Name: fabrication of ultra-thin color films with highly absorbing media using oblique angle deposition
Uploaded: 2017-08-29T15:00:00
Description: Watch this Scientific Journal Video about Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition at JoVE.com

This research was supported by Unmanned Vehicles Advanced Core Technology Research and Development Program through the Unmanned Vehicle Advanced Research Center (UVARC) funded by the Ministry of Science, ICT and Future Planning, the Republic of Korea (2016M1B3A1A01937575)

Caution: Some chemicals (i.e., buffered oxide etchant, isopropyl alcohol, etc.) used in this protocol can be hazardous to health. Please consult all relevant material safety data sheets before any sample preparation takes place. Utilize appropriate personal protective equipment (e.g., lab coats, safety glasses, gloves, etc.) and engineering controls (e.g., wet station, fume hood, etc.) when handling etchants and solvents.
1. Preparation of the Si Substrate
<ol>
	<li>U...

<ol>
	<li>Macleod, H. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Thin-film+optical+filters.">Thin-film optical filters.</a> Institute of Physics Publishing. 3, (2001).</li><li>Baumeister, P. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Optical Coating Technology. , (2004).</li><li>Kats, M. A., Blanchard, R., Genevet, P., Capasso, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanometre+optical+coatings+based+on+strong+interference+effects+in+highly+absorbing+media.">Nanometre optical coatings based on strong interference effects in highly absorbing media.</a> Nat. Mater. 12, 20-24 (2013).</li><li>Kats, M. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultra-thin+perfect+absorber+employing+a+tunable+phase+change+material.">Ultra-thin perfect absorber employing a tunable phase change material.</a> Appl. Phys. Lett. 101 (22), 221101 (2012).</li><li>Lee, K. T., Seo, S., Lee, J. Y., Guo, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Strong+resonance+effect+in+a+lossy+medium-based+Optical+Cavity+for+angle+robust+spectrum+filters.">Strong resonance effect in a lossy medium-based Optical Cavity for angle robust spectrum filters.</a> Adv. Mater. 26 (36), 6324-6328 (2014).</li><li>Song, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanocavity+enhancement+for+ultra-thin+film+optical+absorber.">Nanocavity enhancement for ultra-thin film optical absorber.</a> Adv. Mater. 26 (17), 2737-2743 (2014).</li><li>Yoo, Y. J., Lim, J. H., Lee, G. J., Jang, K. I., Song, Y. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultra-thin+films+with+highly+absorbent+porous+media+fine-tunable+for+coloration+and+enhanced+color+purity.">Ultra-thin films with highly absorbent porous media fine-tunable for coloration and enhanced color purity.</a> Nanoscale. 9 (9), 2986-2991 (2017).</li><li>Garahan, A., Pilon, L., Yin, J., Saxena, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Effective+optical+properties+of+absorbing+nanoporous+and+nanocomposite+thin+films.">Effective optical properties of absorbing nanoporous and nanocomposite thin films.</a> J. Appl. Phys. 101 (1), 014320 (2007).</li><li>Moharam, M. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Coupled-wave+analysis+of+two-dimensional+dielectric+gratings.">Coupled-wave analysis of two-dimensional dielectric gratings.</a> Proc. SPIE. 883, 8-11 (1988).</li><li>Robbie, K., Sit, J. C., Brett, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advanced+techniques+for+glancing+angle+deposition.">Advanced techniques for glancing angle deposition.</a> J. Vac. Sci. Technol. B. 16 (3), 1115-1122 (1998).</li><li>Hawkeye, M. M., Brett, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Glancing+angle+deposition:+Fabrication,+properties,+and+applications+of+micro-+and+nanostructured+thin+films.">Glancing angle deposition: Fabrication, properties, and applications of micro- and nanostructured thin films.</a> J. Vac. Sci. Technol. A. 25 (5), 1317-1335 (2007).</li><li>Jang, S. J., Song, Y. M., Yu, J. S., Yeo, C. I., Lee, Y. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Antireflective+properties+of+porous+Si+nanocolumnar+structures+with+graded+refractive+index+layers.">Antireflective properties of porous Si nanocolumnar structures with graded refractive index layers.</a> Opt. Lett. 36 (2), 253-255 (2011).</li><li>Jang, S. J., Song, Y. M., Yeo, C. I., Park, C. Y., Lee, Y. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Highly+tolerant+a-Si+distributed+Bragg+reflector+fabricated+by+oblique+angle+deposition.">Highly tolerant a-Si distributed Bragg reflector fabricated by oblique angle deposition.</a> Opt. Mater. Exp. 1 (3), 451-457 (2011).</li><li>Harris, K. D., Popta, A. C. V., Sit, J. C., Broer, D. J., Brett, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Birefringent+and+Transparent+Electrical+Conductor.">A Birefringent and Transparent Electrical Conductor.</a> Adv. Funct. Mater. 18 (15), 2147-2153 (2008).</li><li>Fairman, H. S., Brill, M. H., Hemmendinger, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=How+the+CIE+1931+color-matching+functions+were+derived+from+Wright-Guild+data.">How the CIE 1931 color-matching functions were derived from Wright-Guild data.</a> Color Research &amp; Application. 22 (1), 11-23 (1997).</li><li>Oliver, J. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electron-beam&#8211;deposited+distributed+polarization+rotator+for+high-power+laser+applications.">Electron-beam&#8211;deposited distributed polarization rotator for high-power laser applications.</a> Opt. Exp. 22 (20), 23883-23896 (2014).</li></ol>

In conventional thin film coatings for coloration3,4,5,6, the color can be controlled by altering different materials and adjusting the thickness. The choice of materials with different refractive indices is limited for tuning various colors. To relax this limitation, we exploited the oblique angle deposition to thin-film color coating. Depending on the deposition angle, the porosity of the Ge ...

In general, the performance of thin-film optical coatings is based on the type of optical interference they produce, such as high reflection or transmission. In dielectric thin-films, optical interference can be obtained simply by satisfying conditions such as quarter wave thickness (&#955;/4n). Interference principles have long been used in various optical applications such as Fabry-Perot interferometers and distributed Bragg reflectors1,2. In recent years, thin film structures using highly absorbent materials such as metals and semiconductors have been widely studied3,4,5,6. Strong optical interference can be obtained by thin-film coating an absorbent semiconductor material on a metal film, which produces non-trivial phase changes in the reflected waves. This type of structure allows ultra-thin coatings which are considerably thinner than dielectric thin-film coatings.
Recently, we studied ways of improving the color tunability and color purity of highly absorbent thin-films using porosity7. By controlling the porosity of the deposited film, the effective refractive index of the thin-film medium can be changed8. This change in the effective refractive index allows the optical characteristics to be improved. Based on this effect, we designed ultra-thin color films with different thicknesses and porosities by calculations using rigorous coupled wave analysis (RCWA)9. Our design presents colors with different film thicknesses at each porosity7.
We employed a simple method, oblique angle deposition, to control the porosity of highly absorbent thin-film coatings. The oblique angle deposition technique basically combines a typical deposition system, such as an electron beam evaporator or thermal evaporator, with a tilted substrate10. The oblique angle of incident flux creates atomic shadowing, which produces areas that the vapor flux cannot reach directly11. The oblique angle deposition technique has been widely used in various thin-film coating applications12,13,14.
In this work, we detail the processes for fabricating ultra-thin color films by oblique deposition using an electron beam evaporator. Also, additional methods for large-area processing are presented separately. In addition to the process steps, some notes that should be taken into consideration during the fabrication process are explained in detail.
We also review processes for measuring the reflectance of the fabricated samples and converting them into color information for analysis, so that they can be expressed in CIE color coordinates and RGB values15. Furthermore, some issues to consider in the fabrication process of ultra-thin color films are discussed.

<table border="0" cellpadding="0" cellspacing="0" width="757">
	<tbody>
		<tr height="23">
			<td height="23" style="height:23px;width:216px;">&#160;KVE-2004L</td>
			<td style="width:185px;">Korea Vacuum Tech. Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">E-beam evaporator system</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Cary 500</td>
			<td style="width:185px;">Varian, USA</td>
			<td style="width:129px;"></td>
			<td>UV-Vis-NIR spectrophotometer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">T1-H-10</td>
			<td style="width:185px;">Elma</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Ultrasonic bath</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">HSD150-03P</td>
			<td style="width:185px;">Misung Scientific Co., Ltd</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Hot plate</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Isopropyl Alcohol (IPA)</td>
			<td style="width:185px;">OCI Company Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Isopropyl Alcohol (IPA)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Buffered Oxide Etch 6:1</td>
			<td style="width:185px;">Avantor</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Buffered Oxide Etch 6:1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:216px;">Acetone</td>
			<td style="width:185px;">OCI Company Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">Acetone</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">4inch Silicon Wafer</td>
			<td style="width:185px;">Hi-Solar Co., Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">4inch Silicon Wafer (P-100, 1-20 ohm.cm, Single side polished, Thickness: 440&#177;20&#956;m)</td>
		</tr>
		<tr height="63">
			<td height="63" style="height:63px;width:216px;">2inch Silicon Wafer</td>
			<td style="width:185px;">Hi-Solar Co., Ltd.</td>
			<td style="width:129px;"></td>
			<td style="width:227px;">2inch Silicon Wafer (P-100, 1-20 ohm.cm, Single side polished, Thickness: 440&#177;20&#956;m)</td>
		</tr>
	</tbody>
</table>

fabrication of ultra-thin color films with highly absorbing media using oblique angle deposition

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present an advanced method for fabricating ultra-thin color films with improved characteristics. The proposed process addresses several fabrication issues, including large area processing. Specifically, the protocol describes a process for fabricating ultra-thin color films using an electron beam evaporator for oblique angle deposition of germanium (Ge) and gold (Au) on silicon (Si) substrates.&#160; Film porosity produced by the oblique angle deposition induces color changes in the ultra-thin film. The degree of color change depends on factors such as deposition angle and film thickness. Fabricated samples of the ultra-thin color films showed improved color tunability and color purity. In addition, the measured reflectance of the fabricated samples was converted into chromatic values and analyzed in terms of color. Our ultra-thin film fabricating method is expected to be used for various ultra-thin film applications such as flexible color electrodes, thin film solar cells, and optical filters. Also, the process developed here for analyzing the color of the fabricated samples is broadly useful for studying various color structures.

Figure 2a shows images of the 2 cm x 2 cm fabricated samples. The samples were fabricated so that the films had different thicknesses (i.e., 10 nm, 15 nm, 20 nm, and 25 nm) and were deposited at different angles (i.e., 0&#176;, 30&#176;, 45&#176;, and 70&#176;). The color of the deposited films changes depending on the combination of both the thickness of the samples and the deposition angle. The changes in color result from changes in the porosity of the film. Depending on...

Watch this Scientific Journal Video about Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition at JoVE.com

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition

We present a detailed method for fabricating ultra-thin color films with improved characteristics for optical coatings. The oblique angle deposition technique using an electron beam evaporator allows improved color tunability and purity. Fabricated films of Ge and Au on Si substrates were analyzed by reflectance measurements and color information conversion.

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present ...

Research

JoVE Journal

Engineering

Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition

Nanosecond Pulsed  Laser Deposition (PLD) in the presence of a background gas allows the deposition  of metal oxides with tunable morphology, structure, ...

Formation of Thick Dense Yttrium Iron Garnet Films Using Aerosol Deposition

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% ...

Speciation and Bioavailability Measurements of Environmental Plutonium Using Diffusion in Thin Films

The biological uptake of plutonium (Pu) in aquatic ecosystems is of particular concern since it is an alpha-particle emitter with long half-life which can ...

Indirect Fabrication of Lattice Metals with Thin Sections Using Centrifugal Casting

One of the typical methods to manufacture 3D lattice metals is the direct-metal additive manufacturing (AM) process such as Selective Laser Melting (SLM) ...

A Fabrication Method for Highly Stretchable Conductors with Silver Nanowires

Stretchable electronics are identified as a key technology for electronic applications in the next generation. One of the challenges in fabrication of ...

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

Electrospray Deposition of Uniform Thickness Ge23Sb7S70 and As40S60 Chalcogenide Glass Films

Solution-based electrospray film deposition, which is compatible with continuous, roll-to-roll processing, is applied to chalcogenide glasses. Two ...

Preparation of Large-area Vertical 2D Crystal Hetero-structures Through the Sulfurization of Transition Metal Films for Device Fabrication

We have demonstrated that through the sulfurization of transition metal films such as molybdenum (Mo) and tungsten (W), large-area and uniform transition ...

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

The goal of this protocol is to present how to perform spin- and angle-resolved photoemission spectroscopy combined with polarization-variable 7-eV laser ...

Fabricating Reactive Surfaces with Brush-like and Crosslinked Films of Azlactone-Functionalized Block Co-Polymers

In this paper, fabrication methods that generate novel surfaces using the azlactone-based block co-polymer, poly (glycidyl methacrylate)-block-poly (vinyl ...