Developer endpoint detection in a track lithography system
AssigneeApplied Materials, Inc.
InventorHarald Herchen
Life of this patent
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Abstract
A method of detecting developer endpoint. The method includes illuminating a device region of a substrate with a first optical beam prior to initiating a development stage of processing and detecting a baseline optical signal reflected from the device region of the substrate. The method also includes illuminating the device region of the substrate with a second optical beam during a development stage of processing and detecting an endpoint optical signal reflected from the device region of the substrate. The method further includes comparing the baseline optical signal to the endpoint optical signal and determining a developer endpoint based on the comparing step.
Claims21
A method of detecting developer endpoint, the method comprising:
- illuminating a device region of a substrate with a first optical beam prior to initiating a development stage of processing;
- detecting a baseline optical signal reflected from the device region of the substrate;
- illuminating the device region of the substrate with a second optical beam during a development stage of processing;
- detecting an endpoint optical signal reflected from the device region of the substrate;
- comparing the baseline optical signal to the endpoint optical signal;
- and
- determining a developer endpoint based on the comparing step.
A method of detecting developer endpoint, the method comprising:
- illuminating a device region of a substrate with a first optical beam inclined at a first angle of incidence;
- illuminating the device region of the substrate with a second optical beam inclined at substantially normal incidence;
- detecting an optical signal associated with the first optical beam using a first detector;
- detecting a calibration signal associated with the second optical beam;
- and
- adjusting a position of the optical signal at the first detector based on the calibration signal.
A developer endpoint system comprising:
- a first optical source producing an optical beam propagating along a first optical path inclined at a non-zero angle to and reflecting and diffracting off a device region of a substrate;
- a first detector coupled to a first reflection path, the first reflection path impinging on the first detector at a first position, the first detector adapted to output a first signal;
- a second detector coupled to a first diffraction path, the first diffraction path impinging on the second detector at a second position, the second detector adapted to output a second signal;
- and
- a processor adapted to
- determine a baseline signal computed from the first signal and the second signal, and
- determine an endpoint signal computed from the first signal and the second signal.
A develop module including a developer endpoint detection system, the develop module comprising:
- a develop chamber;
- a rotatable substrate support chuck adapted to support a semiconductor substrate;
- at least one dispense nozzle adapted to dispense a developer solution onto a surface of the semiconductor substrate;
- a develop bowl adapted to collect developer solution spun off the surface of the semiconductor substrate;
- a first optical source producing an optical beam propagating along a first optical path inside the develop chamber, the first optical source inclined at a non-zero angle with respect to the semiconductor substrate;
- a first detector coupled to a first reflection path inside the develop chamber, the first reflection path impinging on the first detector at a first position, the first detector adapted to output a first signal;
- and
- a second detector coupled to a first diffraction path inside the chamber, the first diffraction path impinging on the second detector at a second position, the second detector adapted to output a second signal.
Dependencies are inferred from the claim text.