Optimization of lithography process to improve image deformation of contact hole sub-90 nm technology node

Jun, Sungho; Kim, Ju-Hyun; Jeong, Eunsoo; Yun, Young-Je; Kim, Jaehee; Kim, Keeho

doi:10.1117/12.711978

Cited by 5 publications

(6 citation statements)

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“…Regarding CER, one can find in literature few papers which use conventional AFM for the characterization of the sidewall roughness of photonic crystal holes [5], while no work has been done on scatterometry. In this work, we follow the main trend and use top-down SEM images as input in CER evaluation methodology [1][2][3][6][7][8][9]. The steps of this methodology are shown schematically in Fig.…”

Section: Cer Evaluation Methodologymentioning

confidence: 99%

Contact edge roughness (CER) characterization and modeling: effects of dose on CER and critical dimension (CD) variation

et al. 2011

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In this paper, we present a methodology for the characterization of Contact Edge Roughness (CER) using top-down SEM images and an algorithm for the generation of model contact edges with controlled roughness as well as synthesized SEM images with CER. The characterization methodology is applied to the determination of the effects of exposure dose on the amplitude and frequency parameters of the CER of an EUV resist, while the model edges are used for understanding the results and connecting RMS to CD variation. Experiments show us that the RMS value of CER decreases as dose decreases contrary to what happens to LER/LWR. Modeling shows that RMS decreases and CD variation increases as the sampled edge length is decreased, in agreement with LER/LWR. Thus, modelling may offer an explanation of the RMS reduction with reduced dose: Indeed, decrease of dose causes reduction of Critical Dimension (CD) (i.e. diameter) of the hole and therefore reduction of its circumference (i.e. measurement edge length), which in turn causes reduction of RMS and increase in CD variation.

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Section: Cer Evaluation Methodologymentioning

confidence: 99%

Contact edge roughness (CER) characterization and modeling: effects of dose on CER and critical dimension (CD) variation

et al. 2011

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“…The involvement of edge length effects in CER process and material dependencies is not clear and more investigations are needed. Nevertheless, the literature devoted to the process effects on CER is very limited and to our knowledge very few works have been reported on exposure-dose effects [5,9]. In previous work, we studied the effects of exposure dose on CER parameters and recalled the edge length effects to explain the difference with LER behavior characterized by the well-known RLS trade off [15,19].…”

Section: Introductionmentioning

confidence: 95%

Contact edge roughness and CD uniformity in EUV: effect of photo acid generator and sensitizer

et al. 2012

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One of the main challenges for developing EUV resists is to satisfy sidewall roughness to allowable limit. With concern of this challenge, in this paper we study the effects of PAG and sensitizer concentration on the CD variation and roughness of contact holes in a EUV resist for a range of exposure doses by applying an advanced characterization methodology. It is found that the contact edge roughness(CER) parameters(RMS, ξ) merge when they are plotted versus the final CD value revealing the critical role of contact CD in the dependence of CER on PAG and sensitizer. This finding means that for specific target CD, different PAG and sensitizer concentrations modify only slightly contact edge roughness parameters. Power spectrum analysis reveals the importance of low frequency edge undulations in RMS dependence on CD. In addition, we found that CD Variation increase with sensitizer concentration.

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“…[8][9][10] CER also plays a significant role in photonics since it contributes to the propagation losses in the performance of a photonic crystal with holes and changes its refractive index. [3][4][5][6][7]14 In previous works of our group, we have developed and presented an advanced measurement and characterization methodology of CER and critical dimension uniformity (CDU), which starts from top-down scanning electron microscope (SEM) images of contact hole patterns and the detection of their edges, and results in the estimation of local and global CDU measures (CD variances) and CER metrics such as root mean square (RMS), correlation length, fractal exponent, power spectrum (PS) and height-height correlation function (HHCF). [3][4][5][6][7]14 In previous works of our group, we have developed and presented an advanced measurement and characterization methodology of CER and critical dimension uniformity (CDU), which starts from top-down scanning electron microscope (SEM) images of contact hole patterns and the detection of their edges, and results in the estimation of local and global CDU measures (CD variances) and CER metrics such as root mean square (RMS), correlation length, fractal exponent, power spectrum (PS) and height-height correlation function (HHCF).…”

Section: Introductionmentioning

confidence: 99%

“…Similar behavior has also been reported in the literature. 14 Initial modeling works focused on the evaluation of photon shot noise (PSN) effects and the critical resist sensitivity below which they can be observed. [3][4][5][6][7] The reported trends are summarized in Table 1.…”

Section: Introductionmentioning

confidence: 99%

Critical dimension uniformity and contact edge roughness in extreme ultraviolet lithography: effect of photoacid generator, sensitizer and quencher

Kuppuswamy

Constantoudis

Gogolides

et al. 2013

J. Micro/Nanolith. MEMS MOEMS

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Downloaded From: http://nanolithography.spiedigitallibrary.org/ on 05/15/2015 Terms of Use: http://spiedl.org/termsCritical dimension uniformity and contact edge roughness in extreme ultraviolet lithography: effect of photoacid generator, sensitizer and quencher Abstract. One of the main challenges for developing extreme ultraviolet resists is to satisfy critical dimension uniformity (CDU) and sidewall roughness of contacts to the allowable limit. To this end, further understanding of the effects of resist ingredients on CDU and contact edge roughness (CER) is required. We investigate the effects of a photoacid generator (PAG), sensitizer and quencher concentrations on the CDU and CER. We find that the dependencies of CDU on sensitizer and quencher are dominated by photon shot noise (PSN) effects whereas a more complicated interplay between PSN and PAG distribution statistics should be considered in the dependence of CDU on PAG concentration. The estimated CER parameters [root mean square (RMS) value and correlation length ξ] exhibit a merging trend when plotted against the final critical dimension (CD). In addition, RMS value increases with exposure dose and PAG loading contrary to shot noise expectations. Power spectrum analysis reveals the dominant contribution of low-frequency undulations to CER, which is attributed to the enhanced interaction along specific directions between the aerial image and/or acid kinetics of nearby contacts. This inter-contact effect is further intensified with CD for fixed pitch and may explain the observed CER behavior.

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Optimization of lithography process to improve image deformation of contact hole sub-90 nm technology node

Cited by 5 publications

References 0 publications

Contact edge roughness (CER) characterization and modeling: effects of dose on CER and critical dimension (CD) variation

Contact edge roughness (CER) characterization and modeling: effects of dose on CER and critical dimension (CD) variation

Contact edge roughness and CD uniformity in EUV: effect of photo acid generator and sensitizer

Critical dimension uniformity and contact edge roughness in extreme ultraviolet lithography: effect of photoacid generator, sensitizer and quencher

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