The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibra...The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibrate the corresponding instruments.We develop a new reference material with nominal CDs of 160 nm,80 nm,and 40 nm.The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology(NIM)in China.Also,we propose a new characterization method for the precise measurement of CD values.After filtering and leveling the intensity profiles,the line features are characterized by the combination model of the Gaussian and Lorentz functions.The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm.Then the width of the two edges at the half intensity position is regarded as the standard CD value.Finally,the measurement results are evaluated in terms of the sample,instrument,algorithm,and repeatability.The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.展开更多
Line width(i.e.,critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control the CD in manufacturing,a reasonable CD measurement algorithm is required.We develop an automatic and accurate ...Line width(i.e.,critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control the CD in manufacturing,a reasonable CD measurement algorithm is required.We develop an automatic and accurate method based on a two-dimensional discrete Fourier transform for measuring the lattice spacings from high-resolution transmission electron microscopy images.Through the two-dimensional inverse discrete Fourier transform of the central spot and a pair of symmetrical diffraction spots,an image containing only a set of lattice spacings is obtained.Then,the pixel span of the lattice spacing is calculated through the centre of gravity method.Finally,we estimate the standard CD value according to the half-intensity method.The silicon crystal lattice constant guarantees the accuracy and traceability of the CD value.Through experiments,we demonstrate the efficiency of the proposed method,which can be conveniently applied to accurately measure CDs in practical applications.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2020YFF0218403)the Basic Scientific Research Operating Fund of NIM(Grant No.AKYZD2007-1)。
文摘The line width(often synonymously used for critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control CD values in manufacturing,a reasonable CD reference material is required to calibrate the corresponding instruments.We develop a new reference material with nominal CDs of 160 nm,80 nm,and 40 nm.The line features are investigated based on the metrological scanning electron microscope which is developed by the National Institute of Metrology(NIM)in China.Also,we propose a new characterization method for the precise measurement of CD values.After filtering and leveling the intensity profiles,the line features are characterized by the combination model of the Gaussian and Lorentz functions.The left and right edges of CD are automatically extracted with the profile decomposition and k-means algorithm.Then the width of the two edges at the half intensity position is regarded as the standard CD value.Finally,the measurement results are evaluated in terms of the sample,instrument,algorithm,and repeatability.The experiments indicate efficiency of the proposed method which can be easily applied in practice to accurately characterize CDs.
基金supported by Basic Scientific Research Operating Fund of NIM(Grant No.AKYZD2007-1).
文摘Line width(i.e.,critical dimension,CD)is a crucial parameter in integrated circuits.To accurately control the CD in manufacturing,a reasonable CD measurement algorithm is required.We develop an automatic and accurate method based on a two-dimensional discrete Fourier transform for measuring the lattice spacings from high-resolution transmission electron microscopy images.Through the two-dimensional inverse discrete Fourier transform of the central spot and a pair of symmetrical diffraction spots,an image containing only a set of lattice spacings is obtained.Then,the pixel span of the lattice spacing is calculated through the centre of gravity method.Finally,we estimate the standard CD value according to the half-intensity method.The silicon crystal lattice constant guarantees the accuracy and traceability of the CD value.Through experiments,we demonstrate the efficiency of the proposed method,which can be conveniently applied to accurately measure CDs in practical applications.
