Asml Netherlands B.v.

Andreas Fuchs

Maurits Van Der Schaar

Arie Jeffrey Den Boef

Kaustuve Bhattacharyya

Hendrik Jan Hidde Smilde

Richard Johannes Franciscus Van Haren

Martin Jacobus Johan Jak

Henricus Wilhelmus Maria Van Buel

Michael Kubis

Xing Lan Liu

Omer Abubaker Omer Adam

Christophe David Fouquet

Johannes Marcus Maria Beltman

Martyn John Coogans

Marcus Adrianus Van De Kerkhof

Scott Anderson Middlebrooks

Panagiotis Pieter Bintevinos

Everhardus Cornelis Mos

Antoine Gaston Marie Kiers

Peter Hanzen Wardenier

Leonardus Henricus Marie Verstappen

Hilko Dirk Bos

Amandev Singh

Stephen Peter Morgan

Maxime D'Alfonso

MIchael Kubis

A diffraction measurement target that has at least a first sub-target and at least a second sub-target, and wherein (1) the first and second sub-targets each include a pair of periodic structures and the first sub-target has a different design than the second sub-target, the different design including the first sub-target periodic structures having a different pitch, feature width, space width, and/or segmentation than the second sub-target periodic structure or (2) the first and second sub-targets respectively include a first and second periodic structure in a first layer, and a third periodic structure is located at least partly underneath the first periodic structure in a second layer under the first layer and there being no periodic structure underneath the second periodic structure in the second layer, and a fourth periodic structure is located at least partly underneath the second periodic structure in a third layer under the second layer.

Metrology method, target and substrate

A scatterometer is used in a dark-field imaging mode to measure asymmetry-related parameters such as overlay. Measurements of small grating targets are made using identical optical paths, with the target in two orientations to obtain separate measurements of +1 and &#x2212;1 diffraction orders. In this way, intensity scaling differences (tool asymmetry) are avoided. However, additive intensity defects due to stray radiation (ghosts) in the optical system cannot be avoided. Additive intensity issues strongly depend on the ratio between 0th and 1st order diffraction and are therefore strongly substrate (process) dependent. Calibration measurements are made on a few representative target gratings having biases. The calibration measurements are made, using not only different substrate rotations but also complementary apertures. Corrections are calculated and applied to correct asymmetry, to reduce error caused by stray radiation.

Method of measuring asymmetry, inspection apparatus, lithographic system and device manufacturing method

The present invention makes the use of measurement of a diffraction spectrum in or near an image plane in order to determine a property of an exposed substrate. In particular, the positive and negative first diffraction orders are separated or diverged, detected and their intensity measured. The intensity of each of the first diffraction orders from the diffraction spectrum are compared to determine overlay (or other properties) of exposed layers on the substrate.

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

A method for determining overlay error includes measuring asymmetry of radiation reflected from each of a plurality of targets on a substrate. The plurality of targets include a predetermined overlay offset. The method also includes comparing the measured asymmetry of the radiation reflected from each of the plurality of targets to the corresponding predetermined overlay offset of the respective target. Additionally, the method includes determining the overlay error of a point on the substrate as a function of measured asymmetry reflected from the point. The function is determined by fitting a polynomial or a Fourier series to a comparison of the measured asymmetry of the radiation reflected from each of the plurality of targets to the corresponding predetermined overlay offset of the respective target. The function limits an effect of linearity error.

Inspection methods, inspection apparatuses, and lithographic apparatuses

An inspection apparatus measures a property of a substrate including a periodic structure. An illumination system provides a beam of radiation with an illumination profile including a plurality of illuminated portions. A radiation projector projects the beam of radiation onto the substrate. A detector detects radiation scattered from the periodic structure and separately detects first order diffracted radiation and at least one higher order of diffracted radiation of each of the illuminated portions. A processor determines the property of the substrate from the detected radiation. The plurality of illuminated portions are arranged such that first order diffracted radiation arising from one or more of the illuminated portions are not overlapped by zeroth order or first order diffracted radiation arising from any other of the illuminated portions. Furthermore, the plurality of illuminated portions are arranged such that first order diffracted radiation arising from the one or more of the illuminated portions are overlapped by at least one of the higher orders of diffracted radiation arising from any other of the illuminated portions.

Inspection apparatus and method for measuring a property of a substrate

A method of determining an overlay error. Measuring an overlay target having process-induced asymmetry. Constructing a model of the target. Modifying the model, e.g., by moving one of the structures to compensate for the asymmetry. Calculating an asymmetry-induced overlay error using the modified model. Determining an overlay error in a production target by subtracting the asymmetry-induced overlay error from a measured overlay error. In one example, the model is modified by varying asymmetry p, pand the calculating an asymmetry-induced overlay error is repeated for a plurality of scatterometer measurement recipes and the step of determining an overlay error in a production target uses the calculated asymmetry-induced overlay errors to select an optimum scatterometer measurement recipe used to measure the production target.

Method and apparatus for determining an overlay error

The present invention makes the use of measurement of a diffraction spectrum in or near an image plane in order to determine a property of an exposed substrate. In particular, the positive and negative first diffraction orders are separated or diverged, detected and their intensity measured to determine overlay (or other properties) of exposed layers on the substrate.

Apparatus and method of measuring a property of a substrate

A method and associated apparatus determine an overlay error on a substrate. A beam is projected onto three or more targets. Each target includes first and second overlapping patterns with predetermined overlay offsets on the substrate. The asymmetry of the radiation reflected from each target on the substrate is measured. The overlay error not resultant from the predetermined overlay offsets is determined. The function that enables calculation of overlay from asymmetry for other points on the wafer is determined by limiting the effect of linearity error when determining the overlay error from the function.

Inspection method and apparatus, and corresponding lithographic apparatus

A scatterometer configured to measure a property of a substrate, includes a radiation source configured to provide a radiation beam; and a detector configured to detect a spectrum of the radiation beam reflected from a target () on the surface of the substrate (W) and to produce a measurement signal representative of the spectrum. The apparatus includes a beam shaper () interposed in the radiation path between the radiation source and the detector, the beam shaper being configured to adjust the cross section of the beam dependent on the shape and/or size of the target.

Inspection apparatus for lithography

An apparatus measures properties, such as overlay error, of a substrate divided into a plurality of fields. The apparatus includes a radiation source configured to direct radiation onto a first target of each field of the substrate. Each first target (T4G) has at least a first grating and a second grating having respective predetermined offsets, the predetermined offset (+d) of the first grating being in a direction opposite the predetermined offset (&#x2212;d) of the second grating. A detector is configured to detect the radiation reflected from each first target and to obtain an asymmetry value for each first target from the detected radiation. Further, a module is configured to determine an overlay value for each first target based on at least the obtained asymmetry value and the predetermined offsets and determine a polynomial fit across a plurality of first targets of a corresponding plurality of fields of the substrate for a relationship between the obtained asymmetry value and determined overlay value of each first target.

Growing community of inventors

Meerbusch, Germany

Andreas Fuchs