Patent ID: 6702647
Filing Date: 2004-03-09
Classification: B24B,H01L

Abstract:
An apparatus for detecting removal of material from a substrate, the substrate having a first surface and a second surface opposite the first surface, the substrate being light transmissive from the first surface to a point proximate the second surface, the second surface having a reflective layer attached thereto, the device comprising:a platen having a planarizing surface; a carrier having a first surface and a second surface opposite the first surface, the second surface of the carrier being configured to receive the substrate and engage the substrate with the planarizing surface of the platen, the carrier and substrate being movable relative to the platen when the substrate is engaged with the planarizing surface to remove the reflective layer from the substrate; a light source positioned proximate to the first surface of the substrate to irradiate the first surface, the light source being fixed relative to the carrier and moving with the carrier; and a light sensor positioned proximate to the first surface of the substrate to detect light reflected from the reflective layer of the substrate through the first surface of the substrates the light sensor being fixed relative to the carrier and moving with the carrier.