Holistic approach using accuracy of diffraction-based integrated metrology to improve on-product performance, reduce cycle time, and cost at litho

Bhattacharyya, Kaustuve; Boef, Arie den; Jak, Martin; Zhang, Gary; Maassen, Martijn; Tijssen, Robin; Adam, Omer; Fuchs, Andreas; Zhang, Youping; Huang, Jacky; Couraudon, Vincent; Tzeng, Wilson; Su, Eason; Wang, Cathy; Kavanagh, Jim; Fouquet, Christophe

doi:10.1117/12.2085678

Cited by 10 publications

(7 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here comes a need to systematically choose the appropriate sub-segmentation mark types, determine the optimal signal intensity, select the marks that are most robust to asymmetry, and calculate the optimal wavelength scheme. Driven by such requirements, an integrated simulation software D4C (design for control) is applied to design and optimize the alignment marks [41][42][43] , making it more efficient and low-cost to design the marks.…”

Section: Development Of Alignment Marks and Efficient Methods For Mar...mentioning

confidence: 99%

Review of overlay error and controlling methods in alignment system for advanced lithography

Hao¹,

Qi²

2022

Thirteenth International Conference on Information Optics and Photonics (CIOP 2022)

View full text Add to dashboard Cite

Acting as one of the three critical indicators to evaluate the performance of lithography scanners, overlay has been a vital factor which seriously affects the electric property, life span and reliability of integrated circuits (IC). With continuous developments of technology nodes and applications of resolution enhancement technologies (RET), current resolution of the scanners has shrunk to 7 nm and beyond, proposing more stringent requirements for measuring, monitoring and correcting the overlay error. To ensure that the overlay budget fully met by the scanner, advanced optical technologies and holistic alignment approaches have been gradually applied to the alignment system of the scanner, revealing that an integrated methodology in which multiple technologies are adopted proved to be valid and effective in reducing the overlay error in present technology nodes.In this article, the exact concept of overlay error is provided, and on this basis different methods to describe the overlay error are comprehensively analyzed from the perspectives of classifications, sources, quality control and correcting models. Then the systematic relationship between alignment and overlay is illustrated. Recent improvements in the alignment system are also the key points here to systematically reduce the overlay error, including the optimization of the alignment optical path, mark types and design procedures, as well as the application of optimal color weighting (OCW), wafer alignment model mapping (WAMM) and sampling scheme optimization (SSO) algorithms. Based on the combined application and iteration of these technologies, it is believed that the on-product overlay (OPO) can be further compressed to support the continuous tightening of the overlay budget in the industry of IC.

show abstract

Section: Development Of Alignment Marks and Efficient Methods For Mar...mentioning

confidence: 99%

Review of overlay error and controlling methods in alignment system for advanced lithography

Hao¹,

Qi²

2022

Thirteenth International Conference on Information Optics and Photonics (CIOP 2022)

View full text Add to dashboard Cite

show abstract

“…TMU is a figure of merit with various definitions. For OV metrology we use the following definition for TMU [36]:…”

Section: Overlay Metrologymentioning

confidence: 99%

“…First of all, in our definition the average TIS contribution across the wafer is included since this term is normally not corrected for by an extra 180°w afer rotation. Secondly, the term that represents the matching between metrology tools is not included since this is reported as a separate number as presented in [36].…”

Section: Overlay Metrologymentioning

confidence: 99%

Optical wafer metrology sensors for process-robust CD and overlay control in semiconductor device manufacturing

Boef

2016

Surf. Topogr.: Metrol. Prop.

View full text Add to dashboard Cite

This paper presents three optical wafer metrology sensors that are used in lithography for robustly measuring the shape and position of wafers and device patterns on these wafers. The first two sensors are a level sensor and an alignment sensor that measure, respectively, a wafer height map and a wafer position before a new pattern is printed on the wafer. The third sensor is an optical scatterometer that measures critical dimension-variations and overlay after the resist has been exposed and developed. These sensors have different optical concepts but they share the same challenge that sub-nm precision is required at high throughput on a large variety of processed wafers and in the presence of unknown wafer processing variations. It is the purpose of this paper to explain these challenges in more detail and give an overview of the various solutions that have been introduced over the years to come to process-robust optical wafer metrology.

show abstract

“…al. [4]) for the need of overlay measurements not just between two layers, but between multiple layers enabling accurate process optimization for complex circuit designs continues into the 10nm and 7nm workflows. For some layers, a simple 2 layer registration is no longer sufficient, and 3 or more layers need to be taken into account.…”

Section: Introductionmentioning

confidence: 99%

New approaches in diffraction based optical metrology

et al. 2016

View full text Add to dashboard Cite

Requirements for on-product overlay, focus and CD uniformity continue to tighten in order to support the demands of 10nm and 7nm nodes. This results in the need for simultaneously accurate, robust and dense metrology data as input for closed-loop control solutions thereby enabling wafer-level control and high order corrections. In addition the use of opaque materials and stringent design rules drive the need for expansion of the available measurement wavelengths and metrology target design space.Diffraction based optical metrology has been established as the leading methodology for integrated as well as standalone optical metrology for overlay, focus and CD monitoring and control in state of the art chip manufacturing. We are presenting the new approaches to diffraction based optical metrology designed to meet the ≤10nm node challenges. These approaches have been implemented in the latest addition to the YieldStar metrology platform, the YS350E introducing a new way of acquiring and processing diffraction based metrology signals.In this paper we will present the new detection principle and its impact on key performance characteristics of overlay and focus measurements. We will also describe the wide range of applications of a newly introduced increased measurement spot size, enabling significant improvements to accuracy and process robustness of overlay and focus measurements.With the YS350E the optical CD measurement capability is also extended, to 10x10µm 2 targets. We will discuss the performance and value of small targets in after-develop and after-etch applications.

show abstract

Holistic approach using accuracy of diffraction-based integrated metrology to improve on-product performance, reduce cycle time, and cost at litho

Cited by 10 publications

References 5 publications

Review of overlay error and controlling methods in alignment system for advanced lithography

Review of overlay error and controlling methods in alignment system for advanced lithography

Optical wafer metrology sensors for process-robust CD and overlay control in semiconductor device manufacturing

New approaches in diffraction based optical metrology

Contact Info

Product

Resources

About