Patents by Inventor Zhengquan Tan
Zhengquan Tan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11796390Abstract: A spectroscopic metrology system includes a spectroscopic metrology tool and a controller. The controller generates a model of a multilayer grating including two or more layers, the model including geometric parameters indicative of a geometry of a test layer of the multilayer grating and dispersion parameters indicative of a dispersion of the test layer. The controller further receives a spectroscopic signal of a fabricated multilayer grating corresponding to the modeled multilayer grating from the spectroscopic metrology tool. The controller further determines values of the one or more parameters of the modeled multilayer grating providing a simulated spectroscopic signal corresponding to the measured spectroscopic signal within a selected tolerance. The controller further predicts a bandgap of the test layer of the fabricated multilayer grating based on the determined values of the one or more parameters of the test layer of the fabricated structure.Type: GrantFiled: July 1, 2022Date of Patent: October 24, 2023Assignee: KLA CorporationInventors: Tianhan Wang, Aaron Rosenberg, Dawei Hu, Alexander Kuznetsov, Manh Dang Nguyen, Stilian Pandev, John Lesoine, Qiang Zhao, Liequan Lee, Houssam Chouaib, Ming Di, Torsten R. Kaack, Andrei V. Shchegrov, Zhengquan Tan
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Patent number: 11573077Abstract: Methods and systems for measuring optical properties of transistor channel structures and linking the optical properties to the state of strain are presented herein. Optical scatterometry measurements of strain are performed on metrology targets that closely mimic partially manufactured, real device structures. In one aspect, optical scatterometry is employed to measure uniaxial strain in a semiconductor channel based on differences in measured spectra along and across the semiconductor channel. In a further aspect, the effect of strain on measured spectra is decorrelated from other contributors, such as the geometry and material properties of structures captured in the measurement. In another aspect, measurements are performed on a metrology target pair including a strained metrology target and a corresponding unstrained metrology target to resolve the geometry of the metrology target under measurement and to provide a reference for the estimation of the absolute value of strain.Type: GrantFiled: June 3, 2021Date of Patent: February 7, 2023Assignee: KLA CorporationInventors: Houssam Chouaib, Aaron Rosenberg, Kai-Hsiang Lin, Dawei Hu, Zhengquan Tan
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Patent number: 11555689Abstract: Methods and systems disclosed herein can measure thin film stacks, such as film on grating and bandgap on grating in semiconductors. For example, the thin film stack may be a 1D film stack, a 2D film on grating, or a 3D film on grating. One or more effective medium dispersion models are created for the film stack. Each effective medium dispersion model can substitute for one or more layers. A thickness of one or more layers can be determined using the effective medium dispersion based scatterometry model. In an instance, three effective medium dispersion based scatterometry models are developed and used to determine thickness of three layers in a film stack.Type: GrantFiled: April 15, 2020Date of Patent: January 17, 2023Assignee: KLA-Tencor CorporationInventors: Houssam Chouaib, Zhengquan Tan
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Publication number: 20220349752Abstract: A spectroscopic metrology system includes a spectroscopic metrology tool and a controller. The controller generates a model of a multilayer grating including two or more layers, the model including geometric parameters indicative of a geometry of a test layer of the multilayer grating and dispersion parameters indicative of a dispersion of the test layer. The controller further receives a spectroscopic signal of a fabricated multilayer grating corresponding to the modeled multilayer grating from the spectroscopic metrology tool. The controller further determines values of the one or more parameters of the modeled multilayer grating providing a simulated spectroscopic signal corresponding to the measured spectroscopic signal within a selected tolerance. The controller further predicts a bandgap of the test layer of the fabricated multilayer grating based on the determined values of the one or more parameters of the test layer of the fabricated structure.Type: ApplicationFiled: July 1, 2022Publication date: November 3, 2022Inventors: Tianhan Wang, Aaron Rosenberg, Dawei Hu, Alexander Kuznetsov, Manh Dang Nguyen, Stilian Pandev, John Lesoine, Qiang Zhao, Liequan Lee, Houssam Chouaib, Ming Di, Torsten R. Kaack, Andrei V. Shchegrov, Zhengquan Tan
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Patent number: 11378451Abstract: A spectroscopic metrology system includes a spectroscopic metrology tool and a controller. The controller generates a model of a multilayer grating including two or more layers, the model including geometric parameters indicative of a geometry of a test layer of the multilayer grating and dispersion parameters indicative of a dispersion of the test layer. The controller further receives a spectroscopic signal of a fabricated multilayer grating corresponding to the modeled multilayer grating from the spectroscopic metrology tool. The controller further determines values of the one or more parameters of the modeled multilayer grating providing a simulated spectroscopic signal corresponding to the measured spectroscopic signal within a selected tolerance. The controller further predicts a bandgap of the test layer of the fabricated multilayer grating based on the determined values of the one or more parameters of the test layer of the fabricated structure.Type: GrantFiled: August 8, 2017Date of Patent: July 5, 2022Assignee: KLA CorporationInventors: Tianhan Wang, Aaron Rosenberg, Dawei Hu, Alexander Kuznetsov, Manh Dang Nguyen, Stilian Pandev, John Lesoine, Qiang Zhao, Liequan Lee, Houssam Chouaib, Ming Di, Torsten R. Kaack, Andrei V. Shchegrov, Zhengquan Tan
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Publication number: 20210293532Abstract: Methods and systems for measuring optical properties of transistor channel structures and linking the optical properties to the state of strain are presented herein. Optical scatterometry measurements of strain are performed on metrology targets that closely mimic partially manufactured, real device structures. In one aspect, optical scatterometry is employed to measure uniaxial strain in a semiconductor channel based on differences in measured spectra along and across the semiconductor channel. In a further aspect, the effect of strain on measured spectra is decorrelated from other contributors, such as the geometry and material properties of structures captured in the measurement. In another aspect, measurements are performed on a metrology target pair including a strained metrology target and a corresponding unstrained metrology target to resolve the geometry of the metrology target under measurement and to provide a reference for the estimation of the absolute value of strain.Type: ApplicationFiled: June 3, 2021Publication date: September 23, 2021Inventors: Houssam Chouaib, Aaron Rosenberg, Kai-Hsiang Lin, Dawei Hu, Zhengquan Tan
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Patent number: 11060846Abstract: Methods and systems for measuring optical properties of transistor channel structures and linking the optical properties to the state of strain are presented herein. Optical scatterometry measurements of strain are performed on metrology targets that closely mimic partially manufactured, real device structures. In one aspect, optical scatterometry is employed to measure uniaxial strain in a semiconductor channel based on differences in measured spectra along and across the semiconductor channel. In a further aspect, the effect of strain on measured spectra is decorrelated from other contributors, such as the geometry and material properties of structures captured in the measurement. In another aspect, measurements are performed on a metrology target pair including a strained metrology target and a corresponding unstrained metrology target to resolve the geometry of the metrology target under measurement and to provide a reference for the estimation of the absolute value of strain.Type: GrantFiled: October 22, 2019Date of Patent: July 13, 2021Assignee: KLA CorporationInventors: Houssam Chouaib, Aaron Rosenberg, Kai-Hsiang Lin, Dawei Hu, Zhengquan Tan
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Publication number: 20200240768Abstract: Methods and systems disclosed herein can measure thin film stacks, such as film on grating and bandgap on grating in semiconductors. For example, the thin film stack may be a 1D film stack, a 2D film on grating, or a 3D film on grating. One or more effective medium dispersion models are created for the film stack. Each effective medium dispersion model can substitute for one or more layers. A thickness of one or more layers can be determined using the effective medium dispersion based scatterometry model. In an instance, three effective medium dispersion based scatterometry models are developed and used to determine thickness of three layers in a film stack.Type: ApplicationFiled: April 15, 2020Publication date: July 30, 2020Inventors: Houssam Chouaib, Zhengquan Tan
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Publication number: 20200200525Abstract: Methods and systems for measuring optical properties of transistor channel structures and linking the optical properties to the state of strain are presented herein. Optical scatterometry measurements of strain are performed on metrology targets that closely mimic partially manufactured, real device structures. In one aspect, optical scatterometry is employed to measure uniaxial strain in a semiconductor channel based on differences in measured spectra along and across the semiconductor channel. In a further aspect, the effect of strain on measured spectra is decorrelated from other contributors, such as the geometry and material properties of structures captured in the measurement. In another aspect, measurements are performed on a metrology target pair including a strained metrology target and a corresponding unstrained metrology target to resolve the geometry of the metrology target under measurement and to provide a reference for the estimation of the absolute value of strain.Type: ApplicationFiled: October 22, 2019Publication date: June 25, 2020Inventors: Houssam Chouaib, Aaron Rosenberg, Kai-Hsiang Lin, Dawei Hu, Zhengquan Tan
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Patent number: 10663286Abstract: Methods and systems disclosed herein can measure thin film stacks, such as film on grating and bandgap on grating in semiconductors. For example, the thin film stack may be a 1D film stack, a 2D film on grating, or a 3D film on grating. One or more effective medium dispersion models are created for the film stack. Each effective medium dispersion model can substitute for one or more layers. A thickness of one or more layers can be determined using the effective medium dispersion based scatterometry model. In an instance, three effective medium dispersion based scatterometry models are developed and used to determine thickness of three layers in a film stack.Type: GrantFiled: November 1, 2017Date of Patent: May 26, 2020Assignee: KLA-Tencor CorporationInventors: Houssam Chouaib, Zhengquan Tan
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Patent number: 10458912Abstract: Methods and systems for performing optical, model based measurements of a small sized semiconductor structure employing an anisotropic characterization of the optical dispersion properties of one or more materials comprising the structure under measurement are presented herein. This reduces correlations among geometric parameters and results in improved measurement sensitivity, improved measurement accuracy, and enhanced measurement contrast among multiple materials under measurement. In a further aspect, an element of a multidimensional tensor describing the dielectric permittivity of the materials comprising the structure is modelled differently from another element. In a further aspect, model based measurements are performed based on measurement data collected from two or more measurement subsystems combined with an anisotropic characterization of the optical dispersion of the materials under measurement.Type: GrantFiled: July 14, 2017Date of Patent: October 29, 2019Assignee: KLA-Tencor CorporationInventors: Houssam Chouaib, Qiang Zhao, Andrei V. Shchegrov, Zhengquan Tan
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Publication number: 20190063900Abstract: Methods and systems disclosed herein can measure thin film stacks, such as film on grating and bandgap on grating in semiconductors. For example, the thin film stack may be a 1D film stack, a 2D film on grating, or a 3D film on grating. One or more effective medium dispersion models are created for the film stack. Each effective medium dispersion model can substitute for one or more layers. A thickness of one or more layers can be determined using the effective medium dispersion based scatterometry model. In an instance, three effective medium dispersion based scatterometry models are developed and used to determine thickness of three layers in a film stack.Type: ApplicationFiled: November 1, 2017Publication date: February 28, 2019Inventors: Houssam Chouaib, Zhengquan Tan
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Publication number: 20190041266Abstract: A spectroscopic metrology system includes a spectroscopic metrology tool and a controller. The controller generates a model of a multilayer grating including two or more layers, the model including geometric parameters indicative of a geometry of a test layer of the multilayer grating and dispersion parameters indicative of a dispersion of the test layer. The controller further receives a spectroscopic signal of a fabricated multilayer grating corresponding to the modeled multilayer grating from the spectroscopic metrology tool. The controller further determines values of the one or more parameters of the modeled multilayer grating providing a simulated spectroscopic signal corresponding to the measured spectroscopic signal within a selected tolerance. The controller further predicts a bandgap of the test layer of the fabricated multilayer grating based on the determined values of the one or more parameters of the test layer of the fabricated structure.Type: ApplicationFiled: August 8, 2017Publication date: February 7, 2019Inventors: Tianhan Wang, Aaron Rosenberg, Dawei Hu, Alexander Kuznetsov, Manh Dang Nguyen, Stilian Pandev, John Lesoine, Qiang Zhao, Liequan Lee, Houssam Chouaib, Ming Di, Torsten R. Kaack, Andrei V. Shchegrov, Zhengquan Tan
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Patent number: 10013518Abstract: Structural parameters of a specimen are determined by fitting models of the response of the specimen to measurements collected by different measurement techniques in a combined analysis. Models of the response of the specimen to at least two different measurement technologies share at least one common geometric parameter. In some embodiments, a model building and analysis engine performs x-ray and optical analyses wherein at least one common parameter is coupled during the analysis. The fitting of the response models to measured data can be done sequentially, in parallel, or by a combination of sequential and parallel analyses. In a further aspect, the structure of the response models is altered based on the quality of the fit between the models and the corresponding measurement data. For example, a geometric model of the specimen is restructured based on the fit between the response models and corresponding measurement data.Type: GrantFiled: July 3, 2013Date of Patent: July 3, 2018Assignee: KLA-Tencor CorporationInventors: Michael S. Bakeman, Andrei V. Shchegrov, Qiang Zhao, Zhengquan Tan
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Publication number: 20180059019Abstract: Methods and systems for performing optical, model based measurements of a small sized semiconductor structure employing an anisotropic characterization of the optical dispersion properties of one or more materials comprising the structure under measurement are presented herein. This reduces correlations among geometric parameters and results in improved measurement sensitivity, improved measurement accuracy, and enhanced measurement contrast among multiple materials under measurement. In a further aspect, an element of a multidimensional tensor describing the dielectric permittivity of the materials comprising the structure is modelled differently from another element. In a further aspect, model based measurements are performed based on measurement data collected from two or more measurement subsystems combined with an anisotropic characterization of the optical dispersion of the materials under measurement.Type: ApplicationFiled: July 14, 2017Publication date: March 1, 2018Inventors: Houssam Chouaib, Qiang Zhao, Andrei V. Shchegrov, Zhengquan Tan
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Publication number: 20140019097Abstract: Structural parameters of a specimen are determined by fitting models of the response of the specimen to measurements collected by different measurement techniques in a combined analysis. Models of the response of the specimen to at least two different measurement technologies share at least one common geometric parameter. In some embodiments, a model building and analysis engine performs x-ray and optical analyses wherein at least one common parameter is coupled during the analysis. The fitting of the response models to measured data can be done sequentially, in parallel, or by a combination of sequential and parallel analyses. In a further aspect, the structure of the response models is altered based on the quality of the fit between the models and the corresponding measurement data. For example, a geometric model of the specimen is restructured based on the fit between the response models and corresponding measurement data.Type: ApplicationFiled: July 3, 2013Publication date: January 16, 2014Inventors: Michael S. Bakeman, Andrei V. Shchegrov, Qiang Zhao, Zhengquan Tan
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Patent number: 7349079Abstract: A method for measurement of a specimen is provided. The method includes measuring spectroscopic ellipsometric data of the specimen. The method also includes determining a nitrogen concentration of a nitrided oxide gate dielectric formed on the specimen from the spectroscopic ellipsometric data. A computer-implemented method for analysis of a specimen is also provided. This method includes determining a nitrogen concentration of a nitrided oxide gate dielectric formed on the specimen from spectroscopic ellipsometric data generated by measurement of the specimen. In some embodiments, the methods described above may include determining an index of refraction of the nitrided oxide gate dielectric from the spectroscopic ellipsometric data and determining the nitrogen concentration from the index of refraction. In another embodiment, the methods described above may include measuring reflectometric data of the specimen.Type: GrantFiled: May 14, 2004Date of Patent: March 25, 2008Assignee: KLA-Tencor Technologies Corp.Inventors: Qiang Zhao, Torsten Kaack, Sungchul Yoo, Zhengquan Tan
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Patent number: 7196021Abstract: A method for forming a silicon oxide layer over a substrate disposed in a high density plasma substrate processing chamber. The method includes flowing a process gas that includes a silicon-containing source, an oxygen-containing source and a fluorine-containing source into the substrate processing chamber and forming a plasma from said process gas. The substrate is heated to a temperature above 450° C. during deposition of said silicon oxide layer and the deposited layer has a fluorine content of less than 1.0 atomic percent.Type: GrantFiled: March 30, 2005Date of Patent: March 27, 2007Assignee: Applied Materials, Inc.Inventors: Zhengquan Tan, Dongqing Li, Walter Zygmunt
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Patent number: 7159597Abstract: A process for removing unwanted deposition build-up from one or more interior surfaces of a substrate processing chamber after depositing a layer of material over a substrate disposed in the chamber. In one embodiment the process comprises transferring the substrate out of the chamber; flowing a first gas into the substrate processing chamber and forming a plasma within the chamber from the first gas in order to heat the chamber; and thereafter, extinguishing the plasma, flowing an etchant gas into a remote plasma source, forming reactive species from the etchant gas and transporting the reactive species into the substrate processing chamber to etch the unwanted deposition build-up.Type: GrantFiled: May 21, 2002Date of Patent: January 9, 2007Assignee: Applied Materials, Inc.Inventors: Zhong Qiang Hua, Zhengquan Tan, Zhuang Li, Kent Rossman
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Patent number: 7064077Abstract: A method of depositing a high density plasma silicon oxide layer having improved gapfill capabilities. In one embodiment the method includes flowing a process gas consisting of a silicon-containing source, an oxygen-containing source and helium into a substrate processing chamber and forming a plasma from the process gas. The ratio of the flow rate of the helium with respect to the combined flow rate of the silicon source and oxygen source is between 0.5:1 and 3.0:1 inclusive. In one particular embodiment, the process gas consists of monosilane (SiH4), molecular oxygen (O2) and helium.Type: GrantFiled: October 1, 2004Date of Patent: June 20, 2006Assignee: Applied MaterialsInventors: Zhong Qiang Hua, Dong Qing Li, Zhengquan Tan, Zhuang Li, Michael Chiu Kwan, Bruno Geoffrion, Padmanabhan Krishnaraj