θ [rad] is represented by the formula of θ=π/2−cos−1{1−(Rb−a)2/Ra2}1/2;
• and
• with regard to a distance d [mm] between an end portion of the concave curved surface of the blade portion and the sputtering surface of the sputtering target, the relationship of 0.05≤d is satisfied when the distance d [mm] is represented by the formula of d=Ra−Rb+a.

A method for processing a sputtering target, comprising:

• processing a disk-shaped or cylindrical sputtering target by rotating the target around a central axis thereof to chamfer the target at a corner portion between a sputtering surface and a side surface in the rotating sputtering target with an arc-shaped concave curved surface of a blade portion in such a manner that the corner portion gets approximated to an arc-shaped aimed R face,
• wherein the corner portion of the sputtering target is chamfered in such a manner that both ends of the concave curved surface of the blade portion were positioned away from the sputtering target, and
• wherein, in a coordinate system in which a center point Cb of the aimed R face with the curvature radius Rb is set as an origin, a [mm] is a gap of a first center point C1 of the concave curved surface with the curvature radius Ra of the blade portion from the center point Cb in each of horizontal and vertical directions on the coordinate system, Ra, Rb, and a are set to satisfy the following conditions:
• with regard to an intercept L [mm] of an R face, the relationship of Rb/2≤L≤Rb is satisfied when L is represented by the formula of L=Rb−Ra{1−(Rb−a)2/Ra2}1/2−a;
• with regard to an angle θ [rad] formed between the sputtering surface of the sputtering target and an end portion of the R face of the sputtering target, the relationship of 0≤θ≤π/6 is satisfied when the angle θ [rad] is represented by the formula of θ=π/2−cos−1{1−(Rb−a)2/Ra2}1/2;
• and
• with regard to a distance d [mm] between an end portion of the concave curved surface of the blade portion and the sputtering surface of the sputtering target, the relationship of 0.05≤d is satisfied when the distance d [mm] is represented by the formula of d=Ra−Rb+a.