Detailed resist film modeling in stochastic lithography simulation for line-edge roughness quantification

Patsis, G. P.; Drygiannakis, D.; Raptis, Ioannis

doi:10.1016/j.mee.2009.11.122

Cited by 14 publications

(13 citation statements)

References 9 publications

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“…Second, inclusion of explicit developer solvent molecule will be performed for improving the description of development process from the current dissoluble chain removal method, and several molecular/stochastic simulations − will be a useful guideline for the modeling.…”

Section: Discussion: Pag Loading Effectmentioning

confidence: 99%

Multiscale Simulation Approach on Sub-10 nm Extreme Ultraviolet Photoresist Patterning: Insights from Nanoscale Heterogeneity of Polymer

Kim¹,

Moon²,

Choi³

et al. 2018

Macromolecules

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We developed a multiscale model that integrates density functional theory (DFT), molecular dynamics (MD), and the finite difference method (FDM) to reflect the heterogeneous spatial distribution of the material ingredients on sub-10 nm photoresist (PR) pattern fabrication using extreme ultraviolet lithography (EUVL). It allowed the exploration of phototriggered chemical reactions at the molecular level, including photoacid generator (PAG) dissociation, acid diffusion-coupled deprotection, and solubility switching of individual polymer chains. To quantify the progress of the deprotection, a protection ratio of each pendant group was tracked to distinguish the dissoluble PR chains from the developer as the process time elapsed. Deprotection was shown to preferentially occur in the pendant group adjacent to the acid molecule (<0.74 nm), which determined the chemical gradient and solubility switching trend of the PR chains. Based on the full description of the phototriggered chemical reaction, the morphology of the PR line pattern was predicted after wiping out the dissoluble chains. We particularly examined the PAG loading effect (5.68−30.12 wt %) on the line edge roughness (LER) of the PR pattern and predicted the LER inversion phenomenon at the critical threshold PAG concentration, which qualitatively agreed with the experimental observations. Such a LER trend due to PAG loading was explained by the reciprocal interaction between the homogeneous packing of the acid from the dissoluble PR chains and the acid clustering behavior. The variation of the homogeneity of the deprotection in each pendant group was verified as a function of PAG concentration, which rationalized the existence of the reciprocal interaction.

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Section: Discussion: Pag Loading Effectmentioning

confidence: 99%

Multiscale Simulation Approach on Sub-10 nm Extreme Ultraviolet Photoresist Patterning: Insights from Nanoscale Heterogeneity of Polymer

Kim¹,

Moon²,

Choi³

et al. 2018

Macromolecules

View full text Add to dashboard Cite

show abstract

“…Because of the increasing importance of polymer-size effects at this level, e.g., their impact on LER and line width variation, there is a growing need of photoresist studies based on molecular level models. To improve this, several stochastic approaches have also been proposed in the literature. − These models are more time-consuming, because they consider ensembles of discretely interacting materials. On the other hand, they can quantify realistic material physical and chemical properties such LER.…”

Section: Introductionmentioning

confidence: 99%

Understanding Acid Reaction and Diffusion in Chemically Amplified Photoresists: An Approach at the Molecular Level

Rodríguez-Cantó

Nickel

Abargues³

2011

J. Phys. Chem. C

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Acid diffusion in chemically amplified resist might limit the ultimate minimum half-pitch that can be achieved with high sensitivity resists unless diffusion length is reduced until new methods of sensitizing resists are found. Precise knowledge of molecular dynamics of resist materials and advanced techniques need to be developed actively for this issue. In this sense, computer simulations have become a valuable tool in terms of reducing time and costs. However, simulations are generally based on continuum or mesoscale models, which are unable to accurately predict variations at the molecular level. Deeper understanding and investigation of the coupled reaction-diffusion kinetics at the molecular scale during the postexposure bake (PEB) become crucial to achieve nanoscale features with good critical dimension control and good line-edge roughness. In this work we have developed a molecular level approach for understanding of the coupled acid-catalyzed diffusion process in chemically amplified resist systems. Here, the molecules of photoacid generator are selected as the building blocks of a three-dimensional grid. Reaction and diffusion of the photoconverted acid molecules during the PEB step will produce resist volumes of cleaved polymers. After a certain PEB time τ, these created volumes produced by adjacent acids will almost contact each other, enabling the subsequent development of the polymer. We also determine this parameter τ by means of experiments with real resist systems and investigate the influence of the process conditions on it.

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“…In order to estimate the necessary resist sensitivity and LWR, simulations present a good tool. The quality of such simulations had been shown already for DUV and EUV lithography [8][9][10]. Combining tool parameters with parameters describing the chemical and physical effects, one can carry out a LWR simulation.…”

Section: Line Width Roughnessmentioning

confidence: 99%

Optimization of MSB for future technology nodes

Doering

Elster

Klein

et al. 2012

Alternative Lithographic Technologies IV

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In the ITRS roadmap [1] increasingly long mask write and cycle time is explicitly addressed as a difficult challenge in mask fabrication for the 16nm technology node and beyond. Write time reduction demands have to be seen in relation to corresponding performance parameters like Line Width Roughness (LWR), resolution, placement as well as CD Uniformity.The previously presented Multi Shaped Beam (MSB) approach [2, 3] is considered a potential solution for high throughput mask write application. In order to fully adapt the MSB concept to future industry's requirements specific optimizations are planned.The key element for achieving write time reduction is a higher probe current at the target, which can be obtained by increasing the number of beamlets as well as applying a higher current density. In the present paper the approach of a 256 beamlet MSB design will be discussed. For a given image field size along with a beamlet number increase both beamlet pitch and size have to be optimized. Out of previous investigations, one finding was that by changing the demagnification after the beam forming section of the MSB column the overall performance can be optimized. Based on first electron-optical simulations for a new final lens a larger demagnification turned out to be advantageous. Stochastic beam blur simulation results for the MSB reduction optics will be presented. During the exposure of a pattern layout the number of used beams, their shape and their distribution within the image field varies, which can lead to space charge distortion effects. In regard to this MSB simulation results obtained for an image field of approximately 10x10µm² will be presented. For the 256 beamlet MSB design and resist sensitivities of 20µC/cm², 40µC/cm² and 100µC/cm² write time and LWR simulations have been performed. For MSB pattern data fracturing an optimized algorithm has been used, which increased the beamlet utilization factor (indicates the mean number of beamlets which are used per multi-shot). Finally an update with regard to the required changes of the data path architecture for the 256 beamlet MSB approach will be given. Data integrity as an important aspect of the production worthiness of such a systems will be discussed specifically.

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Detailed resist film modeling in stochastic lithography simulation for line-edge roughness quantification

Cited by 14 publications

References 9 publications

Multiscale Simulation Approach on Sub-10 nm Extreme Ultraviolet Photoresist Patterning: Insights from Nanoscale Heterogeneity of Polymer

Multiscale Simulation Approach on Sub-10 nm Extreme Ultraviolet Photoresist Patterning: Insights from Nanoscale Heterogeneity of Polymer

Understanding Acid Reaction and Diffusion in Chemically Amplified Photoresists: An Approach at the Molecular Level

Optimization of MSB for future technology nodes

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