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US 7,008,295 B2Granted
Substrate monitoring during chemical mechanical polishing
AssigneeApplied Materials, Inc.
InventorsAndreas Norbert Wiswesser, Manoocher Birang, Boguslaw A. Swedek
Life of this patent
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Abstract
Methods and apparatus for monitoring a substrate surface during chemical mechanical polishing are disclosed.
Claims53
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- and
- monitoring light from the surface of the substrate with a detector having a plurality of detector elements including a first detector element and a second detector element;
- wherein monitoring includes selectively using data from the first detector element collected in a first portion of the polishing step and disregarding data from the second detector element collected during the first portion of the polishing step so as to improve a signal to noise ratio of data from the detector.
1 more element
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- and
- selectively monitoring light from the surface of the substrate with a detector having a plurality of detector elements;
- wherein selectively monitoring light comprises simultaneously detecting light reflected from a plurality of regions on the surface of the substrate, and monitoring a plurality of intensity signals corresponding to the intensity of light reflected from the plurality of regions on the substrate surface.
1 more element
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- and
- selectively monitoring light from the surface of the substrate with a detector having a plurality of detector elements;
- wherein selectively monitoring light from the surface of the substrate comprises measuring a reflectance signal from each of the plurality of detector elements.
1 more element
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- and
- selectively monitoring light from the surface of the substrate with a detector having a plurality of detector elements;
- wherein selectively monitoring light from the surface of the substrate comprises measuring an interference signal from each of the plurality of detector elements.
1 more element
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- and
- monitoring light from the surface of the substrate with a detector having a plurality of detector elements including a first detector element and a second detector element, wherein the detector moves relative to the substrate to provide a plurality of scans of the substrate,
- wherein, monitoring includes selectively using data from the first detector element collected during a first portion of the polishing step and disregarding data from the second detector element collected during the first portion of the polishing state so as to monitor substantially the same portion of the substrate surface during two or more scans from the plurality of scans.
1 more element
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- and
- monitoring light from the surface of the substrate with a detector having a plurality of detector elements;
- wherein, during at least a first portion of the polishing step, light from the substrate surface is monitored with a first deflector element and light is not monitored with a second detector element;
- and
- wherein monitoring light comprises simultaneously detecting light reflected from a plurality of regions on the surface of the substrate, and monitoring a plurality of intensity signals corresponding to the intensity of light reflected from the plurality of regions on the substrate surface.
3 more elements
A method for measuring a characteristic of a layer on a substrate during chemical-mechanical polishing, the method comprising:
- bringing a surface of the substrate into contact with a polishing pad that has a window;
- causing relative motion between the substrate and the polishing pad;
- directing a light beam through the window, the motion of the polishing pad relative to the substrate causing the light beam to move in a path across the substrate surface;
- simultaneously detecting light reflected from a plurality of regions in the path on the on the substrate surface;
- monitoring a plurality of intensity signals corresponding to the intensity of light reflected from the plurality of regions in the path on the substrate surface;
- extracting a plurality of intensity measurements from each of the intensity signals, each intensity measurement corresponding to a sampling zone in one of the regions in the path across the substrate surface;
- determining a distance between each of the sampling zones and a reference location on the substrate surface;
- selecting intensity measurements based on the distance between the sampling zones and the reference location;
- and
- computing the characteristic of the layer on the substrate from the selected intensities.
7 more elements
A substrate polishing system, comprising:
- a polishing pad having an opening;
- a polishing head configured to hold a substrate adjacent the polishing pad during use of the system;
- a light source configured so that, when the substrate is adjacent the polishing pad, the light source is capable of directing a light beam to an area of a surface of the substrate through the opening in the polishing pad;
- an array of light detectors configured to detect light from the area of the surface, the light detectors each being configured to be capable of detecting light from a respective region of the area of the surface of the substrate;
- and
- a controller for selectively monitoring the light detected by the array of light detectors.
3 more elements
A substrate polishing system, comprising:
- a polishing pad having an opening;
- a polishing head configured to hold a substrate adjacent the polishing pad during use of the system;
- a light source configured so that, when the substrate is adjacent the polishing pad, the light source is capable of directing a light beam to an area of a surface of the substrate through the opening in the polishing pad;
- an array of light detectors configured to detect light from the area of the surface, the light detectors each being configured to be capable of detecting light from a respective region of the area of the surface of the substrate;
- and
- a means for selectively monitoring the light detected by the array of light detectors.
3 more elements
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- during polishing illuminating an area of the surface of the substrate with light from a light source;
- and
- monitoring light from the light source after the light interacts with the area of the surface of the substrate with a detector having a plurality of detector elements, each of the plurality of detector elements receiving light from a different portion of the area of the surface of the substrate illuminated by the same light source.
1 more element
A substrate polishing system, comprising:
- a movable platen;
- a polishing head configured to hold a substrate adjacent to a polishing pad during use of the system;
- and
- at least one optical monitoring system including a light source connected to the movable plater, wherein the a light source is configured so that, when the substrate is adjacent the polishing pad, the light source is configured to direct a light beam to an area of a surface of the substrate through the opening in the polishing pad during polishing and the optical monitoring system further including a detector having a plurality of light detector elements configured to detect light from different portions of the area illuminated by the same light source after the light interacts with the area of the surface of the substrate.
1 more element
A method for polishing a surface of a substrate, comprising:
- chemical-mechanical polishing the surface of the substrate;
- monitoring light from the surface of the substrate with a detector having a plurality of detector elements;
- detecting a polishing endpoint, the detecting including (i) selecting a first measurement corresponding to light detected by a first detector element at a particular time, and (ii) excluding a second measurement corresponding to light detected by a different detector element at that particular time.
A substrate monitoring system, comprising:
- a light source to illuminate a substrate during polishing;
- a detector to detect light from the substrate, the detector including a plurality of detector elements including a first detector element and a second detector element;
- and
- a controller to receive data from the detector and configured to selectively use data from the first detector element collected in a first portion of the polishing step and disregard data from the second detector element collected during the first portion of the polishing step so as to improve a signal to noise ratio of data from the detector.
1 more element
A substrate monitoring system, comprising:
- a light source to illuminate a substrate during polishing;
- a detector to detect light from the substrate, the detector including a plurality of detector elements including a first detector element and a second detector element;
- and
- a controller to receive data from the detector and configured to selectively use data from the first detector element collected in a first portion of the polishing step and disregard data from the second detector element collected during the first portion of the polishing step so as to improve a signal to noise ratio of data from the detector.
1 more element
Dependencies are inferred from the claim text.