Patent ID: 7101252
Filing Date: 2006-09-05
Classification: B24B,H01L

Abstract:
1. A polishing method for chemical mechanical polishing of an oxide film adjacent to a protective film formed proximate to a substrate having recesses, the method comprising: a first step of planarizing the oxide film by bringing the oxide film into contact with a polishing pad, supplying a polishing agent containing cerium oxide particles between the oxide film and the polishing pad, and causing relative rotational motion between the substrate and the polishing pad; a second step of continuing to polish the oxide film once the oxide film has been planarized, thereby maintaining the planarized property of the oxide film; a third step of continuing to polish the oxide film until at least a portion of the protective film becomes exposed; a fourth step of continuing to polish the oxide film until the oxide film is substantially removed and the protective film is substantially exposed; measuring torque on the substrate or on the polishing pad either continuously or at intervals during the first through fourth steps; and determining changes in torque with time to determine the status of each of the first through fourth steps concurrently with the polishing method; wherein one or more transition points between at least two adjacent steps of the first through steps are detected based at least in part on the determined changes in torque with time; and wherein a transition point is detected between the first and second steps by determining a time point at which the determined change in torque with time goes from a positive value to a value of approximately zero.