Zernike sensitivity method for CD distribution

Nakashima, Toshiharu; Slonaker, Steve D.; Kudo, Takehito; Hirukawa, Shigeru

doi:10.1117/12.485454

Cited by 9 publications

(5 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…where k = 2π/λ is the wave number, λ is the wavelength of the monochromatic light source, and W(f, g, h) is the total aberrated wavefront including the lens aberration W lens (f, g) that is commonly classified into an odd aberration W odd (f, g) and an even aberration W even (f, g), and another even-type aberration W defocus (f, g, h) that is induced by and proportional to the axial shift h of the aerial image sensor [21]:…”

Section: Aerial Image Spectrum Analysismentioning

confidence: 99%

Aerial image based technique for measurement of lens aberrations up to 37th Zernike coefficient in lithographic tools under partial coherent illumination

Liu¹,

Liu²,

Zhou³

et al. 2009

Opt. Express

View full text Add to dashboard Cite

This paper proposes a technique for in situ measurement of lens aberrations up to the 37th Zernike coefficient in lithographic tools under partial coherent illumination. The technique requires the acquisition and analysis of aerial image intensities of a set of 36 binary gratings with different pitches and orientations. By simplifying the theoretical derivation of the optical imaging under partial coherent illumination, two linear models are proposed in a compact expression with two matrixes, which can be easily obtained in advance by numerical calculation instead of by lithographic simulators, and then used to determine the Zernike coefficients of odd aberration and even aberration respectively. The simulation work conducted by PROLITH has validated the theoretical derivation and confirms that such a technique yields a superior quality of wavefront estimate with an accuracy of Zernike coefficients on the order of 0.1 m lambdas (lambda = 193 nm) and an accuracy of wavefronts on the order of m lambdas, due to further considering the influence of the partial coherence factor on pupil sampling. It is fully expected that this technique will simple to implement and will provide a useful practical means for the in-line monitoring of imaging quality of lithographic tools under partial coherent illumination.

show abstract

Section: Aerial Image Spectrum Analysismentioning

confidence: 99%

Aerial image based technique for measurement of lens aberrations up to 37th Zernike coefficient in lithographic tools under partial coherent illumination

Liu¹,

Liu²,

Zhou³

et al. 2009

Opt. Express

View full text Add to dashboard Cite

show abstract

“…[2][3][4] As a result, we obtain knowledge that the CD error caused by a mask 3-D effect is similar to that caused by the influence of aberrations.…”

Section: Introductionmentioning

confidence: 79%

Design for manufacture to deal with mask-induced critical dimension errors in the extreme ultraviolet

Nakajima

Satō

Inanami

et al. 2010

J. Micro/Nanolith. MEMS MOEMS

View full text Add to dashboard Cite

The actual extreme ultraviolet lithography tools will have aberrations around seven times larger than those of the latest ArF lithography tools in wavelength normalized rms. We calculated the influence of aberrations on the size error and pattern shift error using Zernike sensitivity analysis. Mask-induced aberration restricts the specification of aberration. Without periodic additional pattern, the aberration level that can be accepted to form 22 nm dual-gate patterns was Ͻ8 m rms. Arranging the periodic additional pattern relaxed the aberration tolerance. With periodic additional pattern, the acceptable aberration level to form 22 nm patterns was below Ͻ37 m rms. It is important to make pattern periodicity for the relaxation of the aberration specification.

show abstract

“…Based on such good imaging field prediction, we can move one step further to predict through focus CD behavior by summing up the products of Zernike sensitivity, Zernike coefficients and their cross talk terms [4]. It enables a quick printing performance prediction of ACLV and DOF for lens optimization based on Zernike sensitivity and lens …”

Section: Correlation Between Scatterlith Asml Focal and Lithographymentioning

confidence: 99%

“…Recently many studies have been conducted to understand the potential root causes of ACLV. In summary, the root causes of ACLV can be classified in the following categories: 1) Projection lens aberrations, their cross talk effects and flare [1][2][3][4][5][6]: Although advanced scanner lens aberration control has reached an unprecedented level, the aberration sensitivity of printed patterns increases with shrinking feature size, tightened CD error tolerance and application of complicated resolution enhancement techniques;…”

Section: Introductionmentioning

confidence: 99%

Characterization of ACLV for advanced technology nodes using scatterometer-based lens fingerprinting technique

et al. 2004

View full text Add to dashboard Cite

Gate CD control is crucial to transistor fabrication for advanced technology nodes at and beyond 65 nm. ACLV (across chip linewidth variation) has been identified as a major contributor to overall CD budget for low k 1 lithography. In this paper, we present a detailed characterization of ACLV performance on the latest ASML scanner using Texas Instruments proprietary scatterometer based lens fingerprinting technique (ScatterLith). We are able to decompose a complex ACLV signature including patterns placed in both vertical and horizontal directions and trace the CD errors back to various scanner components such as lens aberrations, illumination source shape, dynamic image field, and scan synchronization. Lithography simulation plays an important role in bringing together the wafer and tool metrology for direct correlation and providing a quantitative understanding of pattern sensitivity to lens and illuminator errors for a particular process setup. A new ACLV characterization methodology is enabled by combining wafer metrology ScattereLith, scanner metrology and lithography simulation. Implementation of this methodology improves tool-to-tool matching and control on ACLV and V-H bias across multiple scanners to meet tight yield and speed requirements for advanced chip manufacturing.

show abstract

Zernike sensitivity method for CD distribution

Cited by 9 publications

References 0 publications

Aerial image based technique for measurement of lens aberrations up to 37th Zernike coefficient in lithographic tools under partial coherent illumination

Aerial image based technique for measurement of lens aberrations up to 37th Zernike coefficient in lithographic tools under partial coherent illumination

Design for manufacture to deal with mask-induced critical dimension errors in the extreme ultraviolet

Characterization of ACLV for advanced technology nodes using scatterometer-based lens fingerprinting technique

Contact Info

Product

Resources

About