Apparatus for in-situ optical endpointing on web-format planarizing machines in mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies and methods for making and using same

A polishing pad for chemical-mechanical planarization of microelectronic-device substrate assemblies, comprising:

• an optically transmissive backing sheet having a top surface and an under surface;
• a backing pad attached to the under surface of the backing sheet, the backing pad having at least one viewing port;
• and
• a planarizing medium disposed on the top surface of the backing sheet, the planarizing medium having at least one viewing port at least partially aligned with the viewing port in the backing pad.

A planarizing machine for mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies, comprising:

• a table including a support surface having a first dimension extending along a pad travel path, a second dimension transverse to the first dimension and a planarizing at zone at least within the first and second dimensions;
• a light source under to the table at an illumination site from which a light beam can emanate from the support surface of the table;
• a polishing pad moveably coupled to the support surface of the table, the pad including a planarizing medium and an optical pass-through system, wherein the planarizing medium includes a planarizing surface configured to engage a substrate assembly and a backside to face towards the table, and wherein the optical pass-through system includes a plurality of view sites along a length of the pad in a direction generally parallel to the pad travel path, each view site providing an optically transmissive path through the pad;
• a pad advancing mechanism engaged with the pad, the advancing mechanism being configured to move the pad over the table along the pad travel path to place a fresh portion of the planarizing, surface at one side of a planarizing zone on the table and to remove a worn portion of the planalizing surface from an opposite side of the planarizing zone;
• and
• a carrier assembly having a head for holding a substrate assembly and a drive assembly connected to the head to move the substrate assembly with respect to the polishing pad.

A planarizing machine for mechanical or chemical-mechanical planarization of microelectronic-device substrate assemblies, comprising:

• a table including a support surface having a first dimension extending along a pad travel path, a second dimension transverse to the first dimension and a planarizing at zone at least within the first and second dimensions;
• a light source attached to the table at an illumination site from which a light beam can emanate from the support surface of the table;
• a polishing pad moveably coupled to the support surface of the table, the pad including an optically transmissive backing sheet having an under surface facing the table and a top surface, the pad also including a planarizing medium disposed on the top surface of the backing sheet, and the planarizing medium having at least one opening configured to be aligned with the illumination site in the table;
• a pad advancing mechanism engaged with the pad, the advancing mechanism configured to move the pad over the table along the pad travel path to place a fresh portion of the planarizing surface at one end of a planarizing zone on the table and to remove a worn portion of the planarizing surface from an opposite end of the planarizing zone;
• and
• a carrier assembly having a head for holding a substrate assembly and a drive assembly connected to the head to move the substrate assembly with respect to the polishing pad.

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 in a 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.

A method for planarizing microelectronic-device substrate assemblies, comprising:

• removing material from a first substrate assembly by pressing the first substrate assembly against a planarizing surface of a polishing pad and moving the first substrate assembly with respect to the polishing pad;
• initially passing a light beam from an illumination site in the table through an optically transmissive view site in the polishing pad to at least periodically impinge the first substrate assembly with the light beam and optically sense a surface condition of the first substrate assembly until the sensed surface condition indicates that the first substrate assembly has reached a desired endpoint;
• advancing the polishing pad relative to the table and the illumination site after planarizing the first substrate assembly;
• removing material from a second substrate assembly by pressing the second substrate assembly against the planarizing surface of the polishing pad and moving the second substrate assembly with respect to the polishing pad;
• and
• subsequently passing a light beam from the illumination site in the table through another optically transmissive view site in the polishing pad to at least periodically impinge the second substrate assembly with the light beam and optically sense a surface condition of the second substrate assembly until the sensed surface condition indicates that the second substrate assembly has reached a desired endpoint.