A polishing apparatus has a polishing pad, a top ring for holding a semiconductor wafer, and a vertical movement mechanism operable to move the top ring in a vertical direction. The polishing apparatus also has a distance measuring sensor operable to detect a position of the top ring when a lower surface of the top ring is brought into contact with the polishing pad, and a controller operable to calculate an optimal position of the top ring to polish the semiconductor wafer based on the position detected by the distance measuring sensor. The vertical movement mechanism includes a ball screw mechanism operable to move the top ring to the optimal position.

The present disclosure describes a method and apparatus to remove consumable (e.g., sacrificial) polishing pad layers from a multilayer polishing pad. For example, the method includes measuring a thickness profile of a top polishing pad layer of a multilayer polishing pad and comparing the thickness profile to a threshold. The method, in response to the thickness profile being above the threshold, rinses the top polishing pad layer of the multilayer polishing pad and removes, after the top polishing pad layer has been rinsed, the top polishing pad layer to expose an underlying polishing pad layer of the multilayer polishing pad.

A grinding robot for grinding an electrically conducting workpiece. The grinding robot includes a grinding wheel, an actuation device for actuating grinding wheel, and a control system. The grinding wheel including an undulated tool receptacle which defines an axis of rotation about which the grinding wheel can rotate during grinding, and a head which is rotationally symmetrical with respect to the axis of rotation, and which contains abrasive material and has a grinding surface which is in contact with workpiece during grinding. The grinding wheel also includes a measuring and transmission unit and at least one conductor strand pair with two conductor strands which are electrically insulated from one another. The conductor strands are embedded in the rotationally symmetrical head and extend from the grinding surface of the head into the interior of the head and are electrically connected with measuring and transmission unit.

A method which is executed in a grinding machine comprising a) rotationally driving a cup grinding wheel around an axis of rotation of a tool spindle at a first speed, b) rotationally driving a dressing tool around an axis of rotation of a dressing spindle at a second speed, c) carrying out a dressing method using the dressing tool, wherein a predetermined, fixed speed ratio is specified between the first speed and the second speed, and after steps (a), (b), and (c): i. eccentrically rotationally driving the cup grinding wheel around the axis of rotation of the tool spindle at a first machining speed using the eccentric drive, ii. carrying out a grinding method, wherein the bevel gear workpiece is machined by grinding using the cup grinding wheel.

A method which is executed in a grinding machine comprising a) rotationally driving a cup grinding wheel around an axis of rotation of a tool spindle at a first speed, b) rotationally driving a dressing tool around an axis of rotation of a dressing spindle at a second speed, c) carrying out a dressing method using the dressing tool, wherein a predetermined, fixed speed ratio is specified between the first speed and the second speed, and after steps (a), (b), and (c): i. eccentrically rotationally driving the cup grinding wheel around the axis of rotation of the tool spindle at a first machining speed using the eccentric drive, ii. carrying out a grinding method, wherein the bevel gear workpiece is machined by grinding using the cup grinding wheel.

The various described embodiments provide a CMP system and a method of using the same. The CMP system includes an imaging device, such as a laser scanner, that obtains an image of a dresser of the CMP system in real time or in-situ with a CMP process. A processing device of the CMP system compares the obtained image with one or more of reference images to determine whether or not the dresser has a defect. The processing device then adjusts the CMP process based on whether or not the dresser includes a defect.

The various described embodiments provide a CMP system and a method of using the same. The CMP system includes an imaging device, such as a laser scanner, that obtains an image of a dresser of the CMP system in real time or in-situ with a CMP process. A processing device of the CMP system compares the obtained image with one or more of reference images to determine whether or not the dresser has a defect. The processing device then adjusts the CMP process based on whether or not the dresser includes a defect.

The present invention relates to a technique of determining a time to replace a polishing pad used in a polishing apparatus for polishing a workpiece, such as wafer, substrate, or panel. A polishing apparatus (1) includes: a polishing table (5) configured to support a polishing pad (2); a polishing head (7) configured to press a workpiece (W) against a polishing surface (2a) of the polishing pad (2); a dresser (40) configured to dress the polishing surface (2a) of the polishing pad (2); a detection sensor (60) configured to detect friction between the dresser (40) and the polishing pad (2), the detection sensor (60) being fixed to the dresser (40); and a wear monitoring device (63) configured to determine a wear index value from a plurality of output values of the detection sensor (60) and generate an alarm signal when the wear index value is smaller than a predetermined lower limit.

A grinding apparatus includes a chuck, a housing, a tool driving unit, a nozzle, a sensor and a sensor cover. The chuck is configured to hold a substrate. The housing accommodates the chuck therein. The tool driving unit is configured to drive a grinding tool pressed against the substrate within the housing. The nozzle is configured to supply a grinding liquid to the substrate within the housing. The sensor is disposed at an inside of the housing and is configured to detect a liquid level of a liquid collected within the housing. The sensor cover is located between the chuck and the sensor.

A grinding apparatus includes a chuck, a housing, a tool driving unit, a nozzle, a sensor and a sensor cover. The chuck is configured to hold a substrate. The housing accommodates the chuck therein. The tool driving unit is configured to drive a grinding tool pressed against the substrate within the housing. The nozzle is configured to supply a grinding liquid to the substrate within the housing. The sensor is disposed at an inside of the housing and is configured to detect a liquid level of a liquid collected within the housing. The sensor cover is located between the chuck and the sensor.