Endpoint detector for a chemical mechanical polishing system
AssigneeApplied Materials, Inc.
InventorManoocher Birang
Life of this patent
Estimating the term…
Abstract
An endpoint detector for a substrate polishing apparatus integrates a signal indicative of the instantaneous material removal rate from the substrate. The signal is generated by a monitor which measures a motor parameter such as torque or current draw. The resulting sum is compared to a baseline sum known to yield the desired polishing to predict the polishing endpoint.
Claims15
An endpoint detector for a chemical mechanical polishing apparatus having a polishing surface, a positioning member for positioning a substrate in contact with the polishing surface, and a motor for creating relative movement between the polishing surface and the substrate, comprising:
- a monitor to measure the power input to the motor and generate an output signal representing the power input;
- an accumulator to sum the output signal over time;
- and
- a comparator to compare the sum to a reference value to indicate when an endpoint condition has been reached.
A method of determining the polishing endpoint of a substrate polished on a polishing surface, wherein the polishing surface and substrate are moved with respect to one another by a motor, comprising the steps of:
- summing a condition of the motor which is indicative of the frictional load on the motor;
- and
- comparing that sum to a reference value to detect a polishing endpoint.
An endpoint detector for a chemical mechanical polishing apparatus having a polishing surface, a positioning member for positioning the substrate in contact with the polishing surface, and a plurality of motors for creating relative movement between the polishing surface and the substrate, comprising:
- a plurality of monitors for measuring a power input to each motor and generating a plurality of output signals representing the power input to each motor;
- an accumulator to receive the output signals and sum the output signals over time;
- and
- a comparator to compare the sum to a reference value and indicate an endpoint condition when the reference value has been reached.
An endpoint detector for a chemical mechanical polishing apparatus having a polishing surface, a positioning member for positioning the substrate in contact with the polishing surface, and a motor for creating relative movement between the polishing surface and the substrate, comprising:
- a monitor for measuring a power input to the motor and generating an output signal representing the power input;
- and
- a processor to receive the output signal and sum it over time and to compare the sum to a reference value to indicate when an endpoint condition has been reached.
Dependencies are inferred from the claim text.