| US 7,502,104 B2 | ||
| Probe beam profile modulated optical reflectance system and methods | ||
| Alex Salnik, Castro Valley, Calif. (US); Lena Nicolaides, Castro Valley, Calif. (US); and Jon Opsal, Livermore, Calif. (US) | ||
| Assigned to KLA-Tencor Corporation, Milpitas, Calif. (US) | ||
| Filed on Aug. 06, 2007, as Appl. No. 11/890,712. | ||
| Claims priority of provisional application 60/836763, filed on Aug. 10, 2006. | ||
| Prior Publication US 2008/0036998 A1, Feb. 14, 2008 | ||
| Int. Cl. G01N 21/00 (2006.01) | ||
| U.S. Cl. 356—237.2 [356/237.5] | 24 Claims |
| 1. An apparatus for evaluating a sample comprising:
an intensity modulated energy source for periodically exciting the sample;
a probe beam of radiation;
a first optical element for focusing the probe beam onto the sample within a region which has been periodically excited and
in a manner so that the rays within the probe beam create a spread of angles of incidence;
a detector array for monitoring the reflected probe beam;
a second optical element for relaying an image of the sample from the focal plane of the first optical element to said detector
array with said detector array simultaneously generating a plurality of output signals corresponding to the modulated intensity
of the probe beam at a plurality of different angles of incidence; and
a processor for evaluating properties of a sample based on the output signals.
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