skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity

Abstract

Planetary rotation systems incorporating forward- and counter-rotating planets are used as a means of increasing coating-system capacity for large oblong substrates. Comparisons of planetary motion for the two types of rotating systems are presented based on point tracking for multiple revolutions, as well as comparisons of quantitative thickness and uniformity. Counter-rotation system geometry is shown to result in differences in thin-film thickness relative to standard planetary rotation for precision optical coatings. As a result, this systematic error in thin-film thickness will reduce deposition yields for sensitive coating designs.

Authors:
 [1]
  1. Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
Publication Date:
Research Org.:
Univ. of Rochester, Rochester, NY (United States). Lab. for Laser Energetics
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1372102
Grant/Contract Number:
NA0001944
Resource Type:
Journal Article: Accepted Manuscript
Journal Name:
Applied Optics
Additional Journal Information:
Journal Volume: 56; Journal Issue: 18; Journal ID: ISSN 0003-6935
Publisher:
Optical Society of America (OSA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; deposition and fabrication; materials and process characterization

Citation Formats

Oliver, J. B. Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity. United States: N. p., 2017. Web. doi:10.1364/AO.56.005121.
Oliver, J. B. Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity. United States. doi:10.1364/AO.56.005121.
Oliver, J. B. 2017. "Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity". United States. doi:10.1364/AO.56.005121.
@article{osti_1372102,
title = {Impact of a counter-rotating planetary rotation system on thin-film thickness and uniformity},
author = {Oliver, J. B.},
abstractNote = {Planetary rotation systems incorporating forward- and counter-rotating planets are used as a means of increasing coating-system capacity for large oblong substrates. Comparisons of planetary motion for the two types of rotating systems are presented based on point tracking for multiple revolutions, as well as comparisons of quantitative thickness and uniformity. Counter-rotation system geometry is shown to result in differences in thin-film thickness relative to standard planetary rotation for precision optical coatings. As a result, this systematic error in thin-film thickness will reduce deposition yields for sensitive coating designs.},
doi = {10.1364/AO.56.005121},
journal = {Applied Optics},
number = 18,
volume = 56,
place = {United States},
year = 2017,
month = 6
}

Journal Article:
Free Publicly Available Full Text
This content will become publicly available on June 12, 2018
Publisher's Version of Record

Save / Share:
  • Cited by 1
  • Variations in deposition rate are superimposed on a thin-film–deposition model with planetary rotation to determine the impact on film thickness. Variations in magnitude and frequency of the fluctuations relative to the speed of planetary revolution lead to thickness errors and uniformity variations up to 3%. Sufficiently rapid oscillations in the deposition rate have a negligible impact, while slow oscillations are found to be problematic, leading to changes in the nominal film thickness. Finally, superimposing noise as random fluctuations in the deposition rate has a negligible impact, confirming the importance of any underlying harmonic oscillations in deposition rate or source operation.
  • To predict the thin film thickness distribution in a quantitative way, a theoretical calculation was conducted according to the cosine law approach for off-axis sputtering. The numerical calculation was focused on the optimal geometry instead of the thickness distribution itself, which took into account several variables including the target-to-substrate distance, the off-axis displacement, the emission characteristic, the width of the erosion groove, and the film thickness requirement. The effects of these variables on the optimal geometry were analyzed individually and the subsequent combined equations for optimal geometry were summarized. Thus, the combined equations were multivariable functions. These equations were simplemore » and general and could be applied directly. For many situations, these equations eliminate the need to perform the complex, detailed calculation otherwise needed for each deposition geometry variant.« less
  • Multilayer coatings on large substrates with increasingly complex spectral requirements are essential for a number of optical systems, placing stringent requirements on the error tolerances of individual layers. Each layer must be deposited quite uniformly over the entire substate surface since any nonuniformity will add to the layer-thickness error level achieved. A deposition system containing a planetary rotation system with stationary uniformity masking is modeled, with refinements of the planetary gearing, source placement, and uniformity mask shape being utilized to achieve an optimal configuration. The impact of improper planetary gearing is demonstrated theoretically, as well as experimentally, providing more comprehensivemore » requirements than simply avoiding repetition of previous paths through the vapor plume, until all possible combinations of gear teeth have been used. Deposition efficiency and the impact of changing vapor plume conditions on the uniformity achieved are used to validate improved source placement.« less