Enhanced microlithography using coated objectives and image duplication

Miklós Erdélyi, Z. Bor, Gábor Szabó, Frank K. Tittel

Research output: Conference contribution

4 Citations (Scopus)

Abstract

Two processes were investigated theoretically using both a scalar wave optics model and a microlithography simulation tool (Solid-C). The first method introduces a phase- transmission filter into the exit pupil plane. The results of both the scalar optics calculation (aerial image) and the Solid-C simulation (resist image) show that the final image profile is optimum, when the exit pupil plane filter is divided into two zones with the inner zone having a phase retardation of (pi) rad with respect to the outer one and the ratio of the radii of the zones is 0.3. Using this optimized filter for the fabrication of isolated contact holes, the focus-exposure process window increases significantly, and the depth of focus (DOF) can be enhanced by a factor of 1.5 to 2. The second technique enhances the DOF of the aerial image by means of a birefringent plate inserted between the projection lens and the wafer. As the shift in focus introduced by the plate strongly depends on the refractive index, two focal points will appear when using a birefringent plate instead of an isotropic plate: the first one is created by the ordinary, and the second one is created by the extraordinary ray. The distance between these images can be controlled by the thickness of the plate. The results of the calculations show that application of a thin but strongly birefringent material is a better candidate than using a slightly birefringent but thick plate, since aberrations proportional to the thickness can cause undesirable effects.

Original languageEnglish
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
Pages579-589
Number of pages11
Volume3334
DOIs
Publication statusPublished - 1998
EventOptical Microlithography XI - Santa Clara, CA, United States
Duration: febr. 25 1998febr. 25 1998

Other

OtherOptical Microlithography XI
CountryUnited States
CitySanta Clara, CA
Period2/25/982/25/98

Fingerprint

Microlithography
Duplication
Lithography
Depth of Focus
Optics
pupils
Aerial Image
filters
Filter
Antennas
optics
scalars
thick plates
Birefringence
Aberrations
Scalar
Contact Hole
Lenses
Refractive index
Process Window

ASJC Scopus subject areas

  • Applied Mathematics
  • Computer Science Applications
  • Electrical and Electronic Engineering
  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Erdélyi, M., Bor, Z., Szabó, G., & Tittel, F. K. (1998). Enhanced microlithography using coated objectives and image duplication. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 3334, pp. 579-589) https://doi.org/10.1117/12.310787

Enhanced microlithography using coated objectives and image duplication. / Erdélyi, Miklós; Bor, Z.; Szabó, Gábor; Tittel, Frank K.

Proceedings of SPIE - The International Society for Optical Engineering. Vol. 3334 1998. p. 579-589.

Research output: Conference contribution

Erdélyi, M, Bor, Z, Szabó, G & Tittel, FK 1998, Enhanced microlithography using coated objectives and image duplication. in Proceedings of SPIE - The International Society for Optical Engineering. vol. 3334, pp. 579-589, Optical Microlithography XI, Santa Clara, CA, United States, 2/25/98. https://doi.org/10.1117/12.310787
Erdélyi M, Bor Z, Szabó G, Tittel FK. Enhanced microlithography using coated objectives and image duplication. In Proceedings of SPIE - The International Society for Optical Engineering. Vol. 3334. 1998. p. 579-589 https://doi.org/10.1117/12.310787
Erdélyi, Miklós ; Bor, Z. ; Szabó, Gábor ; Tittel, Frank K. / Enhanced microlithography using coated objectives and image duplication. Proceedings of SPIE - The International Society for Optical Engineering. Vol. 3334 1998. pp. 579-589
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