Phase retrieval of the full vectorial field applied to coherent Fourier scatterometry

Xu, Xiaolong; Konijnenberg, A. P.; Pereira, Silvania F.; Urbach, H. P.

doi:10.1364/oe.25.029574

Cited by 5 publications

(3 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Despite the decrease in parametric correlations, subsequent analysis using the covariance method (as described in section 2.7) reveals that the measurement uncertainties of non-integral measurements are generally higher than integral measurements, as illustrated in figure 22. This issue is not unexpected as non-integral measurements may be more susceptible to local effects, such as line edge roughness (LER) [26], lens aberrations [29], and light spot position [30]. We believe that constructing a more robust model for non-integral measurements by considering these factors can help lower the measurement uncertainties.…”

Section: Comparison Between Integral and Non-integral Measurementsmentioning

confidence: 99%

Non-integral model-based scatterometry for CD metrology of single high-aspect-ratio microstructures

Chein¹,

Yang²,

Fu³

et al. 2023

Surf. Topogr.: Metrol. Prop.

View full text Add to dashboard Cite

This article presents an innovative model-based scatterometry method for CD metrology of single high-aspect-ratio (HAR) microstructures, which are increasingly utilized in advanced packaging, especially as vertical interconnects in three-dimensional integrated circuits. The rapidly growing aspect ratio of these HAR structures makes it challenging to monitor their critical dimensions (CD). Furthermore, conventional spectral reflectometry or scatterometry measurements on periodic metrology targets on the scribe lines of the wafer are inadequate in providing a reliable correlation with the in-die structures due to the integral nature of these measurements, which can result in additional measurement errors compared to measuring individual in-die structures. To address these challenges, we propose a novel scatterometry system that can achieve high-precision single-structure measurement of fine-pitch HAR structures with significantly improved light efficiency over conventional optical methods. Our system takes advantage of the high spatial coherence of the supercontinuum laser source and an optical NA-controlled design concept for precise light beam shaping, enabling high spatial resolution and superior light efficiency in measurements. Furthermore, we demonstrate a model-based measurement scheme that uses a virtual optical system for complete characterization of the sample profile. The experimental results show that the proposed system can accurately measure RDL structures with fine nominal spacing as small as 1 μm and an aspect ratio of 3:1 with high fidelity.

show abstract

Section: Comparison Between Integral and Non-integral Measurementsmentioning

confidence: 99%

Non-integral model-based scatterometry for CD metrology of single high-aspect-ratio microstructures

Chein¹,

Yang²,

Fu³

et al. 2023

Surf. Topogr.: Metrol. Prop.

View full text Add to dashboard Cite

show abstract

“…In this way, all relevant combinations of input-output polarizations can be obtained: TE-TE, TE-TM, TM-TM, and TM-TE. With the addition of one lens, one can obtain the phase distribution of the far field using phase retrieval techniques [16]. grating parameters.…”

Section: Coherent Fourier Scatterometry and The Experimental Setupmentioning

confidence: 99%

Far-field sectioning for the retrieval of subwavelength grating parameters using coherent Fourier scatterometry

Šiaudinytė

Pereira

2020

Meas. Sci. Technol.

View full text Add to dashboard Cite

Optical inspection of periodic nanostructures is a major challenge in the semiconductor industry due to constantly decreasing critical dimensions. In this paper we combine coherent Fourier scatterometry (CFS) with a sectioning mask for subwavelength grating parameter determination. By selecting only the most sensitive regions of the scattered light in the Fourier plane, one can retrieve grating parameters faster and with higher sensitivity than previous approaches. Moreover, the full process of CFS using focused light is explained and implemented in a subwavelength grating regime. The results of using transverse magnetic polarized input fields together with the proposed sectioning mask are presented and compared to the non-mask case.

show abstract

“…To overcome this problem, we increased the dynamic range using the method as explained in the Ref. [18]. For each mask position, several intensity patterns for different exposure times were acquired.…”

Section: Dynamic Rangementioning

confidence: 99%

Phase retrieval applied to coherent Fourier scatterometry using the extended ptychographic iterative engine

Dwivedi¹,

Sakamoto²,

Pereira³

2019

OSA Continuum

Self Cite

View full text Add to dashboard Cite

We have demonstrated that the extended ptychographic iterative engine (ePIE) algorithm can be applied to retrieve the phase information of the vectorial scattered field of a subwavelength object with the amplitude of the scattered field as input. We applied this technique combined with coherent Fourier scatterometry to determine the phase of the scattered field of a subwavelength grating, illuminated by a focused laser beam.

show abstract

Phase retrieval of the full vectorial field applied to coherent Fourier scatterometry

Cited by 5 publications

References 21 publications

Non-integral model-based scatterometry for CD metrology of single high-aspect-ratio microstructures

Non-integral model-based scatterometry for CD metrology of single high-aspect-ratio microstructures

Far-field sectioning for the retrieval of subwavelength grating parameters using coherent Fourier scatterometry

Phase retrieval applied to coherent Fourier scatterometry using the extended ptychographic iterative engine

Contact Info

Product

Resources

About