Progress on implementation of a CD-AFM-based reference measurement system

Orji, Ndubuisi G.; Martinez, Angela; Dixson, Ronald G.; Allgair, John A.

doi:10.1117/12.653287

Cited by 17 publications

(17 citation statements)

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“…This particular CD-AFM, which is implemented as a reference measurement system (RMS), has been previously used as a reference instrument for linewidths [10]. We now extend the RMS capability of this instrument to sidewall angle measurement.…”

Section: Reference Measurementsmentioning

confidence: 98%

“…However, the TMU achieved (1.164º) is less than the estimated uncertainty in the XSEM SWA determination, i.e., the fit is as good as the reference metrology allows. More exacting correlations were done between CD-SEM and the SEMATECH/NIST RMS CD-AFM [10]. Navigation on the sample was matched between the recipes on the different tools to ensure that the same 2 µm long line segments were measured on each tool, thus making possible a "direct correlation" between the tools.…”

Section: Experiments 1: Sub-100 Nm Photoresist Lines Of 290 Nm Heightmentioning

confidence: 99%

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The coming of age of tilt CD-SEM

Bunday¹,

Allgair²,

Solecky³

et al. 2007

SPIE Proceedings

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The need for 3D metrology is becoming more urgent to address critical gaps in metrology for both lithographic and etch processes. Current generation lithographic processing (ArF source, where λ=193 nm) sometimes results in photoresist lines with re-entrant profiles or T-topping, as do many etch processes. A re-entrant profile misleads top-down metrology into reading the critical dimension (CD) as too large. Recent advances in gate process technology also raise challenges to traditional top-down metrology. One such example is the FinFET, which is truly a 3D device with 3D metrology needs.The ability to measure the bottom width of a profile is crucial for process control. Recently, tilt-beam critical dimensionscanning electron microscopy (CD-SEM) applications have been developed to measure the bottom CD of such features, using the tilted-view to "see" the bottom, avoiding the feature's larger top. This is an important achievement, as the bottom of a profile is the main feature of interest in many processes.Estimation of sidewall angle (SWA) is also important. For several years, tilt-beam CD-SEM has been an available technique for this measurement, with limited adoption by the litho-metrology community. However, in this paper we will explore another method to use the tilt feature to measure average sidewall angle, based on edgewidth measurement and the assumption of basic trapezoidal profile and known height and combined with the ability to sample multiplefeatures. While it will not provide exact profile shape, this technique can be quite useful in providing average profile information and will definitely exhibit good throughput. Samples used will be photoresist and etched FinFET structures to measure sidewall angles. Correlations of the results to a traceable CD-atomic force microscopy (AFM) reference measurement system are provided.. Conclusions will show preliminary findings of the readiness of tilt-beam CD-SEM for measuring profile and, by extension, the status of measuring 3D structures such as FinFETs, and using CD-SEM as a direct control of lithographic tooling for T-topped photoresist profiles.

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Section: Reference Measurementsmentioning

confidence: 98%

Section: Experiments 1: Sub-100 Nm Photoresist Lines Of 290 Nm Heightmentioning

confidence: 99%

The coming of age of tilt CD-SEM

Bunday¹,

Allgair²,

Solecky³

et al. 2007

SPIE Proceedings

View full text Add to dashboard Cite

show abstract

“…This is very important for controlling final gate CD distributions. Since the CD-SEM can be calibrated to a highly accurate reference measurement system like a CD-AFM [8] and the tool can be used in-circuit to verify the likeness of similar features, good control is possible. Metrology executed in this way is at the heart of the current movement towards "design for manufacturability" (DFM).…”

Section: Importance Of Metrologymentioning

confidence: 99%

The ROI of Metrology

Bunday¹,

Allgair

Caldwell³

et al. 2006

2006 IEEE International Symposium on Semiconductor Manufacturing

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The conventional premise that metrology is a is the result of the metrology team executing its job correctly "non-value-added necessary evil" is a misleading one, which and thoroughly. mufst he viewed as obsolete thinking. Much oJf the metrololQv requirements are now key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts ofthe processes. This paper will explore the present and future trends and challenges in CD metrology. However, equipment is only part of the battle. The quality application of these tools in a production environment is quite important; the ultimate valueadded by metrology is a result ofquality tools run by a quality metrology team using quality practices.

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“…This is important for controlling final gate CD distributions. Since the CD-SEM can be calibrated to a highly accurate reference measurement system like a CD-atomic force microscope (AFM) [8] and the tool can be used in-circuit to verify the likeness of similar features, good control is possible. Metrology executed in this way is at the heart of the current movement towards design for manufacturability (DFM).…”

Section: Status Of CD Metrology Toolingmentioning

confidence: 99%

Value-Added Metrology

Bunday¹,

Allgair²,

Caldwell³

et al. 2007

IEEE Trans. Semicond. Manufact.

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The conventional premise, long-touted among the semiconductor processing community, that metrology is a "non-value-added necessary evil," is a misleading and dangerous assertion, which must be viewed as obsolete thinking. Many metrology applications are key enablers to traditionally labeled "value-added" processing steps in lithography and etch, such that they can be considered integral parts of the processes.Various key trends in modern, state-of-the-art processing such as optical proximity correction, design for manufacturability, and advanced process control are based, at their hearts, on the assumption of fine-tuned metrology, in terms of uncertainty and accuracy. These trends are vehicles where metrology thus has large opportunities to create value through the engineering of tight and targetable process distributions. Such distributions make possible predictability in speed-sorts and in other parameters, which results in a high-end product. Additionally, significant reliance has also been placed on defect metrology to predict, improve, and reduce yield variability. The necessary quality metrology is strongly influenced by not only the choice of equipment, but also the quality application of these tools in a production environment. The ultimate value added by metrology is a result of quality tools run by a quality metrology team using quality practices. This paper will explore the relationships among present and future trends and challenges in metrology, including equipment, key applications, and metrology deployment in the manufacturing flow. Of key importance are metrology personnel, with their expertise, practices, and metrics in achieving and maintaining the required level of metrology performance, including where precision, matching, and accuracy fit into these considerations. The value of metrology will be demonstrated to have shifted to being a "key enabler of large revenues," debunking the out-of-date premise that metrology is "non-value-added." Index Terms-Advanced process control (APC), critical dimension (CD), design-based metrology (DBM), design for manufacturability (DFM), ISMI, metrology, optical proximity correction (OPC).

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Progress on implementation of a CD-AFM-based reference measurement system

Cited by 17 publications

References 0 publications

The coming of age of tilt CD-SEM

The coming of age of tilt CD-SEM

The ROI of Metrology

Value-Added Metrology

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