Title:
SYSTEM FOR ANALYZING SURFACE CHARACTERISTICS WITH SELF-CALIBRATING CAPABILITY
Document Type and Number:
WIPO Patent Application WO2000065331
Kind Code:
A9
Abstract:
Two phase modulators or polarizing elements are employed to modulate the polarization of an interrogating radiation beam before and after the beam has been modified by a sample to be measured. The detected signal may be used to derive ellipsometric and system parameters, such as parameters related to the angle of fixed polarizing elements and retardances of phase modulators. A portion of the radiation may be diverted for detecting sample tilt or a change in sample height. A cylindrical objective may be used for focusing the beam onto the sample to illuminate a circular spot on the sample. The above-described self-calibrating ellipsometer may be combined with another optical measurement instrument such as a polarimeter, a spectroreflectometer or another ellipsometer to improve the accuracy of measurement and/or to provide calibration standards for the optical measurement instrument. The self-calibrating ellipsometer as well as the combined system may be used for measuring sample characteristics such as film thickness and depolarization of radiation caused by the sample.
Inventors:
WANG HAIMING
MAXTON PATRICK M
JOHNSON KENNETH C
NIKOONAHAD MEHRDAD
MAXTON PATRICK M
JOHNSON KENNETH C
NIKOONAHAD MEHRDAD
Application Number:
PCT/US2000/010875
Publication Date:
June 13, 2002
Filing Date:
April 21, 2000
Export Citation:
Assignee:
KLA TENCOR CORP (US)
International Classes:
G01B11/00; G01B11/06; G01B11/26; G01J3/02; G01J3/447; G01J4/04; G01N21/21; G01N21/27; G01N21/41; (IPC1-7): G01N21/21; G01B11/06
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