Fast and accurate 3D mask model for full-chip OPC and verification

Liu, Peng; Cao, Yu; Chen, Luoqi; Chen, Guangqing; Mu, Feng; Jiang, Jiong; Liu, Huayu; Suh, Sungsoo; Lee, Sung‐Woo; Lee, Suk-Joo

doi:10.1117/12.712171

Cited by 41 publications

(19 citation statements)

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“…Clearly, there is little question that with the more physical 3D mask model, we can achieve smaller model calibration errors through pitch in both focus settings. [7] Figure 9. 3D mask model improves model fitting and prediction errors for 45nm CD through-pitch for best and defocus setting of -60nm.…”

Section: Effect Of 3d Mask Versus Thin Mask Modelmentioning

confidence: 98%

Separable OPC models for computational lithography

Liu¹,

Zhao²,

Chen³

et al. 2008

SPIE Proceedings

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The challenge for the upcoming full-chip CD uniformity (CDU) control at 32nm and 22nm nodes is unprecedented with expected specifications never before attempted in semiconductor manufacturing. To achieve these requirements, OPC models not only must be accurate for full-chip process window characterization for fine-tuning and matching of the existing processes and exposure tools, but also be trust-worthy and predictive to enable processes to be developed in advance of next-generation photomasks, exposure tools, and resists. This new OPC requirement extends beyond the intended application scope for behavior-lumped models. Instead, separable OPC models are better suited, such that each model stage represents the physics and chemistry more completely in order to maintain reliable prediction accuracy. The resist, imaging tool, and mask models must each stand independently, allowing existing resist and mask models to be combined with new optics models based on exposure settings other than the one calibrated previously.In this paper, we assess multiple sets of experimental data that demonstrate the ability of the Tachyon™ FEM (focus and exposure modeling) to separate the modeling of mask, optics, and resists. We examine the predictability improvements of using 3D mask models to replace thin mask model and the use of measured illumination source versus top-hat types. Our experimental wafer printing results show that OPC models calibrated in FEM to one optical setting can be extrapolated to different optical settings, with prediction accuracy commensurate with the calibration accuracy. We see up to 45% improvement with the measured illumination source, and up to 30% improvement with 3D mask. Additionally, we observe evidence of thin mask resist models that are compensating for 3D mask effect in our wafer data by as much as 60%.

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Section: Effect Of 3d Mask Versus Thin Mask Modelmentioning

confidence: 98%

Separable OPC models for computational lithography

Liu¹,

Zhao²,

Chen³

et al. 2008

SPIE Proceedings

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“…A set of W3D+ filters are extracted from the library and used for rendering full-chip wafer topography effects. This approach is similar to ASML Brion's Mask 3D solution [1,2]. The dominant scattering effects from underlying pattern edges are captured by these W3D+ filters.…”

Section: Introductionmentioning

confidence: 98%

“…The dominant scattering effects from underlying pattern edges are captured by these W3D+ filters. Additionally, the residual scattering effect is allowed to be modeled by using terms from a kernel based empirical model [2]. Based on the implementation, this W3D+ model is more physical, accurate and predictive.…”

Section: Introductionmentioning

confidence: 99%

Wafer sub-layer impact in OPC/ORC models for advanced node implant layers

et al. 2014

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From 28 nm technology node and below optical proximity correction (OPC) needs to take into account light scattering effects from prior layers when bottom anti-reflective coating (BARC) is not used, which is typical for ionic implantation layers. These effects are complex, especially when multiple sub layers have to be considered: for instance active and poly structures need to be accounted for.A new model form has been developed to address this wafer topography during model calibration called the wafer 3D+ or W3D+ model. This model can then be used in verification (using Tachyon LMC) and during model based OPC to increase the accuracy of mask correction and verification. This paper discusses an exploration of this new model results using extended wafer measurements (including SEM). Current results show good accuracy on various representative structures.

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“…Possible contributions come from the resist model, proximity effects from metrology, uncertainties from the scanner optics such as lens apodization and lens polarization. Finally the mask characterization and the modeling of mask diffraction is eventually another important factor to OPC accuracy [15,17].…”

Section: Introductionmentioning

confidence: 99%

Rigorous simulation study of mask gratings at conical illumination

Köhle¹

2007

SPIE Proceedings

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For immersion technology the mask is illuminated under large angles and the features sizes are approaching the illuminating wavelength. At such operating conditions, several publications have shown rigorous diffraction effects having a noticeable effect on the aerial image. For the Kirchhoff assumption, which is commonly employed in lithography simulation, the mask is assumed to be an infinity thin transparency. This assumption implies the diffracted spectrum to be independent of the incident illumination angle and no coupling between polarization states occurs. This work is a fundamental study to deepen the understanding of rigorous off-axis effects for current and future mask technologies. This paper will show simulation studies for standard attenuated-and alternating mask gratings, which look at the diffracted spectrum of a mask grating with respect to polarization orientation and off-axis angle of the illuminating wave.

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Fast and accurate 3D mask model for full-chip OPC and verification

Cited by 41 publications

References 0 publications

Separable OPC models for computational lithography

Separable OPC models for computational lithography

Wafer sub-layer impact in OPC/ORC models for advanced node implant layers

Rigorous simulation study of mask gratings at conical illumination

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