Mask induced polarization effects at high NA

Estroff, Andrew; Fan, Yongfa; Bourov, Anatoly; Smith, Bruce W.; Foubert, Philippe; Leunissen, L. H. A.; Philipsen, Vicky; Aksenov, Y.

doi:10.1117/12.602422

Cited by 10 publications

(2 citation statements)

References 8 publications

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“…1). The absorption of TE and TM mode differs depending on the binary to attenuated mask types, and its effect may be beneficial to induce an added mask induced polarization effect [7][8][9][10]. The effect may be considered as increase in degree of polarization.…”

Section: Introductionmentioning

confidence: 97%

Three-dimensional mask effect approximate modeling for sub-50-nm node device OPC

et al. 2007

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In order to perform an optical proximity correction of memory device nodes below half-pitch 50nm, so called 3D mask effects need to be included in a model based OPC. As the mask pitch approaches wavelength of an optical system, and the angle of off-axis illumination becomes increasingly greater than normal incident beam, combined effects of transmission loss and mask induced polarization induces deviations from Kirchhoff thin mask approximation. Presently, just a handful of methods are being developed for commercial use in full-chip scale optical proximity correction: edge domain decomposition method (DDM), rim-type boundary layer and more recently, M3D model [1-6]. However, these methods currently require extensive modeling and proximity correction runtime although its methods are being continously improved for accuracy and speed. In this work, some results on an alternative approach to 3D mask modeling that is suitable for OPC are presented. Using modeling test pattern experimental data and FDTD rigorous simulation results, a thin mask approximation and alternative 3D mask approximate approaches are compared. And the results indicate improved model accuracy in terms of root mean square of 30% for a cross-pole and a dipole illumination conditions, respectively, while the OPC run-time remained similar. Furthermore, a flash memory gate-poly OPC results using the 3D mask approximate model indicates improved correlation to experimental results than a thin mask model at minimum resolution dense feature and narrow space regions.Thin mask and proposed approximate 3D mask models were calibrated for three differing illumination conditions: two X-dipole illuminations with Y-linear polarization and cross-pole quasar illumination with X&Y-linear polarization states. For each of the extreme off-axis illumination conditions, 3D mask approximate model developed for OPC indicated improved calibration results to both test pattern wafer images and rigorous simulation results. In addition, OPC layout image contours of 3D mask approximate model correlated better to wafer image than the thin mask approximation at nominal and defocus conditions.

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Section: Introductionmentioning

confidence: 97%

Three-dimensional mask effect approximate modeling for sub-50-nm node device OPC

et al. 2007

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“…The NA of the exposure tool can be increased further using a highrefractive-index liquid. This immersion exposure tool introduces the hyper NA regime in which polarization 2) and the three-dimensional mask topography effect 3) appear to have significant effects on imaging results. The analysis to comprehend hyper NA imaging results requires complicated and rigorous approaches, which makes it difficult to understand the imaging mechanism through insight.…”

Section: Introductionmentioning

confidence: 99%

Study of Mask Proximity Impact on Mask Mean-to-Target Specification

Lee

Choi

et al. 2007

jjap

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An analytic relationship of the mask mean-to-target (MTT) and the mask uniformity specifications affected by the mask proximity effect (MPE) is suggested. MPE mainly caused by e-beam proximity and the etch loading effect makes different MTTs for patterns with different pitch sizes. À is the parameter introduced to represent MTT differences induced by MPE. The mask MTT and uniformity (M-U) curves which define the boundary of the specification region shift along the mask MTT axis according to the sign of À . The mask M-U curves translate upward for a positive À and downward for a negative À . M-U specifications are calculated for 45 and 51 nm half-pitch sizes. À 's are obtained from the experimental proximity curve and they are À0:5 and À0:8 nm for the 45 and 51 nm nodes, respectively. For the 45 nm node, the lower and upper mask MTT specifications are À5:35 and 3.91 nm, respectively. For the 51 nm node, the lower and upper MTT specifications are À9:00 and 3.90 nm, respectively. M-U curves are shown to be translated downward for negative À 's and their amounts are À2:55 and À0:72 nm for the 45 and 51 nm nodes, respectively.

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