Kla Tencor Corporation

Kla Corporation

Dror Alumot

Liran Yerushalmi

Daniel Kandel

Eran Amit

Amit Shaked

Amnon Manassen

Michael E Adel

Ady Levy

Yoel Feler

Barak Bringoltz

John Charles Robinson

Pradeep Subrahmanyan

DongSub Choi

Evgeni Gurevich

William Pierson

Dongsub Choi

Yuval Lamhot

Tal Yaziv

Lilach Saltoun

Ido Adam

Noga Sella

Hoyoung Heo

Tom Leviant

Eltsafon Ashwal

Eltsafon Ashwal-Island

Yaron De Leeuw

Yaron Deleeuw

John Robinson

Michael A Adel

Methods, metrology modules and target designs are provided, which improve the accuracy of metrology measurements. Methods provide flexible handling of multiple measurement recipes and setups and enable relating them to landscape features that indicate their relation to resonance regions and to flat regions. Clustering of recipes, self-consistency tests, common processing of aggregated measurements, noise reduction, cluster analysis, detailed analysis of the landscape and targets with skewed cells are employed separately or in combination to provide cumulative improvements of measurement accuracy.

Accuracy improvements in optical metrology

An overlay metrology system includes one or more processors coupled to an illumination source to direct illumination to a sample and a detector to capture diffracted orders of radiation from the sample. The system may generate overlay sensitivity calibration parameters based on differential measurements of a calibration target including two overlay target cells on the sample, where first-layer target elements and second-layer target elements of the overlay target cells are distributed with a common pitch along a measurement direction and are misregistered with a selected offset value in opposite directions. The system may further determine overlay measurements based on differential measurements of additional overlay target cells with two wavelengths, where first-layer target elements and second-layer target elements of the additional overlay target cells are distributed with the common pitch and are formed to overlap symmetrically. The system may further adjust the overlay measurements with the overlay sensitivity calibration parameters.

Device metrology targets and methods

Metrology methods and targets are provided, that expand metrological procedures beyond current technologies into multi-layered targets, quasi-periodic targets and device-like targets, without having to introduce offsets along the critical direction of the device design. Several models are disclosed for deriving metrology data such as overlays from multi-layered target and corresponding configurations of targets are provided to enable such measurements. Quasi-periodic targets which are based on device patterns are shown to improve the similarity between target and device designs, and the filling of the surroundings of targets and target elements with patterns which are based on device patterns improve process compatibility. Offsets are introduced only in non-critical direction and/or sensitivity is calibrated to enable, together with the solutions for multi-layer measurements and quasi-periodic target measurements, direct device optical metrology measurements.

A process control system may include a controller configured to receive after-development inspection (ADI) data after a lithography step for the current layer from an ADI tool, receive after etch inspection (AEI) overlay data after an exposure step of the current layer from an AEI tool, train a non-zero offset predictor with ADI data and AEI overlay data to predict a non-zero offset from input ADI data, generate values of the control parameters of the lithography tool using ADI data and non-zero offsets generated by the non-zero offset predictor, and provide the values of the control parameters to the lithography tool for fabricating the current layer on the at least one production sample.

Overlay control with non-zero offset prediction

Growing community of inventors

Rehovot, Israel

Dror Alumot