Metrology of deep trench etched memory structures using 3D scatterometry

Reinig, Peter; Dost, R.; Moert, Manfred; Hingst, Thomas; Mantz, U.; Moffitt, Jasen; Shakya, Sushil; Raymond, Christopher J.; Littau, Mike

doi:10.1117/12.599342

Cited by 8 publications

(4 citation statements)

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“…As a metrology technique widely used in semiconductor industry, scatterometry has been applied to a variety of measuring objectives: line cross-sectional profile (such as critical dimension, sidewall angle) metrology [1] , overlay metrology [2] , line edge roughness metrology [3] , 2D/3D grating metrology [4,5] , etc. For each objective, there is a specialized scatterometry method with high sensitivity for the specific grating structure.…”

Section: Introductionmentioning

confidence: 99%

Specialized scatterometry methods for two types of gratings with distinct groove profiles

Lin¹

2015

SPIE Proceedings

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This paper focuses on specialized scatterometry methods for two types of featured grating structures: highly asymmetric triangular grating on a transparent substrate (type I), and standing-wave photoresist mask grating on a reflective substrate (type II). Compared with the conventional microstructures occurring in semiconductor metrology, both type I and type II have distinct groove profiles, which makes their specialized scatterometry methods also different from the conventional ones. Combining with two specific cases, by using the asymmetry of triangular profile in type I grating, and the strong dispersion property of the specific substrate in type II grating, the paper shows the feasibility of specialized scatterometry methods with high profile reconstruction sensitivity.

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Section: Introductionmentioning

confidence: 99%

Specialized scatterometry methods for two types of gratings with distinct groove profiles

Lin¹

2015

SPIE Proceedings

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“…It is well recognized that the success of MBIR metrology relies heavily on accurate forward modeling and fast calculation of the infrared metrology process, which still remains a challenge, especially for 3D deep-trench structures. Rigorous coupled wave analysis (RCWA) [4][5][6] is ideally suited to simulate the optical response of periodic surface-relief structures and has been commonly used for modeling in scatterometry [7][8][9]. RCWA can achieve optical responses with very high accuracy, but its calculation is quite time consuming.…”

Section: Introductionmentioning

confidence: 99%

Fitting-determined formulation of effective medium approximation for 3D trench structures in model-based infrared reflectrometry

et al. 2011

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The success of the model-based infrared reflectrometry (MBIR) technique relies heavily on accurate modeling and fast calculation of the infrared metrology process, which continues to be a challenge, especially for three-dimensional (3D) trench structures. In this paper, we present a simplified formulation for effective medium approximation (EMA), determined by a fitting-based method for the modeling of 3D trench structures. Intensive investigations have been performed with an emphasis on the generality of the fitting-determined (FD)-EMA formulation in terms of trench depth, trench pitch, and incidence angle so that its application is not limited to a particular configuration. Simulations conducted on a taper trench structure have further verified the proposed FD-EMA and demonstrated that the MBIR metrology with the FD-EMA-based model achieves an accuracy one order higher than that of the conventional zeroth-order EMA-based model.

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“…In the recent time, application of scatterometry to 2D periodic structures has been widely investigated. [11,12,13,14] In this field the technique is still facing serious problems such as enormous computation times and insufficient modehng facilities. The authors of this work presented investigations on 3D scatterometry [15,16] as well as first investigations on rough sidewalk [17] in the recent time.…”

Section: Introductionmentioning

confidence: 99%

Simulations of Scatterometry Down to 22 nm Structure Sizes and Beyond with Special Emphasis on LER

Paz¹,

Frenner²,

Schuster³

et al. 2009

AIP Conference Proceedings

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Abstract. In recent years, scatterometry has become one of the most commonly used methods for CD metrology. With decreasmg structure size for future technology nodes, the search for optimized scatterometry measurement configurations gets more important to exploit maximum sensitivity. As widespread industrial scatterometry tools mainly still use a pre-set measurement configuration, there are still free parameters to improve sensitivity. Our current work uses a simulation based approach to predict and optimize sensitivity of future technology nodes. Since line edge roughness is getting important for such small structures, these imperfections of the periodic continuation cannot be neglected. Using fourier methods like e.g. rigorous coupled wave approach (RCWA) for diffraction calculus, nonperiodic features are hard to reach. We show that in this field certain types of fieldstitching methods show nice numerical behaviour and lead to useful results.

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Metrology of deep trench etched memory structures using 3D scatterometry

Cited by 8 publications

References 0 publications

Specialized scatterometry methods for two types of gratings with distinct groove profiles

Specialized scatterometry methods for two types of gratings with distinct groove profiles

Fitting-determined formulation of effective medium approximation for 3D trench structures in model-based infrared reflectrometry

Simulations of Scatterometry Down to 22 nm Structure Sizes and Beyond with Special Emphasis on LER

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