Spectroscopic ellipsometry and reflectometry from gratings (Scatterometry) for critical dimension measurement and in situ, real-time process monitoring

Huang, Hsu Ting; Terry, Fred L.

doi:10.1016/j.tsf.2004.04.010

Cited by 118 publications

(57 citation statements)

References 12 publications

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“…Some of the most widely used configurations are single incidence angle reflectometry, 2-Θ scatterometry, spectroscopic ellipsometry, Fourier scatterometry, interferometric Fourier scatterometry,etc., [7][8][9][10][11][12][13][14][15] with a wide range of applications [16][17][18][19][20]. In an earlier paper, it has been predicted theoretically how, and under which conditions, CFS can be more sensitive than the classical IOS [21].…”

Section: Introductionmentioning

confidence: 99%

Reconstruction of sub-wavelength features and nano-positioning of gratings using coherent Fourier scatterometry

et al. 2014

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Abstract:Optical scatterometry is the state of art optical inspection technique for quality control in lithographic process. As such, any boost in its performance carries very relevant potential in semiconductor industry. Recently we have shown that coherent Fourier scatterometry (CFS) can lead to a notably improved sensitivity in the reconstruction of the geometry of printed gratings. In this work, we report on implementation of a CFS instrument, which confirms the predicted performances. The system, although currently operating at a relatively low numerical aperture (NA = 0.4) and long wavelength (633 nm) allows already the reconstruction of the grating parameters with nanometer accuracy, which is comparable to that of AFM and SEM measurements on the same sample, used as reference measurements. Additionally, 1 nm accuracy in lateral positioning has been demonstrated, corresponding to 0.08% of the pitch of the grating used in the actual experiment.

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Section: Introductionmentioning

confidence: 99%

Reconstruction of sub-wavelength features and nano-positioning of gratings using coherent Fourier scatterometry

et al. 2014

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“…In order to test the sensitivity to changes in the line width (critical dimensions) of the copper lines, the simulated grating structure is based on copper metal lines with a barrier layer between the copper and the dielectric. We will use an implementation of rigorous coupled wave analysis (RCWA) which has already been used as an accurate simulation tool of non-destructive optical measurements of periodic grating structures [9], [10]. Additionally, there has been good agreement between RCWA and critical dimension (CD) measurements [11] and plasmon effects [12].…”

Section: Introductionmentioning

confidence: 99%

Enhancing one dimensional sensitivity with plasmonic coupling

O’Mullane¹,

Peterson²,

Race³

et al. 2014

Opt. Express

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In this paper, we propose a cross-grating structure to enhance the critical dimension sensitivity of one dimensional nanometer scale metal gratings. Making use of the interaction between slight changes in refractive index and localized plasmons, we demonstrate sub-angstrom scale sensitivity in this structure. Compared to unaltered infinite metal gratings and truncated finite gratings, this cross-grating structure shows robust spectra dependent mostly on the dimension of the smaller line width and pitch. While typical scatterometry simulations show angstrom resolution at best, this structure has demonstrated picometer resolution. Due to the wide range of acceptable specifications, we expect experimental confirmation of such structures to soon follow.

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“…Figure 8 shows the variation of the depths of TSV arrays of nominal 5,10,15,20,25, and 30 μm CDs with the measured die-to-die as a function of position across a 200-mm-diameter test wafer. The uniformity of via depth is defined as Uniformity AE 100% ¼ depth max − depth min depth ave: × 2 × 100%: (11) Currently developed etching process recipes have enabled efficient anisotropic etching and an etch rate >50 μm∕ min. As the Si etch rate increases, the ability to control the wafer temperature becomes crucial to obtaining a uniform etch across the wafer.…”

Section: Resultsmentioning

confidence: 99%

“…[9][10][11][12][13] The normalincidence spectral reflectometer is an excellent tool for the characterization of TSV depths and shapes. Horie et al developed a UV-reflectometry technique for fast trenchdepth measurement.…”

Section: Introductionmentioning

confidence: 99%

Spectral reflectometry for metrology of three-dimensional through-silicon vias

2014

J. Micro/Nanolith. MEMS MOEMS

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Abstract. The technology for semiconductor device packaging is rapidly advancing in response to increasing demand for smaller and thinner electronic devices. Three-dimensional chip stacking that uses through-silicon vias (TSVs) is a key area of technical focus, and the high-density TSV (HDTSV) is a major enabler of threedimensional (3-D) integrated circuit technology. The ongoing development of this novel technology has created a need for noncontact characterization. One of the main challenges for 3-D TSV metrology is measuring high aspect ratio features that limit conventional optical microscopy techniques. We demonstrate the use and enhancement of an existing wafer metrology tool, a spectral reflectometer, by developing and implementing theoretical models and measurement algorithms for inspection of HDTSVs. It is capable of measuring the depth of vias, and can also be used for the estimation of bottom roughness and bottom shapes of vias through the model fitting. Our nondestructive solution has measured TSV diameters as small as 3 μm and aspect ratios >16.5∶1. Submicron depth measurement accuracy has been verified in the range of 30 to 60 μm on via depth. Metrology results from actual wafers formed from 3-D interconnect processing are presented. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Spectroscopic ellipsometry and reflectometry from gratings (Scatterometry) for critical dimension measurement and in situ, real-time process monitoring

Cited by 118 publications

References 12 publications

Reconstruction of sub-wavelength features and nano-positioning of gratings using coherent Fourier scatterometry

Reconstruction of sub-wavelength features and nano-positioning of gratings using coherent Fourier scatterometry

Enhancing one dimensional sensitivity with plasmonic coupling

Spectral reflectometry for metrology of three-dimensional through-silicon vias

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