Patterning challenges in the fabrication of 12 nm half-pitch dual damascene copper ultra low-k interconnects

Chawla, J. S.; Singh, Kanwal Jit; Myers, Alan M.; Michalak, David J.; Schenker, Richard E.; Jezewski, Christopher; Krist, B.; Gstrein, Florian; Indukuri, Tejaswi; Yoo, Hye Jin

doi:10.1117/12.2048599

Cited by 13 publications

(12 citation statements)

References 11 publications

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“…Traditional photolithographic fabrication methods have started to reach fundamental limits in the size of features they can produce 1–3 and the next generation methods such as extreme ultraviolet lithography 4,5 have many lingering issues needing to be addressed to become economically viable 6,7 . Thus, alternative lithographic methods such as block copolymer (BCP) directed self-assembly (DSA) 8–13 , direct write focused ion or electron beam 14,15 , or other multistep patterning photolithography techniques 16–18 are necessary to continue the trend predicted by Gordon Moore of device density doubling every couple of years 19 . In particular, BCP DSA can be quite prone to defects 20 and poor long-range order 21,22 compared to traditional lithography, and as a result better metrology techniques for measuring the overall order need to be implemented.…”

Section: Introductionmentioning

confidence: 99%

Advancing x-ray scattering metrology using inverse genetic algorithms

Hannon

Sunday

Kline

2016

J. Micro/Nanolith. MEMS MOEMS

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We compare the speed and effectiveness of two genetic optimization algorithms to the results of statistical sampling via a Markov chain Monte Carlo algorithm to find which is the most robust method for determining real space structure in periodic gratings measured using critical dimension small angle X-ray scattering. Both a covariance matrix adaptation evolutionary strategy and differential evolution algorithm are implemented and compared using various objective functions. The algorithms and objective functions are used to minimize differences between diffraction simulations and measured diffraction data. These simulations are parameterized with an electron density model known to roughly correspond to the real space structure of our nanogratings. The study shows that for X-ray scattering data, the covariance matrix adaptation coupled with a mean-absolute error log objective function is the most efficient combination of algorithm and goodness of fit criterion for finding structures with little foreknowledge about the underlying fine scale structure features of the nanograting.

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Section: Introductionmentioning

confidence: 99%

Advancing x-ray scattering metrology using inverse genetic algorithms

Hannon

Sunday

Kline

2016

J. Micro/Nanolith. MEMS MOEMS

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“…501 Such schemes require that all the materials involved have discrete and unique etch selectivities with respect to one another. Understanding all the associated etch selectivity requirements in such schemes is complex.…”

Section: 15mentioning

confidence: 99%

“…498,499 In some cases, 4X multiple patterning schemes are being considered for <22 nm technology nodes. 500 To reduce some of the complexity of such pitch division / multiple pass patterning schemes, new ES / HM materials and deposition processes are being sought that either provide high or contrasting etch selectivities relative to other materials, 501 or can be selectively deposited / grown on pre-existing patterned structures. [502][503][504] The latter is beyond the scope of this article.…”

Section: 15mentioning

confidence: 99%

Dielectric Barrier, Etch Stop, and Metal Capping Materials for State of the Art and beyond Metal Interconnects

King

2014

ECS J. Solid State Sci. Technol.

131

115

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Over the past decade, the primary focus for improving the performance of nano-electronic metal interconnect structures has been to reduce the impact of resistance-capacitance (RC) delays via utilizing insulating dielectrics with ever lower values of dielectric permittivity. The integration and implementation of such low dielectric constant (i.e. low-k) materials has been fraught with numerous challenges. For intermetal and interlayer (ILD) low-k dielectrics, these challenges have been largely associated to integration with metal interconnect fabrication processes and well documented and reviewed in the literature. Although equally important, less attention has been given to other low-k dielectrics utilized in metal interconnect structures that are commonly referred to as low-k dielectric barriers (DB), etch stops (ES), and/or Cu capping layers (CCL). These materials present numerous challenges as well for integration into metal interconnect fabrication processes. However, they also have more stringent integrated functionality requirements relative to low-k ILD materials that serve only a basic purpose of electrically isolating adjacent metal lines. In this article, we review the integration challenges and associated integrated functionality requirements for low-k DB/ES/CCL materials with a focus on the current status and future direction needed for these materials to facilitate both Moore's law (i.e. More Moore) and More than Moore scaling.

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“…The sample had both intentional (a small-variation focus-exposure matrix, or FEM) and unintentional (random natural process) dimensional variation. [48] The measured site was well inside (>500 m from the nearest edge) of a 1 mm by 8 mm densely patterned area.…”

Section: Samplementioning

confidence: 87%

Scanning electron microscope measurement of width and shape of 10 nm patterned lines using a JMONSEL-modeled library

Villarrubia¹,

Vladár²,

Ming³

et al. 2015

Ultramicroscopy

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The width and shape of 10nm to 12 nm wide lithographically patterned SiO2 lines were measured in the scanning electron microscope by fitting the measured intensity vs. position to a physics-based model in which the lines' widths and shapes are parameters. The approximately 32 nm pitch sample was patterned at Intel using a state-of-the-art pitch quartering process. Their narrow widths and asymmetrical shapes are representative of near-future generation transistor gates. These pose a challenge: the narrowness because electrons landing near one edge may scatter out of the other, so that the intensity profile at each edge becomes width-dependent, and the asymmetry because the shape requires more parameters to describe and measure. Modeling was performed by JMONSEL (Java Monte Carlo Simulation of Secondary Electrons), which produces a predicted yield vs. position for a given sample shape and composition. The simulator produces a library of predicted profiles for varying sample geometry. Shape parameter values are adjusted until interpolation of the library with those values best matches the measured image. Profiles thereby determined agreed with those determined by transmission electron microscopy and critical dimension small-angle x-ray scattering to better than 1 nm.

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Patterning challenges in the fabrication of 12 nm half-pitch dual damascene copper ultra low-k interconnects

Cited by 13 publications

References 11 publications

Advancing x-ray scattering metrology using inverse genetic algorithms

Advancing x-ray scattering metrology using inverse genetic algorithms

Dielectric Barrier, Etch Stop, and Metal Capping Materials for State of the Art and beyond Metal Interconnects

Scanning electron microscope measurement of width and shape of 10 nm patterned lines using a JMONSEL-modeled library

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