A grindstone corresponding to a rotatable grindstone or a stationary grindstone can be incorporated in a grinding device and is used for grinding raw materials. The grindstone includes a main body part and an outer circumferential ring part that can be detached from each other. The main body part has a coarse grinding part in which coarse grinding grooves corresponding to first coarse grinding grooves and second coarse grinding grooves for initially grinding the raw materials are formed. The outer circumferential ring part has a fine grinding part corresponding to a wall part in which fine grinding grooves for further grinding the raw materials ground by the coarse grinding part are formed. When the main body part and the outer circumferential ring part are assembled, the fine grinding part corresponding to the wall part is located at an outer circumference of the coarse grinding part.

A method of detecting a polishing endpoint includes storing a plurality of library spectra, measuring a sequence of spectra from the substrate in-situ during polishing, and for each measured spectrum of the sequence of spectra, finding a best matching library spectrum from the plurality of library spectra to generate a sequence of best matching library spectra. Each library spectrum has a stored associated value representing a degree of progress through a polishing process, and the stored associated value for the best matching library spectrum is determined for each best matching library spectrum to generate a sequence of values representing a progression of polishing of the substrate. The sequence of values is compared to a target value, and a polishing endpoint is triggered when the sequence of values reaches the target value.

Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting a reference spectrum. The reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectrum is empirically selected for particular spectrum-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectrum-based endpoint logic. The method includes obtaining a current spectrum. The current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved. The determining is based on the reference and current spectra.

Methods and apparatus for spectrum-based endpointing. An endpointing method includes selecting a reference spectrum. The reference spectrum is a spectrum of white light reflected from a film of interest on a first substrate and has a thickness greater than a target thickness. The reference spectrum is empirically selected for particular spectrum-based endpoint determination logic so that the target thickness is achieved when endpoint is called by applying the particular spectrum-based endpoint logic. The method includes obtaining a current spectrum. The current spectrum is a spectrum of white light reflected from a film of interest on a second substrate when the film of interest is being subjected to a polishing step and has a current thickness that is greater than the target thickness. The method includes determining, for the second substrate, when an endpoint of the polishing step has been achieved. The determining is based on the reference and current spectra.

A polishing tool includes a polishing surface having a spherical zone shape and having a plurality of non-contact portions provided from an inner edge to an outer edge of the polishing surface so as not to contact with a workpiece. The plurality of non-contact portions is a plurality of grooves whose widths in a circumferential direction increase from the inner edge toward the outer edge. A polishing method using the polishing tool includes: rotating the polishing tool about the central axis of rotation; and simultaneously with rotating the polishing tool, swinging relatively at least one of the workpiece and the polishing tool with a predetermined swing width, around a position where a line passing through a center of the workpiece and intersecting with the central axis of rotation passes through a center in a width direction of a spherical zone of the polishing surface, thereby polishing the workpiece.

The disclosed technology includes a cutting tool comprising segments arranged around a periphery of a cutting tool. Each segment, of the plurality of segments comprising a first portion comprising a first material having a first hardness, a second portion comprising a second material having a second hardness, the second hardness being less than the first hardness, and a transition region. The transition region can include at least part of the first material and at least part of the second material. The transition region can have an overall third hardness that is less than the first hardness and greater than the second hardness. A first segment and a second segment of the plurality of segments can be attached to the periphery of the cutting tool such that at least the first portion of the first segment is aligned in a cutting direction with the second portion of the second segment.

The disclosed technology includes a cutting tool comprising segments arranged around a periphery of a cutting tool. Each segment, of the plurality of segments comprising a first portion comprising a first material having a first hardness, a second portion comprising a second material having a second hardness, the second hardness being less than the first hardness, and a transition region. The transition region can include at least part of the first material and at least part of the second material. The transition region can have an overall third hardness that is less than the first hardness and greater than the second hardness. A first segment and a second segment of the plurality of segments can be attached to the periphery of the cutting tool such that at least the first portion of the first segment is aligned in a cutting direction with the second portion of the second segment.

A method of grinding a wafer includes positioning a wafer beneath a grinding wheel and aligning the wafer and the grinding wheel. The method further includes contacting a grinding surface of an outer base of the grinding wheel with the wafer while rotating at least one of the wafer and the grinding wheel, contacting a grinding surface of an inner frame of the grinding wheel with the wafer while rotating at least one of the wafer and the grinding wheel, without changing the alignment between the wafer and the grinding wheel, and tilting one of the wafer and the grinding wheel relative to the other during at least one of the first and the second contacting steps. The method also includes removing the wafer from the position beneath the grinding wheel.

A method of grinding a wafer includes positioning a wafer beneath a grinding wheel and aligning the wafer and the grinding wheel. The method further includes contacting a grinding surface of an outer base of the grinding wheel with the wafer while rotating at least one of the wafer and the grinding wheel, contacting a grinding surface of an inner frame of the grinding wheel with the wafer while rotating at least one of the wafer and the grinding wheel, without changing the alignment between the wafer and the grinding wheel, and tilting one of the wafer and the grinding wheel relative to the other during at least one of the first and the second contacting steps. The method also includes removing the wafer from the position beneath the grinding wheel.

A grinding wheel includes a disc-like member and a grinding stone layer disposed on an outer peripheral surface of the disc-like member. A grinding surface of the grinding stone layer includes a cylinder grinding surface, end grinding surfaces, and corner grinding surfaces. The grinding stone layer includes a cylindrical-portion grinding stone layer including a part of the corner grinding surfaces and the cylinder grinding surface, and end grinding stone layers including the remaining part of the respective corner grinding surfaces and the respective end grinding surfaces and having a property different from a property of the cylindrical-portion grinding stone layer. Joint surfaces are each formed by joining a boundary surface of the cylindrical-portion grinding stone layer and a boundary surface of the end grinding stone layer such that the boundary surfaces have a preset inclination to an axis of rotation.