A comprehensive simulation model of the performance of photochromic films in absorbance-modulation-optical-lithography

Journal Article · Tue Mar 15 00:00:00 EDT 2016 · AIP Advances

DOI:https://doi.org/10.1063/1.4944489· OSTI ID:22611617

Majumder, Apratim; Helms, Phillip L.; Menon, Rajesh ^[1]; Andrew, Trisha L. ^[2]

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1. Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)
2. Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

Optical lithography is the most prevalent method of fabricating micro-and nano-scale structures in the semiconductor industry due to the fact that patterning using photons is fast, accurate and provides high throughput. However, the resolution of this technique is inherently limited by the physical phenomenon of diffraction. Absorbance-Modulation-Optical Lithography (AMOL), a recently developed technique has been successfully demonstrated to be able to circumvent this diffraction limit. AMOL employs a dual-wavelength exposure system in conjunction with spectrally selective reversible photo-transitions in thin films of photochromic molecules to achieve patterning of features with sizes beyond the far-field diffraction limit. We have developed a finite-element-method based full-electromagnetic-wave solution model that simulates the photo-chemical processes that occur within the thin film of the photochromic molecules under illumination by the exposure and confining wavelengths in AMOL. This model allows us to understand how the material characteristics influence the confinement to sub-diffraction dimensions, of the transmitted point spread function (PSF) of the exposure wavelength inside the recording medium. The model reported here provides the most comprehensive analysis of the AMOL process to-date, and the results show that the most important factors that govern the process, are the polarization of the two beams, the ratio of the intensities of the two wavelengths, the relative absorption coefficients and the concentration of the photochromic species, the thickness of the photochromic layer and the quantum yields of the photoreactions at the two wavelengths. The aim of this work is to elucidate the requirements of AMOL in successfully circumventing the far-field diffraction limit.

• OSTI ID: 22611617
• Journal Information: AIP Advances, Vol. 6, Issue 3; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 2158-3226
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABSORPTION
ABUNDANCE
BEAMS
CONCENTRATION RATIO
CONFINEMENT
DIFFRACTION
ELECTROMAGNETIC RADIATION
FINITE ELEMENT METHOD
ILLUMINANCE
LAYERS
MODULATION
MOLECULES
PHOTONS
POLARIZATION
RESOLUTION
SEMICONDUCTOR MATERIALS
SIMULATION
THIN FILMS
WAVELENGTHS