| 摘要 |
Flat-surfaced workpieces such as semiconductor wafers are held in flat-surfaced abrading contact with the abrasive surface of a flexible raised-island disk that is attached to a flat-surfaced rotating platen. There are recessed areas between the abrasive-coated raised islands where light can transmitted through the transparent backings. Platens are constructed with open passageways that extend radially from the outer periphery of the platen to the area that is under the abraded wafer. Stationary light sources are directed radially to the platen edge where they enter the open passageways to impinge on mirrors that direct the light to contact the surface of the wafer. The light beams reflected from the wafer surface are directed with mirrors back to a stationary light-receiver positioned at the outer periphery of the platen. The light-receiver device allows abraded condition of the flat surface of the wafer to be monitored during the abrasive lapping or polishing procedure. |
