Kla Tencor Corporation

Tencor Instruments

Kla-Tencor Technologies Corporation

Gazillion Bits, Inc.

Xing Chen

Jean-Louis Stehle

Timothy R Piwonka-Corle

Dorian Zahorski

Lloyd J Lacomb, Jr

Karen F Scoffone

Jennming Chen

Mehrdad Nikoonahad

Shing Lee

Hwan J Jeong

Philip D Flanner, Iii

Jean-Pierre Rey

Joseph R Carter

John-Pierre Rey

Kiron B Malwankar

An optical interleaver is described, comprising a splitting element for splitting an incident beam into a first optical signal directed along a first path and a second optical signal directed along a second path, a first resonant element positioned along the first path, a second resonant element positioned along the second path, and a combining element positioned to receive and to interferometrically combine the outputs of the first and second resonant to produce the output signal. The optical interleaver may be implemented using a free-space configuration using a beamsplitter and a plurality of resonant cavities such as asymmetric Fabry-Perot resonators or Michelson-Gires-Tournois resonators. In an alternative preferred embodiment, the optical interleaver may be implemented in a Mach-Zender-style configuration using couplers and fiber ring resonators.

Optical interleaving with enhanced spectral response and reduced polarization sensitivity

A method and system for spectroscopic ellipsometry employing reflective optics to measure a small region of a sample by reflecting radiation (preferably broadband UV, visible, and near infrared radiation) from the region. The system preferably has an autofocus assembly and a processor programmed to determine from the measurements the thickness and/or complex refractive index of a thin film on the sample. Preferably, only reflective optics are employed along the optical path between the polarizer and analyzer, a sample beam reflects with low incidence angle from each component of the reflective optics, the beam is reflectively focused to a small, compact spot on the sample at a range of high incidence angles, and an incidence angle selection element is provided for selecting for measurement only radiation reflected from the sample at a single, selected angle (or narrow range of angles). The focusing mirror preferably has an elliptical shape to reduce off-axis aberrations in the focused beam. Some embodiments include both a spectrophotometer and an ellipsometer integrated together as a single instrument. In such instrument, the spectrophotometer and ellipsometer share a radiation source, and radiation from the source can be focused by either the spectrophotometer or the ellipsometer to the same focal point on a sample. Preferred embodiments of the ellipsometer employ a rotating, minimal-length Rochon prism as a polarizer, and include a spectrometer with an intensified photodiode array to measure reflected radiation from the sample, and a reference channel (in addition to a sample channel which detects radiation reflected from the sample).

Focused beam spectroscopic ellipsometry method and system

The surface of a doped semiconductor wafer is heated locally by means of a pump beam whose intensity is modulated at a first frequency. The heated area is sampled by a probe beam whose intensity is modulated at a second frequency. After the probe beam has been modulated (reflected or transmitted) at the first frequency by the wafer, the modulated probe beam is detected at a frequency equal to the difference between the harmonics of the first and second frequencies to determine dose of the dopants in the wafer. Such or similar type of instrument for measuring dose may be combined with an ellipsometer, reflectometer or polarimeter for measuring dose as well as thickness(es) and/or indices of refraction in a combined instrument for measuring the same sample.

System for non-destructive measurement of samples

The pixel position-to-wavelength calibration function of film measurement devices such as spectroscopic ellipsometers and spectroreflectometers may shift due to temperature and humidity changes and mechanical factors. One or more wavelength markers provided by the light source or reference sample may be used to correct the calibration function. The pixel positions of one or more persistent wavelength markers are noted during the calibration process and the current positions of such markers are again noted to account for shifts due to various factors to correct the calibration function.

Film measurement system with improved calibration

A method and system for spectroscopic ellipsometry employing reflective optics to measure a small region of a sample by reflecting radiation (preferably broadband UV, visible, and near infrared radiation) from the region. The system preferably has an autofocus assembly and a processor programmed to determine from the measurements the thickness and/or complex refractive index of a thin film on the sample. Preferably, only reflective optics are employed along the optical path between the polarizer and analyzer, a sample beam reflects with low incidence angle from each component of the reflective optics, the beam is reflectively focused to a small, compact spot on the sample at a range of high incidence angles, and an incidence angle selection element is provided for selecting for measurement only radiation reflected from the sample at a single, selected angle (or narrow range of angles). The focusing mirror preferably has an elliptical shape,to reduce off-axis aberrations in the focused beam. Some embodiments include both a spectrophotometer and an ellipsometer integrated together as a single instrument. In such instrument, the spectrophotometer and ellipsometer share a radiation source, and radiation from the source can be focused by either the spectrophotometer or the ellipsometer to the same focal point on a sample. Preferred embodiments of the ellipsometer employ a rotating, minimal-length Rochon prism as a polarizer, and include a spectrometer with an intensified photodiode array to measure reflected radiation from the sample, and a reference channel (in addition to a sample channel which detects radiation reflected from the sample).

A method for calibrating an ellipsometer, and an ellipsometer including a processor programmed to control the analyzer, polarizer, and other ellipsometer components, and to process the data measured by the ellipsometer to perform the calibration method automatically. Where the ellipsometer's polarizer rotates and the analyzer remains fixed during measurement, the method determines coarse approximations of values A.sub.0 and P.sub.0, and then processes reflectivity data obtained at two or more analyzer angles to determine refined approximations of the values A.sub.0 and P.sub.0, where P.sub.0 is the angle of the polarizer's optical axis at an initial time, and A.sub.0 is the offset of the actual orientation angle of the analyzer from a nominal analyzer angle. Preferably the ellipsometer is a spectroscopic ellipsometer, the reflectivity data determine a tan.psi. spectrum and a cos.DELTA. spectrum for each of the analyzer angles, and the coarse approximations of A.sub.0 and P.sub.0 are refined by processing the reflectivity data by performing regression on A.sub.0 and P.sub.0 until the differences among the tan.psi. and cos.DELTA. spectra for several analyzer angles are minimized. Where the ellipsometer's analyzer rotates and the polarizer remains fixed during measurement, the method coarsely determines values A'.sub.0 and P'.sub.0, and then processes reflectivity data obtained at two or more polarizer angles to determine refined approximations of the values A'.sub.0 and P'.sub.0, where P'.sub.0 is the angle of the analyzer's optical axis at an initial time, and A'.sub.0 is the offset of the actual orientation angle of the polarizer from a nominal polarizer angle.

Method and system for calibrating an ellipsometer

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San Jose, CA, United States of America

Xing Chen