Kla Tencor Corporation

Kla Corporation

Ofer Zaharan

Amnon Manassen

Daniel Kandel

Ohad Bachar

Barak Bringoltz

Nadav Carmel

Vladimir Levinski

Yoel Feler

Noam Sapiens

Daria Negri

Nuriel Amir

Joel L Seligson

Alexander Svizher

Tal Marciano

Tzahi Grunzweig

Evgeni Gurevich

Andy Hill

Boris Efraty

Ido Adam

Tal Yaziv

Lilach Saltoun

Noga Sella

Tom Leviant

Moshe Baruch

Oded Kaminsky

Amir Handelman

Zeng Zhao

Moshe Cooper

Roee Sulimarski

Eltsafon Ashwal

Victoria Naipak

Ze'ev Lindenfeld

Methods are provided for deriving a partially continuous dependency of metrology metric(s) on recipe parameter(s), analyzing the derived dependency, determining a metrology recipe according to the analysis, and conducting metrology measurement(s) according to the determined recipe. The dependency may be analyzed in form of a landscape such as a sensitivity landscape in which regions of low sensitivity and/or points or contours of low or zero inaccuracy are detected, analytically, numerically or experimentally, and used to configure parameters of measurement, hardware and targets to achieve high measurement accuracy. Process variation is analyzed in terms of its effects on the sensitivity landscape, and these effects are used to characterize the process variation further, to optimize the measurements and make the metrology both more robust to inaccuracy sources and more flexible with respect to different targets on the wafer and available measurement conditions.

Method of analyzing and utilizing landscapes to reduce or eliminate inaccuracy in overlay optical metrology

Methods and metrology modules and tools are provided, which minimize an estimated overlay variation measure at misalignment vector values obtained from a derived functional form of an overlay linear response to non-periodic effects. Provided methods further quantifying target noise due to the non-periodic effects using multiple repeated overlay measurements of the target cells, calculating an ensemble of overlay measurements between the cells over the multiple measurement repeats and expressing the target noise as a statistical derivative of the calculated overlay measurements. Sub-ensembles may be selected to further characterize the target noise. Various outputs include optimized scanning patterns, target noise metrics and recipe and target optimization.

Decreasing inaccuracy due to non-periodic effects on scatterometric signals

The present invention may include measuring a first phase distribution across a pupil plane of a portion of illumination reflected from a first overlay target of a semiconductor wafer, wherein the first overlay target is fabricated to have a first intentional overlay, measuring a second phase distribution across the pupil plane of a portion of illumination reflected from a second overlay target, wherein the second overlay target is fabricated to have a second intentional overlay in a direction opposite to and having the same magnitude as the first intentional overlay, determining a first phase tilt associated with a sum of the first and second phase distributions, determining a second phase tilt associated with a difference between the first and second phase distributions, calibrating a set of phase tilt data, and determining a test overlay value associated with the first and second overlay target.

Overlay metrology by pupil phase analysis

Growing community of inventors

Jerusalem, Israel

Ofer Zaharan