Kla Tencor Corporation

Kla Corporation

Sharon Aharon

Vladimir Levinski

Yoel Feler

Roel Gronheid

Evgeni Gurevich

Amnon Manassen

Michael E Adel

Mark Ghinovker

Yuri Paskover

Anna Golotsvan

Mark Davis Smith

Daria Negri

Yuval Lubashevsky

Dana Klein

Eitan Hajaj

Myungjun Lee

Tal Itzkovich

Mark D Smith

Metrology methods and targets are provided for reducing or eliminating a difference between a device pattern position and a target pattern position while maintaining target printability, process compatibility and optical contrast—in both imaging and scatterometry metrology. Pattern placement discrepancies may be reduced by using sub-resolved assist features in the mask design which have a same periodicity (fine pitch) as the periodic structure and/or by calibrating the measurement results using PPE (pattern placement error) correction factors derived by applying learning procedures to specific calibration terms, in measurements and/or simulations. Metrology targets are disclosed with multiple periodic structures at the same layer (in addition to regular target structures), e.g., in one or two layers, which are used to calibrate and remove PPE, especially when related to asymmetric effects such as scanner aberrations, off-axis illumination and other error sources.

Reduction or elimination of pattern placement error in metrology measurements

Metrology methods and targets are provided for reducing or eliminating a difference between a device pattern position and a target pattern position while maintaining target printability, process compatibility and optical contrast&#x2014;in both imaging and scatterometry metrology. Pattern placement discrepancies may be reduced by using sub-resolved assist features in the mask design which have a same periodicity (fine pitch) as the periodic structure and/or by calibrating the measurement results using PPE (pattern placement error) correction factors derived by applying learning procedures to specific calibration terms, in measurements and/or simulations. Metrology targets are disclosed with multiple periodic structures at the same layer (in addition to regular target structures), e.g., in one or two layers, which are used to calibrate and remove PPE, especially when related to asymmetric effects such as scanner aberrations, off-axis illumination and other error sources.

A parameter-stable misregistration measurement amelioration system and method including providing a wafer, including a plurality of multilayered semiconductor devices formed thereon, selected from a batch wafers intended to be identical, using a misregistration metrology tool to measure misregistration at multiple sites between at least a first layer and a second layer of the wafer, using a plurality of sets of measurement parameters, thereby generating measured misregistration data for each of the sets of measurement parameters, identifying and removing a parameter-dependent portion and a mean error portion from the measured misregistration data for the wafer for each of the sets of measurement parameters, thereby generating ameliorated parameter-stable ameliorated misregistration data for the wafer.

Parameter-stable misregistration measurement amelioration in semiconductor devices

Methods are provided for designing metrology targets and estimating the uncertainty error of metrology metric values with respect to stochastic noise such as line properties (e.g., line edge roughness, LER). Minimal required dimensions of target elements may be derived from analysis of the line properties and uncertainty error of metrology measurements, by either CDSEM (critical dimension scanning electron microscopy) or optical systems, with corresponding targets. The importance of this analysis is emphasized in view of the finding that stochastic noise may have increased importance with when using more localized models such as CPE (correctables per exposure). The uncertainty error estimation may be used for target design, enhancement of overlay estimation and evaluation of measurement reliability in multiple contexts.

Determining the impacts of stochastic behavior on overlay metrology data

Metrology targets and target design methods are provided, in which target elements are defined by replacing elements from a periodic pattern having a pitch p, by assist elements having at least one geometric difference from the replaced elements, to form a composite periodic structure that maintains the pitch p as a single pitch. Constructing targets within the bounds of compatibility with advanced multiple patterning techniques improves the fidelity of the targets and fill factor modulation enables adjustment of the targets to produce sufficient metrology sensitivity for extracting the overlay while achieving process compatibility of the targets.

Process compatibility improvement by fill factor modulation

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Hanaton, Israel

Sharon Aharon