Kla Tencor Corporation

Kla Corporation

Inna Tarshish-Shapir

Mark Ghinovker

Vladimir Levinski

Michael E Adel

Roie Volkovich

Yoel Feler

Guy Ben Dov

Diana Shaphirov

Chris Steely

Enna Leshinsky-Altshuller

Amnon Manassen

Nuriel Amir

Alexander Svizher

Boris Efraty

Anat Marchelli

Sigalit Robinzon

Shiming Wei

Berta Dinu

Jeremy (Shi-Ming) Wei

Metrology target design methods and verification targets are provided. Methods comprise using OCD data related to designed metrology target(s) as an estimation of a discrepancy between a target model and a corresponding actual target on a wafer, and adjusting a metrology target design model to compensate for the estimated discrepancy. The dedicated verification targets may comprise overlay target features and be size optimized to be measureable by an OCD sensor, to enable compensation for inaccuracies resulting from production process variation. Methods also comprise modifications to workflows between manufacturers and metrology vendors which provide enable higher fidelity metrology target design models and ultimately higher accuracy of metrology measurements.

Verification metrology targets and their design

A metrology system may include a controller to receive a first metrology dataset associated with a first set of metrology target features on a sample including first features from a first exposure field on a first sample layer and second features from a second exposure field on a second sample layer, where the second exposure field partially overlaps the first exposure field. The controller may further receive a second metrology dataset associated with a second set of metrology target features including third features from a third exposure field on the second layer that overlaps the first exposure field and fourth features formed from a fourth exposure field on the first layer of the sample that overlaps the second exposure field. The controller may further determine fabrication errors based on the first and second metrology datasets and generate correctables to adjust a lithography tool based on the fabrication errors.

Field-to-field corrections using overlay targets

Metrology targets, design methods and measurement methods thereof are provided with periodic structure(s) which are oblique with respect to orthogonal production axes X and Y of the lithography tool&#x2014;enabling more accurate overlay measurements of devices having diagonal (oblique, tilted) elements such as DRAM devices. One or more oblique periodic structure(s) may be used to provide one- or two-dimensional signals, with respect to one or more layers, possibly providing overlay measurements for multiple steps applied to one layer. The oblique periodic structure(s) may be used to modify current metrology target designs (e.g., imaging targets and/or scatterometry targets) or to design new targets, and measurement algorithms may be adjusted respectively to derive signals from the oblique periodic structure(s) and/or to provide pre-processed images thereof. The disclosed targets are process compatible and reflect more accurately the device overlays with respect to various process steps.

Metrology targets and methods with oblique periodic structures

A metrology system may include a controller coupled to a metrology tool. The controller may receive a metrology target design including at least a first feature formed by exposing a first exposure field on a sample with a lithography tool, and at least a second feature formed by exposing a second exposure field on the sample with the lithography tool, where the second exposure field overlaps the first exposure field at a location of a metrology target on the sample. The controller may further receive metrology data associated with the metrology target fabricated according to the metrology target design, determine one or more fabrication errors during fabrication of the metrology target based on the metrology data, and generate correctables to adjust one or more fabrication parameters of the lithography tool in one or more subsequent lithography steps based on the one or more fabrication errors.

Metrology target design methods and verification targets are provided. Methods include using OCD data related to designed metrology target(s) as an estimation of a discrepancy between a target model and a corresponding actual target on a wafer, and adjusting a metrology target design model to compensate for the estimated discrepancy. The dedicated verification targets may include overlay target features and be size optimized to be measurable by an OCD sensor, to enable compensation for inaccuracies resulting from production process variation. Methods also include modifications to workflows between manufacturers and metrology vendors which provide enabled higher fidelity metrology target design models and ultimately higher accuracy of metrology measurements.

Verification metrology target and their design

Methods and systems are provided, which identify specified metrology target abnormalities using selected metrics and classify the identified target abnormalities geometrically to link them to corresponding sources of error. Identification may be carried out by deriving target signals such as kernels from specified regions of interest (ROIs) from corresponding targets on a wafer, calculating the metrics from the target signals using respective functions and analyzing the metrics to characterize the targets.

Method, system, and user interface for metrology target characterization

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Haifa, Israel

Inna Tarshish-Shapir