Method and apparatus for controlling flatness of polished semiconductor wafers

摘要

Apparatus (10; 104) for determining the flatness of a generally circular polishing pad (12) through direct measurement of the pad (12) for use in maintaining the flatness of the pad (12) and the flatness of surfaces of articles polished on the polishing pad (12) of a polisher (16). The apparatus (10; 104) includes a measuring device (26), a frame (24) mounting the measuring device (26) being capable of measuring a distance between an upper surface (27) of the polishing pad (12) and a reference plane (P1) at plural locations along the polishing pad (12). The apparatus (10; 104) further includes a controller (102) for controlling the measuring device (26). The controller (102) is configured to indicate whether the flatness of the pad (12) falls outside a predetermined specification.