Patent ID: 7204934

Claim:
A method for processing recess etch operations in substrates, comprising: a) forming a hard mask over the substrate; b) etching a trench in the substrate using the hard mask; c) forming a dielectric layer over the hard mask and in the trench, the electric layer configured to line the trench; d) applying a conductive material over the dielectric layer such that a blanket of the conductive material lies over the hard mask and fills the trench; e1) planarization etching the conductive material to substantially planarize the conductive material; e2) utilizing interferometric endpoint detection to identify an endpoint of the planarization etching, the endpoint of the planarization etching occurring so as to leave a portion of the conductive material over the dielectric layer that overlies the hard mask; e3) stopping the planarization etching upon identification of the endpoint of the planarization etching; and f) recess etching the conductive material so as to remove the conductive material over the dielectric layer that overlies the hard mask and removes at least part of the conductive material from within the trench, wherein the recess etching is performed using a different chemistry than that used to perform the planarization etching.