초록 ▼

A chemical mechanical polishing apparatus includes a platen to support a polishing pad, and a polishing head to hold a substrate against the polishing pad during processing. The substrate includes a thin film structure disposed on a wafer. A first optical system includes a first light source to gene

A chemical mechanical polishing apparatus includes a platen to support a polishing pad, and a polishing head to hold a substrate against the polishing pad during processing. The substrate includes a thin film structure disposed on a wafer. A first optical system includes a first light source to generate a first light beam which impinges on a surface of the substrate, and a first sensor to measure light reflected from the surface of the substrate to generate a measured first interference signal. A second optical system includes a second light source to generate a second light beam which impinges on a surface of the substrate and a second sensor to measure light reflected from the surface of the substrate to generate a measured second interference signal. The second light beam has a wavelength different from the first light beam.

대표청구항 ▼

[ What is claimed is:] [1.]1. An apparatus for use in chemical mechanical polishing a substrate having a first surface and a second surface underlying the first surface, comprising:a first optical system including a first light source to generate a first light beam to impinge on the substrate, the f

[ What is claimed is:] [1.]1. An apparatus for use in chemical mechanical polishing a substrate having a first surface and a second surface underlying the first surface, comprising:a first optical system including a first light source to generate a first light beam to impinge on the substrate, the first light beam having a first effective wavelength, and a first sensor to measure light from the first light beam that is reflected from the first and second surfaces to generate a first interference signal;a second optical system including a second light source to generate a second light beam that impinges the substrate, the second light beam having a second effective wavelength which differs from the first effective wavelength, and a second sensor to measure light from the second light beam that is reflected from the first and second surfaces to generate a second interference signal; anda processor configured to determine a thickness from the first and second interference signals.