Polishing method and apparatus
First Claim
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.
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Accused Products
Abstract
A chemical mechanical polishing method for polishing an oxide film and a protective film formed on a substrate having recesses comprises four steps. The first step planarizes the oxide film using a polishing pad and a polishing agent containing cerium oxide particles by causing relative rotational motion between the substrate and the polishing pad. The second step continues polishing the oxide film to maintain the planarized property of the oxide film. The third step polishes the oxide film until at least a portion of the protective film becomes exposed. The fourth step polishes the oxide film until the oxide film is substantially removed and the protective film is substantially exposed. During the four steps, torque values are measured on the substrate or the polishing pad, and changes in torque with time are calculated. This information is used to determine the status of each of the steps during the polishing run.
57 Citations
17 Claims
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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:
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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. - View Dependent Claims (2, 4, 10, 11, 12, 13, 14, 15, 16, 17)
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3. A polishing method for chemical mechanical polishing of an oxide film adjacent to protective film formed proximate to a substrate having recesses, the method comprising:
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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 fourth 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 second and third steps by determining a time point at which the determined change in torque with time goes from a value of approximately zero to a negative value.
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5. 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:
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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 anomaly in a least one of the first through fourth steps is detected by comparing the determined changes in torque with time to a reference pattern that is predetermined based on one or more of the oxide film, the protective film, and the polishing agent. - View Dependent Claims (6, 7, 8, 9)
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Specification