Patent ID: 6929530
Filing Date: 2005-08-16
Classification: B24B

Abstract:
1. A method of endpointing mechanical or chemical-mechanical planarization processing of microelectronic-device substrate assemblies, comprising: initially passing a light beam from an illumination site in a table through a first optically transmissive view site located at a first area within a first elongated slot in a planarizing medium disposed on the polishing pad to at least periodically impinge a first substrate assembly with the light beam and optically sense a surface condition of the first substrate assembly; advancing the polishing pad relative to the table and the illumination site after planarizing the first substrate assembly; and subsequently passing a light beam from the illumination site in the table through a second optically transmissive view site in the polishing pad to at least periodically impinge a second substrate assembly with the light beam and optically sense a surface condition of the second substrate assembly the second view site being located a second area of the elongated slot spaced apart from the first area; wherein the polishing pad comprises: an optically transmissive backing sheet having a top surface and an under surface with the planarizing medium being disposed on the top surface; a backing pad attached to the under surface of the backing sheet; and the first elongated slot in the polishing pad is alignable with the illumination site in the table and at least one orifice in the backing pad is at least partially aligned with the first elongated slot, thereby forming an optical pass through system in the polishing pad.