An inner-periphery-side cutoff part where a polishing surface of an upper plate inclines upward toward an inner periphery part of the upper plate and an inner-periphery-side cutoff part where a polishing surface of a lower plate inclines downward toward an inner periphery part of the lower plate are respectively formed on the respective inner periphery parts of the upper plate and the lower plate, or an outer-periphery-side cutoff part where the polishing surface of the upper plate inclines upward toward an outer periphery part of the upper plate and an outer-periphery-side cutoff part where the polishing surface of the lower plate inclines downward toward an outer periphery part of the lower plate are respectively formed on the respective outer periphery parts of the upper plate and the lower plate, or all of them are formed thereon.

A workpiece processing method includes a resin coating step of coating a resin on a front surface of a workpiece, a resin curing step of applying an ultraviolet ray to the coated resin to be cured, a resin grinding step of grinding the cured resin with grinding stones to be flattened, and a workpiece grinding step of holding the flattened resin side of the workpiece on a chuck table and grinding the back surface of the workpiece with grinding stones. In the resin grinding step, grinding is performed while cleaning the resin stuck to the grinding stones. Accordingly, it is possible to grind the resin coated on the front surface of the workpiece and the back surface of the workpiece in the same apparatus.

A workpiece processing method includes a resin coating step of coating a resin on a front surface of a workpiece, a resin curing step of applying an ultraviolet ray to the coated resin to be cured, a resin grinding step of grinding the cured resin with grinding stones to be flattened, and a workpiece grinding step of holding the flattened resin side of the workpiece on a chuck table and grinding the back surface of the workpiece with grinding stones. In the resin grinding step, grinding is performed while cleaning the resin stuck to the grinding stones. Accordingly, it is possible to grind the resin coated on the front surface of the workpiece and the back surface of the workpiece in the same apparatus.

A workpiece processing apparatus including: a center drum that is rotatable around a rotation axis and has at least one first groove formed in the axial direction on the peripheral surface, a carrier having a holding hole to insert and hold a workpiece to be processed, an upper and lower turn table that are rotatable around the rotation axis in a state wherein the carrier holding workpiece is interposed, at least one hook fitted in the upper turn table's internal circumference, with the tip being inserted into the first groove and movable along first groove; wherein the center drum has at least one second groove formed in the axial direction on peripheral surface, and second groove has a length different from that of the first groove and has a supporting surface to support the hook from below at a position above a position where upper turn table processes the workpiece.

A workpiece processing apparatus including: a center drum that is rotatable around a rotation axis and has at least one first groove formed in the axial direction on the peripheral surface, a carrier having a holding hole to insert and hold a workpiece to be processed, an upper and lower turn table that are rotatable around the rotation axis in a state wherein the carrier holding workpiece is interposed, at least one hook fitted in the upper turn table's internal circumference, with the tip being inserted into the first groove and movable along first groove; wherein the center drum has at least one second groove formed in the axial direction on peripheral surface, and second groove has a length different from that of the first groove and has a supporting surface to support the hook from below at a position above a position where upper turn table processes the workpiece.

A workpiece processing apparatus which coats a front surface of a workpiece with a resin, the workpiece having devices formed in regions demarcated by a plurality of planned dividing lines formed in a lattice manner. The workpiece processing apparatus includes a cassette mounting base mounted with a cassette housing a plurality of workpieces, a resin coating unit that coats the front surface of the workpiece with the resin, a resin curing unit that cures the resin by applying an external stimulus to the coated resin, a resin grinding unit that flattens the cured resin by grinding the cured resin by a rotating grinding stone, and a conveying mechanism that conveys the workpiece between the units.

The present invention provides: an InP wafer optimized from the viewpoint of small edge roll-off (ERO) and sufficiently high flatness even in the vicinity of a wafer edge; and a method for effectively producing the InP wafer. The InP wafer having a roll-off value (ROA) of from 1.0 m to 1.0 m is obtained by using a method including: performing a first stage polishing under a processing pressure of from 10 to 200 g/cm.sup.2 for a processing time of from 0.1 to 5 minutes, while supplying a polishing solution containing bromine to at least one side of an InP single crystal substrate that will form the InP wafer; and performing a second stage polishing under a processing pressure of from 200 to 500 g/cm.sup.2 for a processing time of from 0.5 to 10 minutes, provided that the processing pressure is higher than that of the first stage polishing by 50 g/cm.sup.2 or higher.

The present invention provides: an InP wafer optimized from the viewpoint of small edge roll-off (ERO) and sufficiently high flatness even in the vicinity of a wafer edge; and a method for effectively producing the InP wafer. The InP wafer having a roll-off value (ROA) of from 1.0 m to 1.0 m is obtained by using a method including: performing a first stage polishing under a processing pressure of from 10 to 200 g/cm.sup.2 for a processing time of from 0.1 to 5 minutes, while supplying a polishing solution containing bromine to at least one side of an InP single crystal substrate that will form the InP wafer; and performing a second stage polishing under a processing pressure of from 200 to 500 g/cm.sup.2 for a processing time of from 0.5 to 10 minutes, provided that the processing pressure is higher than that of the first stage polishing by 50 g/cm.sup.2 or higher.

Provided is a method of lapping a semiconductor wafer, which can suppress the formation of a ring-shaped pattern in a nanotopography map. The method of lapping a semiconductor wafer includes: a stopping step of stopping lapping of a semiconductor wafer; a reversing step of reversing surfaces of the semiconductor wafer facing a upper plate and a lower plate after the stopping step; and a resuming step of resuming lapping of the semiconductor wafer after the reversing step while maintaining the reversal of the surfaces facing the plates.

A method for raising a polishing pad for polishing a silicon wafer, wherein a polishing pad made of foamed urethane resin is attached to a polishing machine, after dressing is performed, dummy polishing is performed, after processing to remove the polishing residues that have built up in the polishing pad by the dummy polishing is then performed, an amount of polishing residues in the polishing pad is measured, and a rise of the polishing pad subjected to the dummy polishing is judged based on the measured amount of polishing residues. As a result, a method for raising a polishing pad can improve the particle level in the polishing pad life early stage.