A Double Pass Attachment For The Linear And Plane Mirror Interferometer

Baldwin, R.; Siddall, G.J.

doi:10.1117/12.943051

Cited by 5 publications

(2 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The stage motion is tracked by optical laser interferometry. The interferometers for both the X and Y measurements are dual-pass plane mirror (quad-beam) Michelson-type interferometers [ 15 ], with a least-count of 2.5 nm. The interferometer is mounted directly in the vacuum chamber in order to minimize both the dead-path and any environmental influences.…”

Section: Metrology Issues and Implementationmentioning

confidence: 99%

X-ray-lithography mask metrology: Use of transmitted electrons in an SEM for linewidth measurement

Postek¹,

Lowney²,

Vladár³

et al. 1993

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

X-ray masks present a measurement object that is different from most other objects used in semiconductor processing because the support membrane is, by design, x-ray transparent. This characteristic can be used as an advantage in electron beam-based x-ray mask metrology since, depending upon the incident electron beam energies, substrate composition and substrate thickness, the membrane can also be essentially electron transparent. The areas of the mask where the absorber structures are located are essentially x-ray opaque, as well as electron opaque. This paper shows that excellent contrast and signal-to-noise levels can be obtained using the transmitted-electron signal for mask metrology rather than the more commonly collected secondary electron signal. Monte Carlo modeling of the transmitted electron signal was used to support this work in order to determine the optimum detector position and characteristics, as well as in determining the location of the edge in the image profile. The comparison between the data from the theoretically-modeled electron beam interaction and actual experimental data were shown to agree extremely well, particularly with regard to the wall slope characteristics of the structure. Therefore, the theory can be used to identify the location of the edge of the absorber line for linewidth measurement. This work provides one approach to improved x-ray mask linewidth metrology and a more precise edge location algorithm for measurement of feature sizes on x-ray masks in commercial instrumentation. This work also represents an initial step toward the first SEM-based accurate linewidth measurement standard from NIST, as well as providing a viable metrology for linewidth measurement instruments of x-ray masks for the lithography community.

show abstract

Section: Metrology Issues and Implementationmentioning

confidence: 99%

X-ray-lithography mask metrology: Use of transmitted electrons in an SEM for linewidth measurement

Postek¹,

Lowney²,

Vladár³

et al. 1993

J. RES. NATL. INST. STAN.

View full text Add to dashboard Cite

show abstract

“…The Doppler frequency is digitised (TTL) in a fast and hysteresis-free comparator and fed to a counter which registers the number of zero passages per unit of time: NJAf1.dt (5) (6) The Number N of the zero passages is consequently directly proportional to the displacement x of the measuring mirror. For the realisation of a high resolving power and for the recognition of the forward and backward motions of the measuring mirror the measuring and the reference signals are not only compared to each other in a single mixer but in n mixers in the following way:…”

Section: Hf Signalsmentioning

confidence: 99%

<title>Two-frequency laser interferometric path measuring system for extreme velocities with high accuracy</title>

Mueller

Chour

1996

SPIE Proceedings

View full text Add to dashboard Cite

Atwofrequency laser interferometric path measuring system is introduced which has been developed especially for the precision rapid-positioning systems of micro lithographic large-scale instruments and for ultra-precision technology. The modulation frequency of 640 MHz, generated by a highly-stabilised He-Ne-laser allows-in combination with a novel HF signal processing method -measuring velocities up to 6,4 m/s without "loosing" even the least increment (10 nm). It is a further metrological merit that the least increment is not generated by an additional NF interpolation-as was usual so far-but arises from the parallel processing in the HF part.

show abstract

Laser interferometry for precision engineering metrology

Gill¹

1993

Optical Methods in Engineering Metrology

View full text Add to dashboard Cite

A Double Pass Attachment For The Linear And Plane Mirror Interferometer

Cited by 5 publications

References 0 publications

X-ray-lithography mask metrology: Use of transmitted electrons in an SEM for linewidth measurement

X-ray-lithography mask metrology: Use of transmitted electrons in an SEM for linewidth measurement

<title>Two-frequency laser interferometric path measuring system for extreme velocities with high accuracy</title>

Laser interferometry for precision engineering metrology

Contact Info

Product

Resources

About