Methods and apparatus for polishing control
AssigneeApplied Materials, Inc.
InventorsManoocher Birang, Konstantin Y. Smekalin, David A. Chan
Life of this patent
Estimating the term…
Abstract
A CMP station can be closed loop controlled by using data obtained by an inline metrology station from a first polished wafer to affect the processing of subsequent polished wafers. The first wafer is polished and measured by the inline metrology station. The metrology station measures at various points the array dielectric thickness, field dielectric thickness, barrier residue thickness and metal residue thickness. The data is then inputted into an algorithm and polishing parameter outputs are calculated. The outputs are sent to the CMP station and used to supplement or replace the previous polishing parameters. Subsequent wafers are polished on the CMP station using the revised polishing parameters.
Claims34
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- measuring a dielectric thickness in an array of a first wafer from a plurality of wafers at a metrology station;
- determining at least one polishing parameter from the dielectric thickness in the array of the first wafer;
- and
- polishing a subsequent wafer from the plurality of wafers using the polishing parameter.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- measuring at a metrology station metal feature thicknesses at multiple points across a first wafer wherein the first wafer is one of a plurality of wafers;
- calculating at least one polishing parameter using the measurements of the metal feature thicknesses of the first wafer that approximates an optimal solution under a plurality of constraints with reference to which a predicted metal feature thickness uniformity is maximized in a subsequent wafer from the plurality of wafers;
- and
- polishing the subsequent wafer from the plurality of wafers using the at least one polishing parameter.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- polishing a first wafer from a plurality of wafers on a chemical mechanical polishing apparatus using a set of polishing parameters;
- measuring the profile of the first polished wafer at a metrology station, the profile including at least a first measurement of dielectric thickness in a first array, a second measurement of dielectric thickness in a second array, a first measurement of dielectric thickness in a first field, and a second measurement of dielectric thickness in a second field, where the first array is proximate to the first field and the second field is proximate to the second array;
- determining a first erosion measurement and a second erosion measurement, where the first erosion measurement is a difference between the first dielectric thickness in the first field and the first dielectric thickness in the first array and the second erosion measurement is a difference between the second dielectric thickness in the second field and the second dielectric thickness in the second array;
- calculating a new polishing parameter from the measurement of the profile of the first wafer using the first and second dielectric thicknesses in the first and second arrays and the first and second erosion measurements;
- communicating the new polishing parameter to the chemical mechanical polishing apparatus;
- and
- using the new polishing parameter to polish a subsequent wafer.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- measuring a first dielectric thickness in a first array of a first wafer at a metrology station;
- measuring a second dielectric thickness in a second array of the first wafer at the metrology station;
- passing the first and second dielectric thicknesses from the metrology station to a controller;
- determining in the controller at least one polishing parameter in the controller using the first and second dielectric thicknesses;
- and
- polishing a subsequent wafer with the at least one polishing parameter.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- measuring metal residue and barrier material residue on a first wafer, where the metal residue and the barrier material residue are located on field dielectric material, array dielectric material and metal features;
- calculating at least one polishing parameter using the metal residue and the barrier material residue measurements, where the at least one polishing parameter ensures complete removal of the metal residue and the barrier material residue in a second wafer;
- and
- polishing the second wafer using the at least one polishing parameter.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- measuring at a metrology station metal feature thicknesses at multiple points across a first wafer wherein the first wafer is one of a plurality of wafers;
- calculating at least one polishing parameter using the measurements of the metal feature thicknesses of the first wafer that approximates an optimal solution under a plurality of constraints with reference to which a difference between a predicted metal feature thickness and a target metal feature thickness is minimized;
- and
- polishing a subsequent wafer from the plurality of wafers using the at least one polishing parameter.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- measuring a barrier layer residue thickness of a first substrate from a plurality of substrates at a metrology station;
- determining at least one polishing parameter from the barrier layer residue thickness of the first substrate;
- and
- polishing a subsequent substrate from the plurality of substrates using the polishing parameter.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- polishing a first substrate from a plurality of substrates on a chemical mechanical polishing apparatus using a set of polishing parameters;
- measuring the profile of the first polished substrate at a metrology station, the profile including at least one measurement selected from the group consisting of a measurement of dielectric thickness in an array and a measurement of barrier layer residue thickness;
- determining a new polishing parameter from the measurement of the profile of the first substrate;
- communicating the new polishing parameter to the chemical mechanical polishing apparatus;
- and
- using the new polishing parameter to polish a subsequent substrate.
A method for closed loop control in chemical mechanical polishing using an inline metrology station, comprising:
- measuring a metal feature thickness in an array of a first substrate from a plurality of substrates at a metrology station;
- determining at least one polishing parameter from the metal feature thickness in the array of the first substrate;
- and
- polishing a subsequent substrate from the plurality of substrates using the polishing parameter.
Dependencies are inferred from the claim text.