An apparatus and method to determine a property of a substrate by measuring, in the pupil plane of a high numerical aperture lens, an angle-resolved spectrum as a result of radiation being reflected off the substrate. The property may be angle and wavelength dependent and may include the intensity of TM- and TE-polarized radiation and their relative phase difference.

Method and apparatus for angular-resolved spectroscopic lithography characterization

A method for determining overlay between a first grating (110) and a second grating (120) on a substrate (100), the second grating (120) on top of the first grating(110), the second grating (120) having substantially identical pitch (P1) as the first grating (110), the second and first gratings forming a composite grating (110,120), the method including providing a first illumination beam (IB) for illuminating the composite grating (110,120) under an angle of incidence (β) along a first horizontal direction (D1) along the surface of the substrate, and measuring a first intensity (i+) of a first order diffracted beam (B+) from the composite grating (110,120); providing a second illumination beam for illuminating the composite grating (11θ!i2O) under the angle of incidence (-β) along a second horizontal direction (D2) along the surface of the substrate, wherein the second horizontal direction (D2) is opposite to the first horizontal direction (DI)1 and measuring a second intensity (i-) of a minus first order diffracted beam (B-) from the composite grating (110,120).

Diffraction Based Overlay Metrology Tool and Method

In a method of determining the focus of a lithographic apparatus used in a lithographic process on a substrate, the lithographic process is used to form a structure on the substrate, the structure having at least one feature which has an asymmetry in the printed profile which varies as a function of the focus of the lithographic apparatus on the substrate. A first image of the periodic structure is formed and detected while illuminating the structure with a first beam of radiation. The first image is formed using a first part of non-zero order diffracted radiation. A second image of the periodic structure is formed and detected while illuminating the structure with a second beam of radiation. The second image is formed using a second part of the non-zero order diffracted radiation which is symmetrically opposite to the first part in a diffraction spectrum. The ratio of the intensities of the measured first and second portions of the spectra is determined and used to determine the asymmetry in the profile of the periodic structure and/or to provide an indication of the focus on the substrate. In the same instrument, an intensity variation across the detected portion is determined as a measure of process-induced variation across the structure. A region of the structure with unwanted process variation can be identified and excluded from a measurement of the structure.

Methods and Scatterometers, Lithographic Systems, and Lithographic Processing Cells

The simultaneous measurement of four separately polarized beams upon diffraction from a substrate is used to determine properties of the substrate. Circularly or elliptically polarized light sources are passed via up to three polarizing elements. This polarizes the light sources by 0, 45, 90 and 135°. The plurality of polarizing beamsplitters replaces the use of a phase modulator, but enables the measurement of the intensity of all four beams and thus the measurement of the phase modulation and amplitude of the combined beams to give the features of the substrate.

Inspection method and apparatus, lithographic apparatus, lithographic processing cell and device manufacturing method

A method including determining a type of structural asymmetry of the target from measured values of the target, and performing a simulation of optical measurement of the target to determine a value of an asymmetry parameter associated with the asymmetry type. A method including performing a simulation of optical measurement of a target to determine a value of an asymmetry parameter associated with a type of structural asymmetry of the target determined from measured values of the target, and analyzing a sensitivity of the asymmetry parameter to change in a target formation parameter associated with the target. A method including determining a structural asymmetry parameter of a target using a measured parameter of radiation diffracted by the target, and determining a property of a measurement beam of the target based on the structural asymmetry parameter that is least sensitive to change in a target formation parameter associated with the target.

Metrology method, computer product and system

According to the present invention, an apparatus and method are disclosed for determining the properties of a substrate by measuring the angle-resolved spectrum as a result of the radiation being reflected off the substrate in the pupil plane of the high numerical aperture lens. The properties may be dependent on angle and wavelength and may include the intensity of TM- and TE-polarized light and their associated phase differences.

헨리쿠스 페트루스 마리아 펠레만스

Papers

Method and apparatus for angular-resolved spectroscopic lithography characterization