Resist roughness evaluation and frequency analysis: metrological challenges and potential solutions for extreme ultraviolet lithography

Pret, Alessandro Vaglio; Gronheid, Roel; Ishimoto, Toru; Sekiguchi, Kohei

doi:10.1117/1.3531982

Cited by 23 publications

(8 citation statements)

References 28 publications

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“…The evolution of the true LWR at each technological step is represented in Fig. [20][21][22][23][24] As VUV-cured resist patterns present almost no more high frequency components (Fig. The first observation is that the LWR decreases during Si ARC and SOC etching steps, while the SOC LWR is identically transferred into the polysilicon layer during the polysilicon etching for the three experiments.…”

Section: Plasma Etching Transfer Of Hbr and Vuv-cured Resist Patternsmentioning

confidence: 99%

Plasma treatments to improve line-width roughness during gate patterning

Azarnouche

Pargon²,

Menguelti³

et al. 2013

J. Micro/Nanolith. MEMS MOEMS

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The major issue related to line width roughness (LWR) is the significant LWR of the photoresist patterns printed by 193-nm lithography that is partially transferred into the gate stack during the subsequent plasma etching steps. The strategy used today to overcome this issue is to apply postlithography treatments to reduce photoresist pattern LWR before transfer. In this article, we investigate the impact of various plasma treatments (HBr, H 2 , He, Ar) on the minimization of the LWR of dense and isolated photoresist patterns and its transfer during gate patterning. To do so, we use critical dimension scanning electron microscopy measurements combined with power spectrum density fitting method to extract unbiased LWR values and provide a spectral analysis of the LWR. We show that plasma treatments that lead to carbon redeposition from the gas phase on the resist pattern sidewalls are less efficient to reduce LWR than plasma treatments where the redeposition is limited. Among all plasma chemistries, H 2 plasmas seem very promising to decrease resist LWR in the whole spectral range, while maintaining square resist profiles. In addition, we show that all frequency roughness components are not equally transferred during gate patterning, and more particularly that the high frequency roughness components are lost.

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Section: Plasma Etching Transfer Of Hbr and Vuv-cured Resist Patternsmentioning

confidence: 99%

Plasma treatments to improve line-width roughness during gate patterning

Azarnouche

Pargon²,

Menguelti³

et al. 2013

J. Micro/Nanolith. MEMS MOEMS

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show abstract

“…5,17 Cho et al 11 have demonstrated that the resist reflow process (RRP) could decrease LWR/LER down to 1 nm, using Monte Carlo simulation. 5,17 Cho et al 11 have demonstrated that the resist reflow process (RRP) could decrease LWR/LER down to 1 nm, using Monte Carlo simulation.…”

Section: Introductionmentioning

confidence: 99%

“…5,17 Cho et al 11 have demonstrated that the resist reflow process (RRP) could decrease LWR/LER down to 1 nm, using Monte Carlo simulation. By adjusting the bake temperature, Pret et al 5,10 obtained a 10% LWR reduction while maintaining the resist CD. 18 RRP successfully smoothes the resist surface, but at the cost of an increase in the critical dimension of the pattern.…”

Section: Introductionmentioning

confidence: 99%

Smoothing mechanisms involved in thermal treatment for linewidth roughness reduction of 193-nm photoresist patterns

Pargon¹,

Azarnouche²,

Fouchier³

et al. 2013

Journal of Vacuum Science & Technology B, Nanotechnology an

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“…[3][4][5][6][7][8][9][10] Such processes have been shown to reduce the high-frequency roughness and the overall 3σ of the roughness. For extreme ultraviolet lithography in particular, reducing LWR has been a vexing problem, with resist LWR on the order of 4 to 5 nm (3σ), 1 but with requirements of less than 2 nm (12% of the physical gate length, according to the International Technology Roadmap for Semiconductors 2 ).…”

Section: Introductionmentioning

confidence: 99%

Understanding the efficacy of linewidth roughness postprocessing

Mack¹

2015

J. Micro/Nanolith. MEMS MOEMS

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Lack of progress in reducing linewidth roughness of lithographic features has led to investigations of the use of postlithography process smoothing techniques. However, it remains unclear whether such postprocessing will sufficiently reduce the detrimental effects of feature roughness. Thus, there is a need to understand the efficacy of postprocessing on not just roughness reduction, but on the negative device impacts of roughness. We derive model equations of how roughness impacts lithographic performance and incorporates smoothing using postprocessing. These models clearly show that postprocess smoothing works best by increasing the correlation length. Increasing the correlation length is very effective at reducing high-frequency roughness that impacts within-feature variations but is less effective at reducing low-frequency roughness that impacts feature-to-feature variations. It seems that postprocess smoothing is not a substitute for reducing the initial roughness of resist features. Mack: Understanding the efficacy of linewidth roughness postprocessing Downloaded From: http://nanolithography.spiedigitallibrary.org/ on 08/20/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Mack: Understanding the efficacy of linewidth roughness postprocessing Downloaded From: http://nanolithography.spiedigitallibrary.org/ on 08/20/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Mack: Understanding the efficacy of linewidth roughness postprocessing Downloaded From: http://nanolithography.spiedigitallibrary.org/ on 08/20/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Mack: Understanding the efficacy of linewidth roughness postprocessing Downloaded From: http://nanolithography.spiedigitallibrary.org/ on 08/20/2015 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

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Resist roughness evaluation and frequency analysis: metrological challenges and potential solutions for extreme ultraviolet lithography

Cited by 23 publications

References 28 publications

Plasma treatments to improve line-width roughness during gate patterning

Plasma treatments to improve line-width roughness during gate patterning

Smoothing mechanisms involved in thermal treatment for linewidth roughness reduction of 193-nm photoresist patterns

Understanding the efficacy of linewidth roughness postprocessing

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