A RAMO.sub.4 substrate is formed from single crystal represented by a formula of RAMO.sub.4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected form a group consisting of Hg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on at least one surface of the RAMO.sub.4 substrate. The epitaxially-grown surface includes a plurality of cleavage surfaces which are regularly distributed, and are separated from each other.

A RAMO.sub.4 substrate includes a single crystal represented by a formula of RAMO.sub.4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected from a group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on one surface of the RAMO.sub.4 substrate, a satin-finish surface is provided on another surface. The satin-finish surface has surface roughness which is larger than that of the epitaxially-grown surface.

A RAMO.sub.4 substrate includes a single crystal represented by a formula of RAMO.sub.4 (in the formula, R indicates one or a plurality of trivalent elements selected from a group consisting of Sc, In, Y, and a lanthanoid element, A indicates one or a plurality of trivalent elements selected from a group consisting of Fe(III), Ga, and Al, and M indicates one or a plurality of bivalent elements selected from a group consisting of Mg, Mn, Fe(II), Co, Cu, Zn, and Cd). An epitaxially-grown surface is provided on one surface of the RAMO.sub.4 substrate, a satin-finish surface is provided on another surface. The satin-finish surface has surface roughness which is larger than that of the epitaxially-grown surface.

The present invention provides a process for the removal of chromium contaminants on a spent ruthenium sputtering target used in Plasma Vapor Deposition by the steps of grit abrasion, organic solvent cleaning, and being subjected to an electric field in an acidic bath including a surfactant, and followed by subsequent water and air rinse and further grit abrasion. Removal of the contaminants is verified by spectroscopy.

The present invention provides a process for the removal of chromium contaminants on a spent ruthenium sputtering target used in Plasma Vapor Deposition by the steps of grit abrasion, organic solvent cleaning, and being subjected to an electric field in an acidic bath including a surfactant, and followed by subsequent water and air rinse and further grit abrasion. Removal of the contaminants is verified by spectroscopy.

Disclosed is a wafer polishing apparatus including a base, a lower surface plate disposed on the upper surface of the base, an upper surface plate disposed on the lower surface plate and a first shape adjustment unit configured to deform the shape of the lower surface of the upper surface plate so that the lower surface of the upper surface plate has one of a concave shape, a flat shape and a convex shape in a first direction, and the first direction is a direction from the lower surface plate to the upper surface plate.

A method for smoothing and/or polishing slabs of stone or stone-like material suitable for being implemented with a machine comprising: a support bench (16) for a slab to be machined; and at least one machining station (14). The machining station comprises two bridge support structures (20, 22) arranged transversely astride the support bench (16). A spindle-carrying beam (24), in suitable for being moved above the bridge structures in a transverse direction, is provided on the bridge support structures (20, 22). At least one spindle-carrying structure (34), suitable for being rotated about its own vertical axis (32), is provided on the spindle-carrying beam (24). Each spindle-carrying structure (34) is provided with two motorized spindles (38A, 38B), the ends of which are provided with machining heads (42A, 42B) arranged spaced apart and opposite each other with respect to the vertical axis (32) of the spindle-carrying structure (34) and comprising machining tools (44A, 44B). The machine comprises a programmable computerized unit for controlling the position, movement and speed of the moving members. The method is characterized in that:—the beam and the spindle-carrying structures move coordinated and synchronized with each other;—for each stroke of the beam (24) in the transverse direction, each spindle-carrying structure performs a rotation of 180° about its axis of rotation (32);—when the beam (24) is located at the centre line of the bench (16), the axis (60) connecting the rotation axes of the spindles (38A, 38B) is perpendicular to the longitudinal direction of the machine; and—when the beam (24) is located at the maximum distance from the centre line of the bench (16), the axis (60) is parallel to the longitudinal axis of the machine.

A method for smoothing and/or polishing slabs of stone or stone-like material suitable for being implemented with a machine comprising: a support bench (16) for a slab to be machined; and at least one machining station (14). The machining station comprises two bridge support structures (20, 22) arranged transversely astride the support bench (16). A spindle-carrying beam (24), in suitable for being moved above the bridge structures in a transverse direction, is provided on the bridge support structures (20, 22). At least one spindle-carrying structure (34), suitable for being rotated about its own vertical axis (32), is provided on the spindle-carrying beam (24). Each spindle-carrying structure (34) is provided with two motorized spindles (38A, 38B), the ends of which are provided with machining heads (42A, 42B) arranged spaced apart and opposite each other with respect to the vertical axis (32) of the spindle-carrying structure (34) and comprising machining tools (44A, 44B). The machine comprises a programmable computerized unit for controlling the position, movement and speed of the moving members. The method is characterized in that:—the beam and the spindle-carrying structures move coordinated and synchronized with each other;—for each stroke of the beam (24) in the transverse direction, each spindle-carrying structure performs a rotation of 180° about its axis of rotation (32);—when the beam (24) is located at the centre line of the bench (16), the axis (60) connecting the rotation axes of the spindles (38A, 38B) is perpendicular to the longitudinal direction of the machine; and—when the beam (24) is located at the maximum distance from the centre line of the bench (16), the axis (60) is parallel to the longitudinal axis of the machine.

A processing method for a wafer having a chamfered portion at a peripheral edge includes a holding step of holding the wafer by a holding table, and a chamfer removing step of rotating the holding table while causing a first cutting blade to cut into the peripheral edge of the wafer while supplying a cutting liquid from a first cutting liquid supply nozzle to cut the peripheral edge of the wafer. In the chamfer removing step, a second cutting unit is positioned at a position adjacent to the first cutting unit at such a height that a second cutting blade does not make contact with the wafer and on the side of the center of the wafer as compared to the first cutting unit, and the cutting liquid is supplied from a second cutting liquid supply nozzle.

A polishing method which can remove foreign matters from an entire back surface of a substrate at a high removal rate is provided. The polishing method includes placing a polishing tool in sliding contact with an outer circumferential region of a back surface of a substrate while holding a center-side region of the back surface of the substrate, and placing a polishing tool in sliding contact with the center-side region of the back surface of the substrate while holding a bevel portion of the substrate to polish the back surface in its entirety.