&lt;title&gt;Optical characterization of polycrystalline silicon thin films&lt;/title&gt;

Tiwald

et al. 2001

phys. stat. sol. (a)

The shift towards shorter wavelengths in the lithographic process has been the driving force for development of a commercial spectroscopic ellipsometer covering the vacuum ultraviolet (VUV) spectrum. Understanding the optical properties of thin films and substrate materials at short wavelengths (193 nm, 157 nm, and shorter) is necessary to develop the lithographic process. Lithography applications include optical coatings, photoresists, AR films, and masks. We present results for both single and multi-layer structures important to this industry. A complete description of the thin film optical properties can be used to track process changes or variations in sample structure. As an example, we compare the measured index for three oxynitrides that were subjected to different process conditions. In addition to lithography applications, VUV ellipsometry has many other potential applications. A variety of other materials have been characterized, often incorporating generalized ellipsometry to investigate anisotropic optical properties. The ordinary and extraordinary dielectric functions for bulk 4H SiC were measured over the wide spectral range from 0.73 to 8.5 eV.

Section: Wide Spectral Rangementioning

confidence: 99%

Materials Characterization in the Vacuum Ultraviolet with Variable Angle Spectroscopic Ellipsometry

Wágner¹,

Tiwald

et al. 2001

phys. stat. sol. (a)

“…thin films of amorphous and poly-silicon. [4,5] Figures 2(a,b) illustrate the significant changes in optical constants for silicon films under varying process conditions.…”

Section: Amorphous Silicon and Multi-layersmentioning

confidence: 99%

Characterizing Thin Films in the Flat Panel Display Industry with Variable Angle Spectroscopic Ellipsometry (VASE®)

Symp Digest of Tech Papers

Synowicki

Hale

et al. 1998

Variable Angle Spectroscopic Ellipsometry (VASE ® ) is a common characterization method for thin films used in the flat panel display industry. It is a precise and non-destructive technique for determining refractive index and film thickness for single or multi-layered films. The film properties can be mapped to ensure uniformity over large area panels. The application of VASE ® for flat panel applications will be reviewed -including measurements of amorphous silicon, silicon nitride, silicon dioxide, liquid crystals, indium tin oxide (ITO), and multi-layers of these materials.

“…This effect is used to estimate the degree of crystallinity in polysilicon films for display applications. 11 The imaginary dielectric function for SiC is shown in Fig. 5.…”

Section: 10mentioning

confidence: 99%

Progress in spectroscopic ellipsometry: Applications from vacuum ultraviolet to infrared

Journal of Vacuum Science &Amp; Technology A: Vacuum, Surfaces, and Films

Bungay

Synowicki

et al. 2003

Spectroscopic ellipsometry ͑SE͒ is a noncontact and nondestructive optical technique for thin film characterization. In the past 10 yr, it has migrated from the research laboratory into the semiconductor, data storage, display, communication, and optical coating industries. The wide acceptance of SE is a result of its flexibility to measure most material types: dielectrics, semiconductors, metals, superconductors, polymers, biological coatings, and even multilayers of these materials. Measurement of anisotropic materials has also made huge strides in recent years. Traditional SE measurements cover the ultraviolet, visible, and near infrared wavelengths. This spectral range is now acquired within seconds with high accuracy due to innovative optical configurations and charge coupled device detection. In addition, commercial SE has expanded into both the vacuum ultraviolet ͑VUV͒ and midinfrared ͑IR͒. This wide spectral coverage was achieved by utilizing new optical elements and detection systems, along with UV or Fourier transform IR light sources. Modern instrumentation is now available with unprecedented flexibility promoting a new range of possible applications. For example, the VUV spectral region is capable of characterizing lithographic materials for 157 nm photolithography. The VUV also provides increased sensitivity for thin layers ͑e.g., gate oxides or self-assembled monolayers͒ and allows investigation of high-energy electronic transitions. The infrared spectral region contains information about semiconductor doping concentration, phonon absorption, and molecular bond vibrational absorptions. In this work, we review the latest progress in SE wavelength coverage. Areas of significant application in both research and industrial fields will be surveyed, with emphasis on wavelength-specific information content.