Klaus Flock

US Patent:

7889340, Feb 15, 2011

Filed:

Jul 9, 2008

Appl. No.:

12/170371

Inventors:

Klaus Flock - Mountain View CA, US
Jeff T. Fanton - Los Altos CA, US

Assignee:

KLA-Tencor Corporation - San Jose CA

International Classification:

G01J 4/00

US Classification:

356369, 356364, 356365, 356366, 356367, 356368

Abstract:

In embodiments of the present invention a second, different waveplate is introduced into a single rotating compensator normal incidence ellipsometer. The second waveplate provides a quarter wavelength retardation that is different from and complementary to that of the first waveplate in order to increase the spectral range for which useful retardation is available, especially towards the deep UV spectrum. The sensitivity for the system may also be increased in the conventional spectral range, since each of the two waveplates may be optimized for its own, somewhat more narrow spectral range of operation. With the proper choice of two waveplates of different retardation, the useful spectral range may be extended from typically 190-820 nm to 150-1000 nm, and beyond if necessary, while increasing the sensitivity within the conventional wavelength range at the same time.

US Patent:

7889339, Feb 15, 2011

Filed:

Jul 9, 2008

Appl. No.:

12/170367

Inventors:

Klaus Flock - Mountain View CA, US
Jeff T. Fanton - Los Altos CA, US

Assignee:

KLA-Tencor Corporation - San Jose CA

International Classification:

G01J 4/00

US Classification:

356369, 356364, 356365, 356366, 356367, 356368

Abstract:

Ellipsometry using two waveplates of complementary retardation in a dual rotating compensator configuration is disclosed. Two waveplates of complementary retardation may be used to increase the useful spectral range of a rotating compensator ellipsometer, in particular towards the deep Ultraviolet (UV) spectrum. The improved rotating compensating ellipsometer disclosed herein enables a user to select specific and different waveplate retardations for the purpose of increasing the operating wavelength range of the rotating compensating ellipsometer.

US Patent:

20170052112, Feb 23, 2017

Filed:

Nov 7, 2016

Appl. No.:

15/344704

Inventors:

- Milpitas CA, US
Klaus Flock - Sunnyvale CA, US
Muzammil Arain - Milpitas CA, US
David Y. Wang - Santa Clara CA, US

International Classification:

G01N 21/23
G01N 21/21
G01N 21/95
G02B 5/30

Abstract:

A rotatable compensator configured to transmit non-collimated light over a broad range of wavelengths, including ultraviolet, with a high degree of retardation uniformity across the aperture is presented. In one embodiment, a rotatable compensator includes a stack of four individual plates in optical contact. The two thin plates in the middle of the stack are made from a birefringent material and are arranged to form a compound, zeroth order bi-plate. The remaining two plates are relatively thick and are made from an optically isotropic material. These plates are disposed on either end of the compound, zeroth order bi-plate. The low order plates minimize the sensitivity of retardation across the aperture to non-collimated light. Materials are selected to ensure transmission of ultraviolet light. The optically isotropic end plates minimize coherence effects induced at the optical interfaces of the thin plates.

US Patent:

20150285735, Oct 8, 2015

Filed:

Jun 19, 2015

Appl. No.:

14/745047

Inventors:

- Milpitas CA, US
Klaus Flock - Sunnyvale CA, US
Lawrence Rotter - Pleasanton CA, US
Shankar Krishnan - Santa Clara CA, US
Johannes D. de Veer - Menlo Park CA, US
Catalin Filip - Pleasanton CA, US
Gregory Brady - Campbell CA, US
Muzammil Arain - Milpitas CA, US
Andrei Shchegrov - Campbell CA, US

Assignee:

KLA- Tencor Corporation - Milpitas CA

International Classification:

G01N 21/21
G01N 21/95

Abstract:

An apparatus includes (i) a bright light source for providing an illumination beam at multiple wavelengths selectable with a range from a deep ultraviolet wavelength to an infrared wavelength, (ii) illumination optics for directing the illumination beam towards a sample at selectable sets of angles of incidence (AOI's) or azimuth angles (AZ's) and polarization states to provide spectroscopic ellipsometry, wherein the illumination optics include an apodizer for controlling a spot size of the illumination beam on the sample at each of the selectable AOI/AZ sets, (iii) collection optics for directing an output beam from the sample in response to the illumination beam at each of the selectable AOI/AZ sets and polarization states towards a detector that generates an output signal or image based on the output beam, and (v) a controller for characterizing a feature of the sample based on the output signal or image.

US Patent:

20150055123, Feb 26, 2015

Filed:

Aug 22, 2014

Appl. No.:

14/466369

Inventors:

- Milpitas CA, US
Klaus Flock - Sunnyvale CA, US
Muzammil Arain - Milpitas CA, US
David Y. Wang - Santa Clara CA, US

International Classification:

G02B 5/30
G01N 21/21
G01J 1/42

US Classification:

356 51, 35948902

Abstract:

A rotatable compensator configured to transmit non-collimated light over a broad range of wavelengths, including ultraviolet, with a high degree of retardation uniformity across the aperture is presented. In one embodiment, a rotatable compensator includes a stack of four individual plates in optical contact. The two thin plates in the middle of the stack are made from a birefringent material and are arranged to form a compound, zeroth order bi-plate. The remaining two plates are relatively thick and are made from an optically isotropic material. These plates are disposed on either end of the compound, zeroth order bi-plate. The low order plates minimize the sensitivity of retardation across the aperture to non-collimated light. Materials are selected to ensure transmission of ultraviolet light. The optically isotropic end plates minimize coherence effects induced at the optical interfaces of the thin plates.

US Patent:

20140375981, Dec 25, 2014

Filed:

Oct 1, 2013

Appl. No.:

14/043783

Inventors:

- Milpitas CA, US
Klaus Flock - Sunnyvale CA, US
Lawrence Rotter - Pleasanton CA, US
Shankar Krishnan - Santa Clara CA, US
Johannes D. de Veer - Menlo Park CA, US
Catalin Filip - Pleasanton CA, US
Gregory Brady - Campbell CA, US
Muzammil Arain - Milpitas CA, US
Andrei Shchegrov - Campbell CA, US

Assignee:

KLA-Tencor Corporation - Milpitas CA

International Classification:

G01N 21/88

US Classification:

356 51

Abstract:

An apparatus includes (i) a bright light source for providing an illumination beam at multiple wavelengths selectable with a range from a deep ultraviolet wavelength to an infrared wavelength, (ii) illumination optics for directing the illumination beam towards a sample at selectable sets of angles of incidence (AOI's) or azimuth angles (AZ's) and polarization states to provide spectroscopic ellipsometry, wherein the illumination optics include an apodizer for controlling a spot size of the illumination beam on the sample at each of the selectable AOI/AZ sets, (iii) collection optics for directing an output beam from the sample in response to the illumination beam at each of the selectable AOI/AZ sets and polarization states towards a detector that generates an output signal or image based on the output beam, and (v) a controller for characterizing a feature of the sample based on the output signal or image.

US Patent:

20140166862, Jun 19, 2014

Filed:

Dec 11, 2013

Appl. No.:

14/103635

Inventors:

- Milpitas CA, US
Klaus Flock - Sunnyvale CA, US

International Classification:

G01N 21/95

US Classification:

2502082

Abstract:

Methods and systems for enhancing the throughput of a metrology system generating measurement signals based on at least two different optical properties of the illumination light are presented. A detector having a two dimensional photosensitive area is subdivided into multiple photosensitive stripes by multiple, independent linear arrays of shift register elements located within the photosensitive area. Charge transfer from pixels within each stripe is directed to a distinct linear array of shift register elements. Each photosensitive stripe is able to resolve an optical property dispersed across the length of each stripe with relatively high resolution. In addition, the detector is able to resolve another optical property dispersed across several photosensitive stripes in a direction orthogonal to each linear array of shift registers at a relatively low resolution.

US Patent:

20130033704, Feb 7, 2013

Filed:

Oct 31, 2011

Appl. No.:

13/285712

Inventors:

Guorong V. Zhuang - Santa Clara CA, US
Shankar Krishnan - Santa Clara CA, US
Johannes D. de Veer - Menlo Park CA, US
Klaus Flock - Mountainview CA, US
David Y. Wang - Santa Clara CA, US
Lawrence D. Rotter - Pleasanton CA, US

Assignee:

KLA-TENCOR CORPORATION - Milpitas CA

International Classification:

G01C 1/00

US Classification:

356138

Abstract:

The present invention may include loading a diagnostic sample onto a sample stage, focusing light from an illumination source disposed on a multi-axis stage onto the diagnostic sample, collecting a portion of light reflected from a surface of the diagnostic sample utilizing a detector, wherein the illumination source and the detector are optically direct-coupled via an optical system, acquiring a set of diagnostic parameters indicative of illumination source position drift from the diagnostic sample, determining a magnitude of the illumination source position drift by comparing the acquired set of diagnostic parameters to an initial set of parameters obtained from the diagnostic sample at a previously measured alignment condition, determining a direction of the illumination source position drift; and providing illumination source position adjustment parameters configured to correct the determined magnitude and direction of the illumination source position drift to the multi-axis actuation control system of the multi-axis stage.