Method and apparatus for determining an etch endpoint
AssigneeAdvanced Micro Devices, Inc.
InventorsTodd P. Lukanc, Ercan Adem
Life of this patent
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Abstract
An apparatus and method for detecting an endpoint for an etching process utilize a reaction chamber with an ion source and detector placed within the reaction chamber. The ion source directs a primary beam of ions towards a wafer so that the ion beam impacts the top layer of the wafer. A detector detects primary ions reflected from the wafer and secondary ions scattered from the wafer. A value is determined that corresponds to the amount of reflected and scattered ions. A change in the value indicates that the ion beam is impacting a layer beneath the top layer of the wafer, and signifies the reaching of the etch process endpoint.
Claims20
An apparatus for detecting an endpoint of an etch process comprising:
- a reaction chamber;
- a plasma source;
- an ion source positioned to emit ions into the reaction chamber;
- an ion detector positioned to detect ions in the reaction chamber, the ion detector detecting ions emitted from the ion source and reflected off a wafer located in the reaction chamber, and generates a signal based upon detected ions;
- and
- a signal processor coupled to the detector that determines a value based upon the signal from the ion detector.
A method for detecting an endpoint of an etch process, comprising the steps of:
- generating a plasma;
- emitting ions from a source towards a wafer within a reaction chamber;
- detecting ions within the reaction chamber after the ions from the source have impacted the wafer;
- creating a signal based upon the detected ions;
- determining a value for the detected ions based upon the signal;
- etching the wafer;
- monitoring the value while the wafer is etched;
- and
- indicating the etch endpoint when the value changes to a second value.
A metal deposition system, comprising:
- a vacuum chamber;
- an etch station within the vacuum chamber;
- a plasma source at the etch station;
- an ion source at the etch station;
- an ion detector at the etch station, the ion detector detects ions emitted from the ion source and reflected off a wafer located at the etch station, and generates a signal based upon detected ions and;
- a signal processor coupled to the detector that determines a value based upon the signal from the detector.
Dependencies are inferred from the claim text.