Methods for polishing semiconductor substrates that involve adjusting the finish polishing sequence based on the pad-to-pad variance of the polishing pad are disclosed.

A method includes: polishing a semiconductor wafer by a polishing device; measuring a form of the semiconductor wafer by a measuring device before a polished surface of the semiconductor wafer becomes hydrophilic; and setting polishing conditions for the polishing based on a measurement result of the form of the semiconductor wafer by a polishing condition setting unit.

Disclosed is a method for determining location of a lens machining tool (24) having an offset location according to a first direction (Y) smaller than a first predetermined threshold, including the steps of manufacturing a calibration piece (10) according to a predetermined theoretical geometry by using the lens machining tool for providing a at least partially annular groove in a main surface of the calibration piece, the at least partially annular groove being configured to form at least one sharp edge defining a slope discontinuity on the main surface; measuring a distance between the at least one sharp edge and a turning center of the calibration piece for providing data of geometrical characteristics of the calibration piece; and deducing from the measured data a location of the lens machining tool according to a second direction (X) distinct from the first direction.

Disclosed is a method for determining location of a lens machining tool (24) having an offset location according to a first direction (Y) smaller than a first predetermined threshold, including the steps of manufacturing a calibration piece (10) according to a predetermined theoretical geometry by using the lens machining tool for providing a at least partially annular groove in a main surface of the calibration piece, the at least partially annular groove being configured to form at least one sharp edge defining a slope discontinuity on the main surface; measuring a distance between the at least one sharp edge and a turning center of the calibration piece for providing data of geometrical characteristics of the calibration piece; and deducing from the measured data a location of the lens machining tool according to a second direction (X) distinct from the first direction.

A grinding stroke control device for a valve stem grinding apparatus is fixed to a processing machine and provided for gripping a valve stem or a test bar. Using the hand wheel, the dial gauge and the positioning seat can obtain an initial position, then moving the measuring meter of the positioning mechanism along the transverse direction to make sure the valve stem has the right length with a standard valve clearance. By such arrangements, the grinding stroke control device for a stem valve grinding apparatus of the invention can have a less complicated structure and therefore is more convenient to operate.

A grinding stroke control device for a valve stem grinding apparatus is fixed to a processing machine and provided for gripping a valve stem or a test bar. Using the hand wheel, the dial gauge and the positioning seat can obtain an initial position, then moving the measuring meter of the positioning mechanism along the transverse direction to make sure the valve stem has the right length with a standard valve clearance. By such arrangements, the grinding stroke control device for a stem valve grinding apparatus of the invention can have a less complicated structure and therefore is more convenient to operate.

A grinding device is operated by grinding of a surface of the workpiece with at least one grinding medium while recording actual data of the surface after grinding with at least one data collection device. Actual data recorded during grinding is then compared with target data stored in an electronic memory in an electronic data processing device. Based on the comparison, adjustments are made to at least one grinding parameter if a deviation of the actual data from the target data exceeds a predetermined limit.

A grinding device is operated by grinding of a surface of the workpiece with at least one grinding medium while recording actual data of the surface after grinding with at least one data collection device. Actual data recorded during grinding is then compared with target data stored in an electronic memory in an electronic data processing device. Based on the comparison, adjustments are made to at least one grinding parameter if a deviation of the actual data from the target data exceeds a predetermined limit.

The present invention relates to a polishing method and a polishing apparatus for polishing a substrate such as a wafer while measuring a film thickness based on optical information included in reflected light from the substrate. The polishing method includes preparing a plurality of spectrum groups each containing a plurality of reference spectra corresponding to different film thicknesses; directing light to a substrate and receiving reflected light from the substrate; producing, from the reflected light, a sampling spectrum for selecting a spectrum group; selecting a spectrum group containing a reference spectrum which is closest in shape to the sampling spectrum; producing a measurement spectrum for obtaining a film thickness while polishing the substrate; selecting, from the selected spectrum group, a reference spectrum which is closest in shape to the measurement spectrum that has been produced when the substrate is being polished; and obtaining a film thickness corresponding to the selected reference spectrum.

The present invention relates to a polishing method and a polishing apparatus for polishing a substrate such as a wafer while measuring a film thickness based on optical information included in reflected light from the substrate. The polishing method includes preparing a plurality of spectrum groups each containing a plurality of reference spectra corresponding to different film thicknesses; directing light to a substrate and receiving reflected light from the substrate; producing, from the reflected light, a sampling spectrum for selecting a spectrum group; selecting a spectrum group containing a reference spectrum which is closest in shape to the sampling spectrum; producing a measurement spectrum for obtaining a film thickness while polishing the substrate; selecting, from the selected spectrum group, a reference spectrum which is closest in shape to the measurement spectrum that has been produced when the substrate is being polished; and obtaining a film thickness corresponding to the selected reference spectrum.