Kla Tencor Corporation

Kla-tencor Technologies Corporation

Kla Corporation

Sathish Veeraraghavan

Jaydeep K Sinha

Pradeep Vukkadala

Haiguang Chen

Michael D Kirk

Amir Azordegan

Sergey Kamensky

Craig MacNaughton

Chin-Chou Huang

Rabi Fettig

Enrique Chavez

Soham Dey

Systems and methods for prediction and measurement of overlay errors are disclosed. Process-induced overlay errors may be predicted or measured utilizing film force based computational mechanics models. More specifically, information with respect to the distribution of film force is provided to a finite element (FE) model to provide more accurate point-by-point predictions in cases where complex stress patterns are present. Enhanced prediction and measurement of wafer geometry induced overlay errors are also disclosed.

Process-induced distortion prediction and feedforward and feedback correction of overlay errors

Systems and methods for providing improved measurements and predictions of geometry induced overlay errors are disclosed. Information regarding variations of overlay errors is obtained and analyzed to improve semiconductor processes as well as lithography patterning. In some embodiments, a cascading analysis process is utilized to breakdown the wafer geometry induced overlay into various components. The breakdown analysis may also be utilized to determine effectiveness factors for the various components, which in turn may improve the prediction accuracy of the impact of wafer geometry on wafer overlay. Furthermore, the measurements and/or predictions of the wafer geometry induced overlay errors may be utilized to provide overlay monitoring and correction solutions.

Breakdown analysis of geometry induced overlay and utilization of breakdown analysis for improved overlay control

Systems and methods for improving results of wafer higher order shape (HOS) characterization and wafer classification are disclosed. The systems and methods in accordance with the present disclosure are based on localized shapes. A wafer map is partitioned into a plurality of measurement sites to improve the completeness of wafer shape representation. Various site based HOS metric values may be calculated for wafer characterization and/or classification purposes, and may also be utilized as control input for a downstream application. In addition, polar grid partitioning schemes are provided. Such polar grid partitioning schemes may be utilized to partition a wafer surface into measurement sites having uniform site areas while providing good wafer edge region coverage.

Systems, methods and metrics for wafer high order shape characterization and wafer classification using wafer dimensional geometry tool

The present invention may include acquiring a wafer shape value at a plurality of points of a wafer surface at a first and second process level, generating a wafer shape change value at each of the points, generating a set of slope of shape change values at each of the points, calculating a set of process tool correctables utilizing the generated set of slope of shape change values, generating a set of slope shape change residuals (SSCRs) by calculating a slope of shape change residual value at each of the points utilizing the set of process tool correctables, defining a plurality of metric analysis regions distributed across the surface, and then generating one or more residual slope shape change metrics for each metric analysis region based on one or more SSCRs within each metric analysis region.

Overlay and semiconductor process control using a wafer geometry metric

Systems and methods for prediction of in-plane distortions (IPD) due to wafer shape in semiconductor wafer chucking process is disclosed. A series of Zernike basis wafer shapes process to emulate the non-linear finite element (FE) contact mechanics model based IPD prediction is utilized in accordance with one embodiment of the present disclosure. The emulated FE model based prediction process is substantially more efficient and provides accuracy comparable to the FE model based IPD prediction that utilizes full-scale 3-D wafer and chuck geometry information and requires computation intensive simulations. Furthermore, an enhanced HOS IPD/OPD prediction process based on a series of Zernike basis wafer shape images is also disclosed.

System and method to emulate finite element model based prediction of in-plane distortions due to semiconductor wafer chucking

Systems and methods for providing improved wafer geometry measurements are disclosed. A wafer geometry measurement system may utilize techniques that enable the wafer geometry measurement system to identify and reduce wafer surface errors caused by structures such as patterns on the wafers being measured. The wafer geometry measurement system may also utilize techniques that enable the wafer geometry measurement system to accurately reconstruct patterned wafer surfaces.

Systems and methods for effective pattern wafer surface measurement and analysis using interferometry tool

Systems and methods for predicting and controlling pattern quality data (e.g., critical dimension and/or pattern defectivity) in patterned wafers using patterned wafer geometry (PWG) measurements are disclosed. Correlations between PWG measurements and pattern quality data measurements may be established, and the established correlations may be utilized to provide pattern quality data predictions for a given wafer based on geometry measurements obtained for the give wafer. The predictions produced may be provided to a lithography tool, which may utilize the predictions to correct focus and/or title errors that may occur during the lithography process.

Predicting and controlling critical dimension issues and pattern defectivity in wafers using interferometry

Systems and methods for providing improved scanner corrections are disclosed. Scanner corrections provided in accordance with the present disclosure may be referred to as wafer geometry aware scanner corrections. More specifically, wafer geometry and/or wafer shape signature information are utilized to improve scanner corrections. By removing the wafer geometry as one of the error sources that may affect the overlay accuracy, better scanner corrections can be obtained because one less contributing factor needs to be modeled.

Using wafer geometry to improve scanner correction effectiveness for overlay control

Systems and methods for prediction of in-plane distortions (IPD) due to wafer shape in semiconductor wafer chucking process is disclosed. A process to emulate the non-linear finite element (FE) contact mechanics model based IPD prediction is utilized in accordance with one embodiment of the present disclosure. The emulated FE model based prediction process is substantially more efficient and provides accuracy comparable to the FE model based IPD prediction that utilizes full-scale 3-D wafer and chuck geometry information and requires computation intensive simulations. Furthermore, an enhanced HOS IPD/OPD prediction process based on a series of Zernike basis wafer shape images is also disclosed.

A method and system for modeling and analyzing wafer nanotopography data utilizes a nonlinear contact finite element model. Inputs to the model include lithography chuck parameters and site-based geometry data. Outputs from the model include in-plane distortions and out-of-plane distortions, from which defocus and overlay can be derived.

Site based quantification of substrate topography and its relation to lithography defocus and overlay

A system for evaluating the metrological characteristics of a surface of a substrate, the system including an optical substrate measurement system, a data analyzing system for analyzing data in an evaluation area on the substrate, applying feature-specific filters to characterize the surface of the substrate, and produce surface-specific metrics for characterizing and quantifying a feature of interest, the surface-specific metrics including a range metric for quantifying maximum and minimum deviations in the evaluation area, a deviation metric for quantifying a point deviation having a largest magnitude in a set of point deviations, where the point deviations are an amount of deviation from a reference plane fit to the evaluation area, and a root mean square metric calculated from power spectral density.

Growing community of inventors

Santa Clara, CA, United States of America

Sathish Veeraraghavan