Method and apparatus for optically analyzing a surface
AssigneeKLA-Tencor Corporation
InventorsKlaus Freischlad, Shouhong Tang
Life of this patent
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Abstract
In one embodiment, a system to measure defects on a surface of a wafer and an edge of the wafer using a single tool comprises a radial motor to move an optical head in a radial direction to detect defects at locations displaced from the edge of the wafer, and a rotational motor to rotate the optical head around the edge of the wafer to detect defects on the edge of the wafer.
Claims30
A system to analyze surface characteristics of a test object using broadband light scanning interferometry, comprising:
- an interferometer system to acquire data from a scanning interferometry signal from a surface location of a test object;
- and
- a processing system to:
- transform the acquired data to an n-dimensional function comprising an independent frequency variable and an independent time variable;
- divide the time variable signal into a plurality of time-differentiated segments;
- divide the frequency variable into a plurality of time differentiated segments corresponding to the plurality of time differentiated segments of the time domain signal;
- compare the transformed n-dimensional function with a set of models to determine a best match from the comparison;
- and
- use the plurality of time differentiated segments of the frequency variable signal and the plurality of time differentiated segments of the time variable signal to construct the n-dimensional function as a function of time.
A system to analyze surface characteristics of a test object using broadband light scanning interferometry, comprising:
- an interferometer system to acquire data from a scanning interferometry signal from a surface location of a test object;
- and
- a processing system to:
- transform the acquired data to an n-dimensional function having an independent scale variable and an independent time variable;
- and
- compare the transformed n-dimensional function with a set of stored n-dimensional function models to determine a best match from the comparison.
A system to analyze surface characteristics of a test object using broadband light scanning interferometry, comprising:
- an interferometer system comprising a broadband light beam to vertically scan a position on the surface of the test object and to generate an interferometry signal comprising a time domain signal at selected unique times during the vertical scanning;
- and
- a processing system to:
- apply a time differentiated function to the interferometry signal to obtain a frequency domain signal;
- divide the time domain signal into a plurality of time-differentiated segments;
- and
- construct a multi-domain function from the frequency domain signal and the time domain signal.
Dependencies are inferred from the claim text.