Kla-Tencor Technologies Corporation

Kla Tencor Corporation

Steve R Lange

Tao-Yi Fu

Shiow-Hwei Hwang

Paul Frank Marella

Nat Ceglio

Lisheng Gao

David R Shafer

Xuguang Jiang

Sylvain Muckenhirn

Ping Gu

Charles E Wayman

Methods and systems for monitoring a non-defect related characteristic of a patterned wafer are provided. One computer-implemented method includes generating output responsive to light from a patterned wafer using an inspection system. The method also includes determining differences between a value of a non-defect related characteristic of the patterned wafer and a known value of the non-defect related characteristic based on differences between one or more attributes of the output and one or more attributes of other output of the inspection system for a different patterned wafer having the known value of the non-defect related characteristic.

Methods and systems for monitoring a non-defect related characteristic of a patterned wafer

Methods and systems for inspection of a specimen using different parameters are provided. One computer-implemented method includes determining optimal parameters for inspection based on selected defects. This method also includes setting parameters of an inspection system at the optimal parameters prior to inspection. Another method for inspecting a specimen includes illuminating the specimen with light having a wavelength below about 350 nm and with light having a wavelength above about 350 nm. The method also includes processing signals representative of light collected from the specimen to detect defects or process variations on the specimen. One system configured to inspect a specimen includes a first optical subsystem coupled to a broadband light source and a second optical subsystem coupled to a laser. The system also includes a third optical subsystem configured to couple light from the first and second optical subsystems to an objective, which focuses the light onto the specimen.

Methods and systems for inspection of a specimen using different inspection parameters

A technique for focusing and maintaining the focus of an inspection or review system upon a specific layer of a multi-layered specimen is described. In one embodiment, a confocal autofocus system can be used to focus an optical inspection or review system upon the top layer of a semiconductor wafer thin-film stack. The confocal autofocus system utilizes a tilted mask having a linear array of apertures or a continuous slit that is aligned so that a respective linear array of focal points or a focal slit is parallel with a scanning axis of the inspection system. Appropriate processing of the profile depth information yields knowledge of the depth of various layers in the specimen and allows for selection of the layer or location of interest upon which to focus the inspection or review system.

Slit confocal autofocus system

An optical system comprising three lens sections, a catadioptric objective lens section, a reimaging lens section and a zoom lens section, which are all aligned along the optical path of the optical system. The reimaging lens section re-images the system pupil such that the re-imaged pupil is accessible separately from any of the lens sections. The reimaging lens section includes an intermediate focus lens group, which is used to create an intermediate focus, a recollimating lens group, which is used to recollimate the light traveling from the intermediate focus lens group, refocusing group to generate the re-image of the pupil. The optical system may also include a beamsplitter, which creates a separated illumination pupil and collection pupil. The illumination pupil and the collection pupil may then be manipulated with an illumination aperture and a collection aperture, respectively, so that the optical system may operate in various test modes such as brightfield, ring darkfield, full-sky illumination, and laser darkfield with Fourier filtering capability. Another aspect of the invention pertains to a method for using the broad spectral region catadioptric optical system. The method includes the operations of directing radiation from a radiation source so that the radiation passes through the illumination pupil and the collection pupil of the optical system. The method also includes operations for configuring the illumination pupil and the collection pupil so that the optical system may operate in brightfield, ring darkfield, full-sky or laser darkfield illumination mode, with Fourier filtering capability.

Lens for microscopic inspection

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Alamo, VA, United States of America

Steve R Lange