Kla Tencor Corporation

Kla Corporation

Kerstin Purrucker

Alexander Buettner

Noam Sapiens

David Y Wang

Kevin A Peterlinz

Shankar Krishnan

Andrei V Shchegrov

Michael Friedmann

Methods and systems for performing measurements of semiconductor structures based on high-brightness, Soft X-Ray (SXR) illumination over a small illumination spot size with a small physical footprint are presented herein. In one aspect, the focusing optics of an SXR based metrology system project an image of the illumination source onto a specimen under measurement with a demagnification of at least 1.25. In a further aspect, an illumination beam path from the x-ray illumination source to the specimen under measurement is less than 2 meters. In another aspect, SXR based measurements are performed with x-ray radiation in the soft x-ray region (i.e., 80-3000 eV). In some embodiments, SXR based measurements are performed at grazing angles of incidence in a range from near zero degrees to 90 degrees. In some embodiments, the illumination optics project an image of an illumination source onto a specimen under measurement with a demagnification of 50, or less.

Methods and systems for compact, small spot size soft x-ray scatterometry

Methods and systems for performing spectroscopic measurements of semiconductor structures including ultraviolet, visible, and infrared wavelengths greater than two micrometers are presented herein. A spectroscopic measurement system includes a combined illumination source including a first illumination source that generates ultraviolet, visible, and near infrared wavelengths (wavelengths less than two micrometers) and a second illumination source that generates mid infrared and long infrared wavelengths (wavelengths of two micrometers and greater). Furthermore, the spectroscopic measurement system includes one or more measurement channels spanning the range of illumination wavelengths employed to perform measurements of semiconductor structures. In some embodiments, the one or more measurement channels simultaneously measure the sample throughout the wavelength range. In some other embodiments, the one or more measurement channels sequentially measure the sample throughout the wavelength range.

Methods and systems for measurement of thick films and high aspect ratio structures

Methods and systems are presented to reduce the illumination spot size projected onto a measurement target and associated spillover onto area surrounding a measurement target. In one aspect, a spatial light modulator (SLM) is located in the illumination path between the illumination light source and the measurement sample. The SLM is configured to modulate amplitude, phase, or both, across the path of the illumination light to reduce wavefront errors. In some embodiments, the desired state of the SLM is based on wavefront measurements performed in an optical path of the metrology system. In another aspect, an illumination aperture having an image plane tilted at an oblique angle with respect to a beam of illumination light is employed to overcome defocusing effects in metrology systems that employ oblique illumination of the measurement sample. In some embodiments, the illumination aperture, objective lens, and specimen are aligned to satisfy the Scheimpflug condition.

Optical metrology with small illumination spot size

Methods and systems for performing simultaneous spectroscopic measurements of semiconductor structures over a broad range of angles of incidence (AOI), azimuth angles, or both, are presented herein. Spectra including two or more sub-ranges of angles of incidence, azimuth angles, or both, are simultaneously measured over different sensor areas at high throughput. Collected light is linearly dispersed across different photosensitive areas of one or more detectors according to wavelength for each subrange of AOIs, azimuth angles, or both. Each different photosensitive area is arranged on the one or more detectors to perform a separate spectroscopic measurement for each different range of AOIs, azimuth angles, or both. In this manner, a broad range of AOIs, azimuth angles, or both, are detected with high signal to noise ratio, simultaneously. This approach enables high throughput measurements of high aspect ratio structures with high throughput, precision, and accuracy.

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Fliederweg, Germany

Kerstin Purrucker