The Experts below are selected from a list of 294 Experts worldwide ranked by ideXlab platform

Hiroki Kawada - One of the best experts on this subject based on the ideXlab platform.

  • study of Measurement Condition optimization in critical dimension scanning electron microscope
    Japanese Journal of Applied Physics, 2008
    Co-Authors: Keiichiro Hitomi, Yoshinori Nakayama, Hiromasa Yamanashi, Yasunari Sohda, Hiroki Kawada
    Abstract:

    The critical-dimension scanning electron microscope (CD-SEM) is an essential tool for semiconductor fabrication process control because of its high resolution and high precision. However, in ArF lithography, the CD of resist changes during CD-SEM Measurement due to shrinkage caused by the electron beam irradiation. This shrinkage can be reduced by Measurement parameters; however, there is a trade-off relationship between shrinkage and precision. Thus, measuring the CD of an ArF resist pattern precisely with small shrinkage is difficult. The authors propose an optimization method using the Taguchi method. Four Measurement parameters were chosen as control factors for an L18 orthogonal array: probe current, acceleration voltage, horizontal length of field-of-view, and number of image acquisitions. As a result, high prediction accuracy was obtained that is smaller than 0.2 nm for shrinkage and 0.1 nm for precision. Moreover, an optimum Measurement Condition that achieves 0.28 nm shrinkage and 0.37 nm precision was also obtained. Thus, the proposed method was demonstrated as a promising method to optimize CD Measurement parameters.

  • Novel Method for Measurement Condition Optimization in CD-SEM
    2007 Digest of papers Microprocesses and Nanotechnology, 2007
    Co-Authors: Keiichiro Hitomi, Yoshinori Nakayama, Hiromasa Yamanashi, Yasunari Sohda, Hiroki Kawada
    Abstract:

    This paper introduces the Taguchi method for the optimization of Measurement Conditions in critical dimension-scanning electron microscope (CD-SEM). As a result, four parameter Conditions are optimized for low resist shrinkage and highly precise Measurement through eighteen experiments. The prediction accuracy is under 0.2 nm. Moreover, high prediction accuracy is obtained for three different ArF resists. Therefore, it is clarified that the proposed method is a promising tool for CD-Measurement optimization.

Keiichiro Hitomi - One of the best experts on this subject based on the ideXlab platform.

  • Methodology for determining critical dimension scanning electron microscope Measurement Condition of sub-20 nm resist patterns for 0.33 NA extreme ultraviolet lithography
    Journal of Micro-nanolithography Mems and Moems, 2016
    Co-Authors: Nobuhiro Okai, Keiichiro Hitomi, Erin Lavigne, Scott Halle, Shoji Hotta, Shunsuke Koshihara, Junichi Tanaka, Atsuko Yamaguchi, Todd C. Bailey
    Abstract:

    A methodology to determine the optimum Measurement Condition of extreme ultraviolet (EUV) resist patterns in a critical dimension scanning electron microscope has been established. Along with many parameters that need to be optimized simultaneously, there are conflicting requirements of small resist shrinkage and high Measurement precision. To overcome these difficulties, we have developed a methodology for ArF resist patterns from shrinkages and precisions predicted by the Taguchi method. In this study, we examined the extendibility of the methodology to sub-20 nm EUV resist patterns. The predicted shrinkage by the Taguchi method for an 18 nm EUV resist pattern showed a large prediction error due to its different dependence on acceleration voltage from ArF, so we used the shrinkage curve to predict shrinkage instead of the Taguchi method, as shrinkage depends only on irradiated electron dose. In contrast, precision can be predicted well by the Taguchi method as with ArF. We propose a methodology that consists of separate prediction procedures for shrinkage and precision using the shrinkage curve and Taguchi method, respectively. The proposed method was applied to an 18-nm EUV resist pattern. The optimum Measurement Condition with shrinkage of 1.5 nm and precision of 0.12 nm was determined.

  • Methodology for determining CD-SEM Measurement Condition of sub-20nm resist patterns for 0.33NA EUV lithography
    Proceedings of SPIE, 2015
    Co-Authors: Nobuhiro Okai, Keiichiro Hitomi, Erin Lavigne, Scott Halle, Shoji Hotta, Shunsuke Koshihara, Junichi Tanaka, Todd C. Bailey
    Abstract:

    A novel methodology was established for determining critical dimension scanning electron microscope (CD-SEM) optimum Measurement Condition of sub-20 nm resist patterns for 0.33NA EUV lithography yielding both small shrinkage and high precision. To investigate dependency of resist shrinkage on pattern size and electron beam irradiation Condition, shrinkage of 18, 32, and 45 nm EUV resist patterns was measured over a wide range of beam Conditions. A shrinkage trend similar to that of ArF resist patterns was observed for 32 and 45 nm, but 18 nm pattern showed a different dependence on acceleration voltage. Conventional methodology developed for ArF resist pattern to predict shrinkage and precision using the Taguchi method was applied to EUV resist pattern to examine the extendibility of the method. Predicted shrinkage by Taguchi method for 32 and 45 nm patterns agreed with Measurements. However, the prediction error increases considerably as the pattern size decreases from 32 to 18 nm because there is a significant interaction between acceleration voltage and irradiated electron dose in L18 array used in the Taguchi method. Thus, we proposed a new method that consists of separated prediction procedures of shrinkage and precision using both a shrinkage curve and the Taguchi method, respectively. The new method was applied to 18 nm EUV resist pattern, and the optimum Measurement Condition with shrinkage of 1.5 nm and precision of 0.12 nm was determined. Our new method is a versatile technique which is applicable not only to fine EUV resist pattern but also to ArF resist pattern.

  • study of Measurement Condition optimization in critical dimension scanning electron microscope
    Japanese Journal of Applied Physics, 2008
    Co-Authors: Keiichiro Hitomi, Yoshinori Nakayama, Hiromasa Yamanashi, Yasunari Sohda, Hiroki Kawada
    Abstract:

    The critical-dimension scanning electron microscope (CD-SEM) is an essential tool for semiconductor fabrication process control because of its high resolution and high precision. However, in ArF lithography, the CD of resist changes during CD-SEM Measurement due to shrinkage caused by the electron beam irradiation. This shrinkage can be reduced by Measurement parameters; however, there is a trade-off relationship between shrinkage and precision. Thus, measuring the CD of an ArF resist pattern precisely with small shrinkage is difficult. The authors propose an optimization method using the Taguchi method. Four Measurement parameters were chosen as control factors for an L18 orthogonal array: probe current, acceleration voltage, horizontal length of field-of-view, and number of image acquisitions. As a result, high prediction accuracy was obtained that is smaller than 0.2 nm for shrinkage and 0.1 nm for precision. Moreover, an optimum Measurement Condition that achieves 0.28 nm shrinkage and 0.37 nm precision was also obtained. Thus, the proposed method was demonstrated as a promising method to optimize CD Measurement parameters.

  • Novel Method for Measurement Condition Optimization in CD-SEM
    2007 Digest of papers Microprocesses and Nanotechnology, 2007
    Co-Authors: Keiichiro Hitomi, Yoshinori Nakayama, Hiromasa Yamanashi, Yasunari Sohda, Hiroki Kawada
    Abstract:

    This paper introduces the Taguchi method for the optimization of Measurement Conditions in critical dimension-scanning electron microscope (CD-SEM). As a result, four parameter Conditions are optimized for low resist shrinkage and highly precise Measurement through eighteen experiments. The prediction accuracy is under 0.2 nm. Moreover, high prediction accuracy is obtained for three different ArF resists. Therefore, it is clarified that the proposed method is a promising tool for CD-Measurement optimization.

Shinobu Fujita - One of the best experts on this subject based on the ideXlab platform.

  • The effect of local structure and non-uniformity on decoherence-free states of charge qubits
    Physica E-low-dimensional Systems & Nanostructures, 2006
    Co-Authors: Tetsufumi Tanamoto, Shinobu Fujita
    Abstract:

    We analyze robustness of decoherence-free (DF) subspace in charge qubits when there are local structure and non-uniformity that violate collective decoherence Measurement Condition. We solve master equations of up to four charge qubits and a detector as two serially coupled quantum point contacts (QPC) with an island structure. We show that robustness of DF states is strongly affected by local structure as well as by non-uniformities of qubits.

  • Decoherence-free states for charge qubits under local nonuniformity
    Physical Review B, 2005
    Co-Authors: Tetsufumi Tanamoto, Shinobu Fujita
    Abstract:

    We analyze the robustness of a decoherence-free (DF) subspace and subsystem in charge qubits, when the difference from the collective decoherence Measurement Condition is large $(\ensuremath{\sim}5%)$ in the long time period, which is applicable for solid-state qubits using as a quantum memory. We solve master equations of up to four charge qubits and a detector as a quantum point contact. We show that robustness of DF states is strongly affected by local nonuniformities. We also discuss the possible two-qubit logical states by exactly solving the master equations.

Theodore F. Morse - One of the best experts on this subject based on the ideXlab platform.

  • Fiber optic microbend sensor for distributed sensing application in the structural strain monitoring
    Sensors and Actuators A: Physical, 1999
    Co-Authors: Fei Luo, Naibing Ma, Jingyuan Liu, Theodore F. Morse
    Abstract:

    A fiber optic microbend sensor with an elastic, arched sensing diaphragm has been developed for structural strain Measurement. The combination of multiple microbend sensors can form a sensor array for the quasi-distributed sensing application in the monitoring of local strain or deformation along structures, and the optical time domain reflectometry can be conveniently used for interrogation of each sensor unit. The sensor sensitivity can be set at a specific value according to the requirements of the Measurement Condition. Connected with multiplexed sensing processing schemes, the sensor array may find an application in the real-time monitoring and damage detection of large and critical engineering structures.

Steffen Leonhardt - One of the best experts on this subject based on the ideXlab platform.

  • A versatile Body Sensor Network for health care applications
    2009 International Conference on Intelligent Sensors Sensor Networks and Information Processing (ISSNIP), 2009
    Co-Authors: L. Beckmann, Moritz Pistor, Linda Cousin, Marian Walter, Steffen Leonhardt
    Abstract:

    This paper presents the development of a Body Sensor Network, called the meditBSN, for health monitoring applications. It is designed around a MSP430F1611 micr meditBSN ocontroller and a CC1101 433 MHz ISM band transceiver IC. A Bioimpedance Spectroscopy Measurement Condition monitoring application has been developed using the meditBSN. It incorporates three 3-D accelerometers and a skin temperature probe. Additionally, a PDA software was developed to control BIS Measurements as well as to analyze and save the data from the meditBSN.

  • A versatile Body Sensor Network for health care applications
    Intelligent Sensors Sensor Networks and Information Processing (ISSNIP) 2009 5th International Conference on, 2009
    Co-Authors: Saim Kim, Moritz Pistor, Linda Cousin, L. Beckmann, Marian Walter, Steffen Leonhardt
    Abstract:

    This paper presents the development of a Body Sensor Network, called the meditBSN, for health monitoring applications. It is designed around a MSP430F1611 microcontroller and a CC1101 433 MHz ISM band transceiver IC. A Bioimpedance Spectroscopy Measurement Condition monitoring application has been developed using the meditBSN. It incorporates three 3-D accelerometers and a skin temperature probe. Additionally, a PDA software was developed to control BIS Measurements as well as to analyze and save the data from the meditBSN.