Xinhui Niu | UC Berkeley (original) (raw)

Papers by Xinhui Niu

Research paper thumbnail of Scatterometry for contact hole lithography

Proceedings of SPIE, May 24, 2004

Scatterometry has been most commonly applied to CD metrology of line/space grating structures. Ho... more Scatterometry has been most commonly applied to CD metrology of line/space grating structures. However, for the process development and control of 3D structures for contact hole lithography applications, the current metrology methods of CD-SEM, electrical CD (ECD) and/or cross-sectional SEM (X-SEM) produce the desired information either (a) as an incomplete solution, (b) too late in process flow, or (c) in a destructive manner. In this paper, we will present use cases for the application of scatterometry to 3D structures, i.e., post-lithography hole/space patterns, where measurements of CD, profile, and film thickness can be made immediately following the lithography process, in a method nondestructive to the wafer. These use cases demonstrate the capability of 3D metrology integrated onto a TEL Clean Track platform, where a Therma-Wave reflectometer was used to generate spectra that were then processed via Timbre ODP, for a film stack of patterned photoresist (PR), anti-reflective coating (ARC), and oxide on top of a silicon (Si) substrate. Focus-Exposure Matrix (FEM) wafers have also been produced in order to characterize the contact hole profile and CD variation as a result of changing focus and exposure conditions. The results of the experiment show that ODP can be used successfully to monitor CD, film thickness, and profile variation, providing a valuable solution to contact hole lithography. Tool precision and matching results are also shown, which indicate the stability of the measurement process, and correlation to CD-SEM is also provided as a reference metrology. These results suggest that integrated 3D scatterometry is a viable production metrology solution, enabling the progression toward Advanced Process Control (APC).

Research paper thumbnail of Optical digital profilometry applications on contact holes

Proceedings of SPIE, May 27, 2003

Optical scatterometry and Optical Digital Profiling (ODP) have become mainstream technology in CD... more Optical scatterometry and Optical Digital Profiling (ODP) have become mainstream technology in CD and profile metrology. Without question, the extension of these techniques to measure three-dimensional patterns such as contact holes or posts is an important demand. In this paper, we demonstrate the application of ODP to contact holes and posts for both lithography and etch processes. The underlying theory based on the Rigorous Coupled Wave Approach (RCWA) is outlined and metrology results are compared with simulations.

Research paper thumbnail of Agilent Technologies

highlighting technical creativity, innovation, and potential impact

Research paper thumbnail of Benützung eines vorspeichers in intraschichtberechnungen für schnellen rigorösen analysen von gekoppelten wellenn

Research paper thumbnail of Motifs de test de reseau et procedes de metrologie de recouvrement

L'invention concerne une metrologie permettant de determiner un biais ou une erreur de recouv... more L'invention concerne une metrologie permettant de determiner un biais ou une erreur de recouvrement dans des procedes lithographiques. Cette metrologie comprend un ensemble de motifs de test de diffraction, des techniques d'inspection optique a l'aide d'ellipsometre ou de reflectometre spectroscopique, et un procede d'extraction de profil de motif de test. L'invention utilise un ensemble de reseaux de diffraction (10) en tant que motifs de test, ainsi qu'un equipement de metrologie pour couche mince, notamment un ellipsometre ou un reflectometre spectroscopique. Les profils des motifs de test dans les deux couches successives sont analyses. On obtient des informations de recouvrement apres traitement des donnees des profils. Dans une premiere realisation de l'invention, on met en oeuvre une structure de motifs de test de reseau de recouvrement ligne a ligne dans laquelle un masque de seconde couche est place au centre d'une ligne claire d'un m...

Research paper thumbnail of Interface generique pour systeme de metrologie optique

L'invention concerne un systeme de metrologie optique qui comprend un dispositif photometriqu... more L'invention concerne un systeme de metrologie optique qui comprend un dispositif photometrique presentant une source concue pour generer et diriger de lumiere sur une structure, et un detecteur concu pour detecter de la lumiere diffractee depuis ladite structure et pour convertir la lumiere detectee en un signal de diffraction mesure. Un module de traitement de ce systeme de metrologie optique est concu pour recevoir le signal de diffraction mesure provenant du detecteur afin d'analyser ladite structure. Ledit systeme de metrologie optique comprend egalement une interface generique disposee entre le dispositif photometrique et le module de traitement. Cette interface generique est concu pour fournir le signal de diffraction mesure au module de traitement au moyen d'un ensemble standard de parametres de signal. Cet ensemble standard de parametres de signal comprend un parametre de facteur de reflexion qui caracterise le changement en intensite de lumiere lorsque cette der...

Research paper thumbnail of Overlay measurements using periodic gratings

Research paper thumbnail of System and method for efficient simulation of reflectometry response from two-dimensional grating structures

Research paper thumbnail of Method and Apparatus for the Determination of Mask Rules Using Scatterometry

Research paper thumbnail of Measurement of metal electroplating and seed layer thickness and profile

Research paper thumbnail of Method and system for dynamic learning through a regression-based library generation process

Research paper thumbnail of Shape roughness measurement in optical metrology

Research paper thumbnail of Erzeugung von simulierten Beugungssignalen für zweidimensionale Strukturen

Research paper thumbnail of Modell- und Parameterauswahl für die optische Metrologie

Research paper thumbnail of Model optimization for structures with additional materials

Research paper thumbnail of Method and system of dynamic learning through a regression-based library generation process

Research paper thumbnail of Combined optical profilometry and projection microscopy of integrated circuit structures

Research paper thumbnail of Overlay measurements using zero-order cross polarization measurements

Research paper thumbnail of Approximating eigensolutions for use in determining the profile of a structure formed on a semiconductor wafer

Research paper thumbnail of An integrated system of optical metrology for deep sub-micron lithography

PhiPAC project, which gave me more insight about BLAS. Rich Vudoc offered help on choosing the fi... more PhiPAC project, which gave me more insight about BLAS. Rich Vudoc offered help on choosing the fine-tuned numerical libraries. I thank Eric B. Grann for lending his Ph.D. thesis to me. I also thank Professor Jim Moharam and Philippe Lalanne for answering several questions on RCWA overtelephone and e-mail. I have received support from a lot of people in the semiconductor industry. I thank Joe Bendik, Matt Hankinson, Bob Socha, Ron Kovacs of National Semiconductor for their insights and collaboration. I am grateful to CihanTinaztepeof KLA-Tencor for the summer intemship in 1997. Craig MacNaughton and Anthea Ip of KLA-Tencor helped me with some experimental measurements.

Research paper thumbnail of Scatterometry for contact hole lithography

Proceedings of SPIE, May 24, 2004

Scatterometry has been most commonly applied to CD metrology of line/space grating structures. Ho... more Scatterometry has been most commonly applied to CD metrology of line/space grating structures. However, for the process development and control of 3D structures for contact hole lithography applications, the current metrology methods of CD-SEM, electrical CD (ECD) and/or cross-sectional SEM (X-SEM) produce the desired information either (a) as an incomplete solution, (b) too late in process flow, or (c) in a destructive manner. In this paper, we will present use cases for the application of scatterometry to 3D structures, i.e., post-lithography hole/space patterns, where measurements of CD, profile, and film thickness can be made immediately following the lithography process, in a method nondestructive to the wafer. These use cases demonstrate the capability of 3D metrology integrated onto a TEL Clean Track platform, where a Therma-Wave reflectometer was used to generate spectra that were then processed via Timbre ODP, for a film stack of patterned photoresist (PR), anti-reflective coating (ARC), and oxide on top of a silicon (Si) substrate. Focus-Exposure Matrix (FEM) wafers have also been produced in order to characterize the contact hole profile and CD variation as a result of changing focus and exposure conditions. The results of the experiment show that ODP can be used successfully to monitor CD, film thickness, and profile variation, providing a valuable solution to contact hole lithography. Tool precision and matching results are also shown, which indicate the stability of the measurement process, and correlation to CD-SEM is also provided as a reference metrology. These results suggest that integrated 3D scatterometry is a viable production metrology solution, enabling the progression toward Advanced Process Control (APC).

Research paper thumbnail of Optical digital profilometry applications on contact holes

Proceedings of SPIE, May 27, 2003

Optical scatterometry and Optical Digital Profiling (ODP) have become mainstream technology in CD... more Optical scatterometry and Optical Digital Profiling (ODP) have become mainstream technology in CD and profile metrology. Without question, the extension of these techniques to measure three-dimensional patterns such as contact holes or posts is an important demand. In this paper, we demonstrate the application of ODP to contact holes and posts for both lithography and etch processes. The underlying theory based on the Rigorous Coupled Wave Approach (RCWA) is outlined and metrology results are compared with simulations.

Research paper thumbnail of Agilent Technologies

highlighting technical creativity, innovation, and potential impact

Research paper thumbnail of Benützung eines vorspeichers in intraschichtberechnungen für schnellen rigorösen analysen von gekoppelten wellenn

Research paper thumbnail of Motifs de test de reseau et procedes de metrologie de recouvrement

L'invention concerne une metrologie permettant de determiner un biais ou une erreur de recouv... more L'invention concerne une metrologie permettant de determiner un biais ou une erreur de recouvrement dans des procedes lithographiques. Cette metrologie comprend un ensemble de motifs de test de diffraction, des techniques d'inspection optique a l'aide d'ellipsometre ou de reflectometre spectroscopique, et un procede d'extraction de profil de motif de test. L'invention utilise un ensemble de reseaux de diffraction (10) en tant que motifs de test, ainsi qu'un equipement de metrologie pour couche mince, notamment un ellipsometre ou un reflectometre spectroscopique. Les profils des motifs de test dans les deux couches successives sont analyses. On obtient des informations de recouvrement apres traitement des donnees des profils. Dans une premiere realisation de l'invention, on met en oeuvre une structure de motifs de test de reseau de recouvrement ligne a ligne dans laquelle un masque de seconde couche est place au centre d'une ligne claire d'un m...

Research paper thumbnail of Interface generique pour systeme de metrologie optique

L'invention concerne un systeme de metrologie optique qui comprend un dispositif photometriqu... more L'invention concerne un systeme de metrologie optique qui comprend un dispositif photometrique presentant une source concue pour generer et diriger de lumiere sur une structure, et un detecteur concu pour detecter de la lumiere diffractee depuis ladite structure et pour convertir la lumiere detectee en un signal de diffraction mesure. Un module de traitement de ce systeme de metrologie optique est concu pour recevoir le signal de diffraction mesure provenant du detecteur afin d'analyser ladite structure. Ledit systeme de metrologie optique comprend egalement une interface generique disposee entre le dispositif photometrique et le module de traitement. Cette interface generique est concu pour fournir le signal de diffraction mesure au module de traitement au moyen d'un ensemble standard de parametres de signal. Cet ensemble standard de parametres de signal comprend un parametre de facteur de reflexion qui caracterise le changement en intensite de lumiere lorsque cette der...

Research paper thumbnail of Overlay measurements using periodic gratings

Research paper thumbnail of System and method for efficient simulation of reflectometry response from two-dimensional grating structures

Research paper thumbnail of Method and Apparatus for the Determination of Mask Rules Using Scatterometry

Research paper thumbnail of Measurement of metal electroplating and seed layer thickness and profile

Research paper thumbnail of Method and system for dynamic learning through a regression-based library generation process

Research paper thumbnail of Shape roughness measurement in optical metrology

Research paper thumbnail of Erzeugung von simulierten Beugungssignalen für zweidimensionale Strukturen

Research paper thumbnail of Modell- und Parameterauswahl für die optische Metrologie

Research paper thumbnail of Model optimization for structures with additional materials

Research paper thumbnail of Method and system of dynamic learning through a regression-based library generation process

Research paper thumbnail of Combined optical profilometry and projection microscopy of integrated circuit structures

Research paper thumbnail of Overlay measurements using zero-order cross polarization measurements

Research paper thumbnail of Approximating eigensolutions for use in determining the profile of a structure formed on a semiconductor wafer

Research paper thumbnail of An integrated system of optical metrology for deep sub-micron lithography

PhiPAC project, which gave me more insight about BLAS. Rich Vudoc offered help on choosing the fi... more PhiPAC project, which gave me more insight about BLAS. Rich Vudoc offered help on choosing the fine-tuned numerical libraries. I thank Eric B. Grann for lending his Ph.D. thesis to me. I also thank Professor Jim Moharam and Philippe Lalanne for answering several questions on RCWA overtelephone and e-mail. I have received support from a lot of people in the semiconductor industry. I thank Joe Bendik, Matt Hankinson, Bob Socha, Ron Kovacs of National Semiconductor for their insights and collaboration. I am grateful to CihanTinaztepeof KLA-Tencor for the summer intemship in 1997. Craig MacNaughton and Anthea Ip of KLA-Tencor helped me with some experimental measurements.