Alternating grazing incidence dark-field scanning optical microscopy for dimensional measurements

Bodermann, Bernd; Michaelis, W.; Diener, Alexander C.; Mirandé, W.

doi:10.1117/12.472235

Cited by 8 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In previous papers we reported on the applicability of AGID for measurements on deep etched silicon structures [4,5]. However, for metallic structures like Chromium bars on silica substrates this method should even work better than for silicon structures, because the higher absorption of the metal at X = 532 nm leads to a better coincidence of the edge positions and the diffraction peaks [5].…”

Section: Agid: Measurements and Simulationsmentioning

confidence: 98%

“…However, for metallic structures like Chromium bars on silica substrates this method should even work better than for silicon structures, because the higher absorption of the metal at X = 532 nm leads to a better coincidence of the edge positions and the diffraction peaks [5]. Therefore we started systematic measurements on masks and compare these with theoretical calculations based on the Rigorous Coupled-Wave Analysis method [6].…”

Section: Agid: Measurements and Simulationsmentioning

confidence: 98%

“…Experimental setup AGID The first method, alternating grazing incidence dark field microscopy (AGID), was already described in detail elsewhere [4,5]. We use a one dimensional scanning optical microscope in reflection mode.…”

mentioning

confidence: 99%

See 2 more Smart Citations

<title>New methods for CD measurements on photomasks using dark field optical microscopy</title>

Bodermann

Michaelis

Diener

et al. 2003

19th European Conference on Mask Technology for Integrated Circuits and Microcomponents

Self Cite

View full text Add to dashboard Cite

We present novel methods of dark field optical microscopy for CD measurements on photomasks in the sub lambda regime. Optical CD inspection systems usually suffer from limited resolution and from linear and nonlinear superposition of the light diffracted at both edges of a line structure (optical proximity effects). These disadvantages partly can be overcome using alternating grazing incidence illumination of the specimen, where the angle of incidence of the iilumination is perpendicular to the edges or grooves of the specimen. Especially for s-polarised light the diffraction efficiencies of the edges directed towards the illumination are at least an order of magnitude stronger than that of the averted edges. Thus an efficient suppression of optical proximity effects is achieved. Additionally a reduction of the widths of the diffraction limited images of structure edges due to a high pass characteristic of the optical image takes place. Both effects result in a significantly increased resolution power. We developed both a reflection mode (alternating grazing incidence dark field microscopy, AGID) and a transmission mode method (Frustrated internal total reflection microscopy, FIRM). Line width measurements on high quality photomasks will be presented. The experimental results will be compared with theoretical simulations and the applicability for sub lambda structures will be discussed.

show abstract

Section: Agid: Measurements and Simulationsmentioning

confidence: 98%

Section: Agid: Measurements and Simulationsmentioning

confidence: 98%

See 1 more Smart Citation

<title>New methods for CD measurements on photomasks using dark field optical microscopy</title>

Bodermann

Michaelis

Diener

et al. 2003

19th European Conference on Mask Technology for Integrated Circuits and Microcomponents

Self Cite

View full text Add to dashboard Cite

show abstract

“…Recently at the ITO in Stuttgart phase shifting polarisation-interference-microscopy [4][5][6] and at the PTB in Braunschweig two new methods of dark field optical microscopy have been developed and investigated [7][8][9]. These new methods show different but interesting features.…”

Section: Introductionmentioning

confidence: 99%

Comparative linewidth measurements on chrome and MoSi structures using newly developed microscopy methods

et al. 2003

Self Cite

View full text Add to dashboard Cite

Inspection and linewidths measurements of subwavelength structures using optical microscopy are severely confined both by the limited resolution and by a manifold of light-structure interactions affecting the optical image. To receive a better understanding of these interactions and/or to overcome these limitations, new microscopy methods have been developed: Polarisation-interference-microscopy permits the accurate measurement of the birefringence which is induced by the form of the structures. By interferometric comparison of the TE and TM-polarized image this method provides selective edge detection and localisation in the subwavelength regime because the polarisation difference is situated at the topographical changes of the structure. Two new methods of dark field microscopy ,"alternating grazing incidence dark field microscopy" and "frustrated internal total reflection microscopy", make it possible to suppress optical proximity effects and to overcome the resolution limit of conventional dark field microscopy.For a characterisation of the qualitative and quantitative influence of different variables on measurements of the size of subwavelength structures we performed comparative linewidths measurements on Chrome and phase shifting MoSi photomask structures. The deliverables are compared with rigorous numerical simulations.

show abstract

“…At the PTB a dark field microscopy method was developed [1], which allows to determine lateral structures with dimensions below the well-known classical resolution limit x ∆ :…”

Section: Introductionmentioning

confidence: 99%

Improved optical linewidth measurement by means of alternating dark field illumination and model-based evaluation

2005

Self Cite

View full text Add to dashboard Cite

The dark field microscopy method with alternating grazing incidence illumination (AGID), developed at the PTB, offers the possibility to measure structures with lateral dimensions below the classical resolution limit. Moreover, this method offers the advantage of better dimensional measurements of phase objects, since higher contrasts compared to conventional bright field microscopy are obtained. As an example, the AGID-method can be used for the determination of linewidths on photomasks or wafers. A newly developed prototype measuring system based on the alternating dark field illumination is be presented. This system uses two diode lasers with the wavelength 374 nm as lightsources. This new method is be compared with conventional bright field microscopy. The distribution of intensity of an image of a given structure depends on the illumination and the geometrical parameters as well on the optical parameters. In particular the dependence on the polarization and the angle of incidence of the illumination is discussed. For modeling of the intensity distribution in the image we are using two different rigorous diffraction theories. On the one hand we use the rigorous coupled wave analysis (RCWA) method for the calculation of the diffracted electric and magnetic fields and on the other hand the finite elements (FEM) method. These two models are used for determining the linewidth from measurement data of the new prototype system. It will be shown that the newly developed system is a suitable tool for optical linewidth measurements which represents a meaningful addition to existing optical linewidth measurement systems.

show abstract

Alternating grazing incidence dark-field scanning optical microscopy for dimensional measurements

Cited by 8 publications

References 0 publications

<title>New methods for CD measurements on photomasks using dark field optical microscopy</title>

<title>New methods for CD measurements on photomasks using dark field optical microscopy</title>

Comparative linewidth measurements on chrome and MoSi structures using newly developed microscopy methods

Improved optical linewidth measurement by means of alternating dark field illumination and model-based evaluation

Contact Info

Product

Resources

About