Patent ID: 6191037
Filing Date: 2001-02-20
Classification: B24B,H01L

Abstract:
A method for planarization of a microelectronic-device substrate assembly carried by a substrate holder and having a polishing pad attached to a table, comprising,fabricating an endpoint indicator having a first coefficient of friction at an endpoint elevation wherein the fabricating comprises treating a surface of the endpoint indicator to impart a different coefficient of friction to the endpoint indicator that the first coefficient of friction;forming a non-planar cover layer having a second coefficient of friction over the endpoint indicator wherein forming the cover layer comprises depositing a dielectric layer over the treated surface of the endpoint indicator;removing material from the cover layer by pressing the cover layer against a polishing pad and imparting relative motion between the substrate assembly and the polishing pad, wherein imparting relative motion between the substrate surface and the polishing pad comprises moving at least one of the substrate holder and the table in a plane;detecting a first change in drag force between the substrate assembly and the polishing pad indicating planarity of the substrate assembly in the cover layer, wherein detecting the first change in drag force comprises measuring an increase in current through a drive motor driving at least one of the substrate holder and the table from a start current to a planarity current indicating a planar substrate surface in the dielectric layer; andidentifying a second change in drag force between the substrate assembly and the polishing pad upon exposure of the endpoint indicator at the endpoint elevation for the planarizing process, wherein identifying the second change in drag force comprises measuring a decrease in current through the drive motor from the planarity current to an endpoint current at the treated surface of the endpoint indicator andstopping removal of material from the substrate surface upon identifying the second change in drag force between the substrate assembly and the polishing pad.