About Instruments Today No. 222

Thin Solid Films

Alternative Nano-plasmonic Material-Titanium Nitride

Yi-Jun Jen, Meng-Jie Lin, Teh-Li Chan

In this article, we introduce a new plasmonic material, TiN. TiN owns excellent refractory properties, chemically stability and high melting temperatures of over 2000oC. As a plasmonic material, TiN has been applied in optical nanoantennas, energy harvesting devices, data storage, surface-enhanced Raman scattering, and biophotonics. The carrier concentration and mobility of TiN are sufficiently high to generate negative real permittivity and low material loss. Our work used glancing angle deposition to grow TiN nanorod arrays in a sputtering system. The permittivity of TiN can be tuned by varying deposition conditions including argon/nitrogen (Ar/N) flow ratios and substrate bias. We show that the localized plasmonic resonance of a TiN nanorod array is varied with deposition condition.

Introduction to Applications of the Advanced Thin Film Technologies

Po-Kai Chiu, Donyau Chiang, Chien-Nan Hsiao, Fong-Zhi Chen

This article gives a brief introduction of thin film technologies which can apply for the variety of goods. The application fields include the sunglasses or art decorations used in the daily life, the camera lens used in consumer devices, and extend to image capture device used in the space instrument subjected to strictly harsh environment, the optical components used in semiconductor and packaging equipment required for the precise and accurate operations. In addition, the applications of thin film technologies are also for the optical components, sensors and image devices related to the optics which are for biomedical industries and automobile industries. Within a few decades, the thin film technologies become an indispensable technology to produce the key and functional parts in all fields and an invisible but profoundly necessary backup for the high tech industries. The thin film technology continues to be advanced with the improvements of the other technologies. In this article, we report what optical components we have developed and the reasons why we have to invent.

Applications of Atomic Layer Deposition on Energy Materials

Chih-Chieh Wang, Chi-Chung Kei

Developments of clean, renewable and sustainable energy have been received more attentions due to the limited natural resources and serious global warming in earth. In this study, atomic layer deposition (ALD) with excellent coating conformity and precise thickness control in atomic scale is proposed to fabricate and modify energy materials, applying for photocatalytic water splitting for hydrogen generation and lithium ion battery. Preliminary study shows that the performances of the energy materials are improved.

Transparent Hard Coating Deposited by Closed Field Magnetron Sputtering with High-power Impulse Source

Bo-Huei Liao, Chien-Nan Hsio, Ming-Hua Shio, Yu-Wei Lin, Shen-Hui Chen

In this research, the plasma technique has been implemented to develop the closed field magnetron sputtering to improve the ability of sputtering reaction, the stability of the plasma and deposition rate. Then high power impulse magnetron sputtering is applied to increase the deposition energy and packing density. Next, Si3N4 and SiOxNy films are deposited with the novel deposition technique and the transparent hard coating is designed and manufactured. A 3-layer of AR coating in the DUV range is designed and fabricated on double side quartz and a high transmittance of 99.22% is attained at 244 nm. A four-layer coating is deposited on both sides of a silicon substrate. The average transmittance from 3200-4800 nm is 99.0 % and the highest transmittance is 99.97 % around 4200 nm. A film structure of 6-layer transparent hard coating/glass/4-layer AR coating is designed and deposited. Its average transmittance is 96.0 % in the visible range while its hardness is 21 GPa .

Study of InN Nanocolumns on Ultra-thin Si3N4 Buffer Layer by RF Plasma Nitridation

Wei-Chun Chen, Tung-Yuan Yu

InN is a potential material for various devices such as infrared light emitters and high efficiency optoelectronic device because of it is high mobility (~3500 cm2/v-s) and narrow band gap of 0.65-0.7 eV. Also, Al, Ga-doped InN alloys has band gap of wide range in the 0.65-6.2 eV. However, the InN is difficult to grow high-crystalline-quality InN owing to its low dissociation temperature and the lack of lattice-matched substrates. Therefore, the various properties of InN films have not been fully confirmed. In the study, the SixNy thin films was grown on surface of Si substrate for nitridation by RF-N2 plasma exposure. And then the InN nanocolumns were prepared on nitrided SixNy/Si(111) via radio-frequency (RF) metal–organic molecular beam epitaxy (MOMBE) with various substrate temperatures. We discussed the effect of various condition on the chemical and structural properties of SixNy ultra-thin film and InN nanocolumns. The surface and interface chemical composition and surface morphology are investigated by using transmission electron microscope (TEM), ellipsometer, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM).  TEM image indicated that the SixNy film shows relatively surface of smooth with 1 sccm N2 and 300 W of RF power. Based on X-ray diffraction analysis, highly <0001>-oriented hexagonal InN nanocolumns were grown on the nitride Si(111) substrates. Transmission electron microscopy analysis indicated that the InN nanocolumns were single-phase wurtzite crystals having preferred orientations along the c-axis. SEM images show that the deviation angle of InN nanocolums was measured to evaluate the alignment of arrays. Also, the XPS results indicated that the InN/SixNy were measured at nearly chemical stoichiometric.

The Introduction to kMLLS Clustering and It's Applications to EELS Analysis of Thin Films

Ren-Fong Cai, Mu-Tung Chang, Shen-Chuan Lo, Chien-Chun Chen

In recent years, combining a Cs-corrected scanning transmission electron microscope with an EDS and/or EELS detector has become an indispensable tool for material characterization. With a proper data processing, atomic structures, chemical compositions, and electronic configurations of materials can be resolved in a spectrum image. In this article, we introduce a novel algorithm – kMLLS clustering, which combines the advantages of k-means clustering and multiple linear least squares fitting, to accurately extract the spectra of the endmembers and the corresponding distribution from a spectrum image. kMLLS clustering has the great potential to the in-line application and provides significant insights into materials.

Development of Smart Machinery and Digital Manufacturing with 3D Printing

Yun-Peng Yeh, Jeng-Ywan Jeng

3D printing is not just a rapid prototyping in the past, it is now one of the important emerging technologies in "Industry 4.0" and "Smart Machinery" worldwide, which is covering mechanics, optoelectronics, materials and information, to innovative design and manufacturing of the applications and new business service model. This innovative manufacturing process brings traditional manufacturing methods into the era of highly customized mass production digital manufacturing technology. In 3D printing technology, if the material pattern formation and energy supply control are separated, high-speed and high-precision digital manufacturing can be achieved. Among of 3D printing technology, binder jetting and liquid VAT photopolymerization techniques, in which the adhesive spray printing method and the light enhanced resin curing method, can define the accurate forming position through a high-speed multi-nozzle or a digital light source, and apply thermal energy or ultraviolet light source to materials at the defined position. It can be completed on a single machine with extremely direct high laser power for quick deposition and combine both efficiency and advantages of automatic manufacturing and functional materials to achieve high speed and high precision digital manufacturing.