INDUCTIVE MONITORING OF CONDUCTIVE TRENCH DEPTH

摘要

In fabrication of an integrated circuit having a layer with a plurality of conductive interconnects, a layer of a substrate is polished to provide the layer of the integrated circuit. The layer of the substrate includes conductive lines to provide the conductive interconnects. The layer of the substrate includes a closed conductive loop formed of a conductive material in a trench. A depth of the conductive material in the trench is monitored using an inductive monitoring system and a signal is generated. Monitoring includes generating a magnetic field that intermittently passes through the closed conductive loop. A sequence of values over time is extracted from the signal, the sequence of values representing the depth of the conductive material over time.

主权项

1. A method of chemical mechanical polishing a substrate, comprising:
in fabrication of an integrated circuit having a layer with a plurality of conductive interconnects, polishing a layer of a substrate to provide the layer of the integrated circuit, wherein the layer of the substrate includes conductive lines to provide the conductive interconnects, and wherein the layer of the substrate includes a closed conductive loop formed of a conductive material in a trench; monitoring a depth of the conductive material in the trench using an inductive monitoring system and generating a signal, wherein monitoring includes generating a magnetic field that intermittently passes through the closed conductive loop; and extracting from the signal a sequence of values over time, the sequence of values representing the depth of the conductive material over time; and at least one of
detecting a polishing endpoint by determining from the sequence of values that a depth of the conductive material has reached a target depth, oradjusting at least one pressure applied by a carrier head to the substrate during polishing of the layer based on the sequence of values such that different zones on the substrate have closer to the same endpoint time than without such an adjustment.