Kla Tencor Corporation

Kla Corporation

Sandia Corporation

Guorong Vera Zhuang

Shankar Krishnan

David Y Wang

John Fielden

Andrei V Shchegrov

Leonid Poslavsky

Michael S Bakeman

Johannes D De Veer

Gildardo Rios Delgado

Xuefeng Liu

Derrick A Shaughnessy

Klaus Flock

Ady Levy

Christopher F Bevis

Walter Dean Mieher

John Josef Hench

Steven Russel Spielman

Daniel C Wack

Leonard Elliott Klebanoff

Kevin A Peterlinz

Lanhua Wei

Lawrence D Rotter

Haiming Wang

Jonathan M Madsen

Dawei Hu

Paul Aoyagi

Mengmeng Ye

Karl R Umstadter

Jeromy T Hollenshead

Elena Starodub

A system includes a light source, a Fourier transform infrared reflectometer (FTIR) spectrometer, and broadband reflectometer optics. The system is configured to measure polarized light and unpolarized reflectivities in a wavelength range from 2 &#x3bc;m to 20 &#x3bc;m. The light source can be a laser-driven light source. The spectroscopic reflectometer can include a single channel or two channels.

Multi-environment polarized infrared reflectometer for semiconductor metrology

Methods and systems for performing high throughput spectroscopic measurements of semiconductor structures at mid-infrared wavelengths are presented herein. A Fourier Transform Infrared (FTIR) spectrometer includes one or more measurement channels spanning a wavelength range between 2.5 micrometers and 12 micrometers. The FTIR spectrometer measures a target at multiple different angles of incidence, azimuth angles, different wavelength ranges, different polarization states, or any combination thereof. In some embodiments, illumination light is provided by a laser sustained plasma (LSP) light source to achieve high brightness and small illumination spot size. In some embodiments, FTIR measurements are performed off-axis from the direction normal to the surface of the wafer. In some embodiments, a Stirling cooler extracts heat from the detector of an FTIR spectrometer. In another aspect, measurements performed by one or more spectrometer measurement channels are combined with measurements performed by a mid-infrared FTIR spectrometer channel to characterize high aspect ratio structures.

Mid-infrared spectroscopy for measurement of high aspect ratio structures

Methods and systems are described herein for producing high radiance illumination light for use in semiconductor metrology based on a confined, sustained plasma. One or more plasma confining circuits introduce an electric field, a magnetic field, or a combination thereof to spatially confine a sustained plasma. The confinement of the sustained plasma decreases the size of the induced plasma resulting in increased radiance. In addition, plasma confinement may be utilized to shape the plasma to improve light collection and imaging onto the specimen. The induced fields may be static or dynamic. In some embodiments, additional energy is coupled into the confined, sustained plasma to further increase radiance. In some embodiments, the pump energy source employed to sustained the plasma is modulated in combination with the plasma confining circuit to reduce plasma emission noise.

Confined illumination for small spot size metrology

Methods and systems for performing broadband spectroscopic metrology with reduced sensitivity to focus errors are presented herein. Significant reductions in sensitivity to focus position error are achieved by imaging the measurement spot onto the detector such that the direction aligned with the plane of incidence on the wafer surface is oriented perpendicular to the direction of wavelength dispersion on the detector surface. This reduction in focus error sensitivity enables reduced focus accuracy and repeatability requirements, faster focus times, and reduced sensitivity to wavelength errors without compromising measurement accuracy. In a further aspect, the dimension of illumination field projected on the wafer plane in the direction perpendicular to the plane of incidence is adjusted to optimize the resulting measurement accuracy and speed based on the nature of target under measurement.

Optical metrology with reduced focus error sensitivity

Disclosed are apparatus and methods for performing small angle x-ray scattering metrology. This system includes an x-ray source for generating x-rays and illumination optics for collecting and reflecting or refracting a portion of the generated x-rays towards a particular focus point on a semiconductor sample in the form of a plurality of incident beams at a plurality of different angles of incidence (AOIs). The system further includes a sensor for collecting output x-ray beams that are scattered from the sample in response to the incident beams on the sample at the different AOIs and a controller configured for controlling operation of the x-ray source and illumination optics and receiving the output x-rays beams and generating an image from such output x-rays.

Small-angle scattering X-ray metrology systems and methods

Methods and systems for realizing a high brightness liquid metal droplet based x-ray source suitable for high throughput x-ray metrology are presented herein. A high power laser bombards a solid target material to generate liquid metal droplets. The laser generated liquid metal droplets are excited with a focused, high power excitation beam such as an electron or laser beam. The excitation beam is synchronized with the stream of liquid metal droplets stimulated by the high power laser to achieve a stable x-ray emission generated by the excited liquid metal droplets. In some embodiments, x-ray optics are designed to efficiently collect and focus radiation within a desired emission band onto a measurement target. Reliability is improved by shielding the excitation source and the x-ray optics from the region of interaction between the excitation beam and the liquid metal droplet anode by a localized curtain of shielding gas.

High brightness liquid droplet X-ray source for semiconductor metrology

Methods and systems for performing broadband spectroscopic metrology with reduced sensitivity to grating anomalies are presented herein. A reduction in sensitivity to grating anomalies is achieved by selecting a subset of available system parameter values for measurement analysis. The reduction in sensitivity to grating anomalies enables an optimization of any combination of precision, sensitivity, accuracy, system matching, and computational effort. These benefits are particularly evident in optical metrology systems having large ranges of available azimuth angle, angle of incidence, illumination wavelength, and illumination polarization. Predictions of grating anomalies are determined based on a measurement model that accurately represents the interaction between the measurement system and the periodic metrology target under measurement. A subset of available system parameter values is selected to reduce the impact of grating anomalies on measurement results. The selected subset of available system parameters is implemented on a configurable spectroscopic metrology system performing measurements.

Optical metrology with reduced sensitivity to grating anomalies

The present invention may include an illumination source configured to illuminate a surface of a sample, a detector configured to detect at least a portion of light reflected from the surface of the sample, a selectably configurable optical system comprising: a rotatable polarizing element disposed in the illumination arm of the optical system, an analyzing element disposed in the collection arm of the optical system, and a rotatable-translatable compensator element disposed in the collection arm of the optical system, and a control system communicatively configured to selectably configure the optical system in the a rotating compensator (RCSE) mode, a rotating polarizer (RPSE) mode, or a rotating polarizer and compensator (RPRC) mode.

Selectably configurable multiple mode spectroscopic ellipsometry

The present invention may include an illumination source, a detector, a selectably adjustable optical system including a dynamically adjustable illumination pupil of the illumination arm, a dynamically adjustable collection pupil of the collection arm, a dynamically adjustable illumination field stop of the illumination arm, a dynamically adjustable collection field stop of the collection arm, a sensor configured to measure one or more optical characteristics of one or more components of the optical system, and a control system configured to selectably dynamically adjust at least one of the illumination pupil, the collection pupil, the illumination field stop, the collection field stop, and a spectral radiance of the illumination source.

Dynamically adjustable semiconductor metrology system

An optical instrument, including a chamber, an object exposed to an interior of the chamber, a source of low-pressure gas, the gas comprising at least one of low-pressure molecular hydrogen gas, low-pressure molecular oxygen and a low-pressure noble gas, the source of low pressure gas being fluidly coupled to the chamber, a low voltage source electrically coupled between the object and a remaining portion of the instrument that is exposed to the interior of the chamber so as to maintain the object at a low voltage relative to the remaining portion, and an EUV/VUV light source adapted to direct EUV/VUV light through the low pressure gas in the chamber onto the object. In such a system, when the EUV/VUV light source is activated ions of the low-pressure gas are formed and directed to the object. The ions may be ions of Hydrogen, Oxygen or a noble gas.

Methods and apparatus for cleaning objects in a chamber of an optical instrument by generating reactive ions using photon radiation

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.

Light source tracking in optical metrology system

An apparatus for purifying a controlled-pressure environment in a chamber, including: a piece of lithium-aluminum alloy located in the chamber; an activation element arranged to impart energy to the piece of lithium-aluminum alloy to sublimate lithium from the piece of lithium-aluminum alloy; a feedback control system including a sensor system arranged to measure a condition within the chamber, and a controller in communication with the sensor and configured to control operation of the activation element according to an evaluation of the condition; and a collection plate located in the chamber and arranged to form a layer of the sublimated lithium on a surface of the collection plate.

Apparatus for purifying a controlled-pressure environment

A method to calibrate a polarizer in polarized optical system at any angle of incidence, by decoupling the calibration from a polarization effect of the system, by providing a calibration apparatus that includes a substrate having a polarizer disposed on a surface thereof, with an indicator on the substrate for indicating a polarization orientation of the polarizer, loading the calibration apparatus in the polarized optical system with the indicator in a desired position, determining an initial angle between the polarization orientation and a reference of the polarized optical system, acquiring spectra using the polarized optical system at a plurality of known angles between the polarization orientation and the reference of the polarized optical system, using the spectra to plot a curve indicating an angle of the polarizer in the polarized optical system, and when the angle of the polarizer is outside of a desired range, adjusting the angle of the polarizer, and repeating the steps of acquiring the spectra, and plotting a curve indicating the angle of the polarizer.

Optical system polarizer calibration

Line edge roughness or line width roughness of a feature on a sample may be determined from incident radiation scattered from the feature. An amount of ordered scattered radiation characterized by a discrete diffraction order is determined and a diffuse scattered radiation signal is measured. A ratio between an intensity of the ordered scattered incident radiation and an intensity of the diffuse scattered radiation signal is determined. The line edge roughness or line width roughness is determined from the ratio.

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San Jose, CA, United States of America

Guorong Vera Zhuang