Multiple patterning technology has become an essential process. In the commonly used self-aligned multiple patterning process, the spacer should be dense at low temperatures and have a high elastic modulus. To meet these conditions, many... more
Multiple patterning technology has become an essential process. In the commonly used self-aligned multiple patterning process, the spacer should be dense at low temperatures and have a high elastic modulus. To meet these conditions, many thin-film deposition methods, such as plasma-enhanced atomic layer deposition, have been studied. We investigated remote plasma atomic layer deposition (RPALD) technology with a DC positive bias. After applying bias voltage to the plasma region, changes in the plasma properties, such as density and flux, were examined and applied to SiO2 deposition. When DC positive bias was applied, the sheath voltage decreased, causing an increase in the radical density, which contributed to the surface reaction. In an elastic recoil detection analysis, the application of 200 V reduced the hydrogen content of the film from 11.89% to 10.07% compared with no bias; an increase in SiO2 film density from 2.32 to 2.35 g cm−3 was also measured. The elastic modulus and ha...
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Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of microelectronic devices because of their low resistivity and high work-function. However the material cost of Ru is very expensive and it... more
Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of microelectronic devices because of their low resistivity and high work-function. However the material cost of Ru is very expensive and it usually takes long initial nucleation time on SiO2 during chemical deposition. Therefore many researchers have focused on how to enhance the initial growth rate on SiO2 surface. There are two methods to deposit Ru film with atomic layer deposition (ALD); the one is thermal ALD using dilute oxygen gas as a reactant, and the other is plasma enhanced ALD (PEALD) using NH3 plasma as a reactant. Generally, the film roughness of Ru film deposited by PEALD is smoother than that deposited by thermal ALD. However, the plasma is not favorable in the application of high aspect ratio structure. In this study, we used a bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a metal organic precursor for both thermal and plasma enhanced ALDs. In order to reduce initial nuc...
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Tin disulfide (SnS2) has emerged as a promising two-dimensional (2D) material due to its excellent electrical and optical properties. However, research into 2D SnS2 has mainly focused on its synthesis procedures and applications; its... more
Tin disulfide (SnS2) has emerged as a promising two-dimensional (2D) material due to its excellent electrical and optical properties. However, research into 2D SnS2 has mainly focused on its synthesis procedures and applications; its stability to humidity and temperature has yet to be studied. In this work, 2D SnS2 thin films were grown by atomic layer deposition (ALD) and characterized by various tools, such as X-ray diffraction, Raman analysis, and transmission electron spectroscopy. Characterization reveals that ALD-grown SnS2 thin films are a high-quality 2D material. After characterization, a four-inch-wafer-scale uniformity test was performed by Raman analysis. Owing to the quality, large-area growth enabled by the ALD process, 98.72% uniformity was obtained. Finally, we calculated the thermodynamic equations for possible reactions between SnS2 and H2O to theoretically presurmise the oxidation of SnS2 during accelerated humidity and temperature testing. After the accelerated humidity and temperature test, X-ray diffraction, Raman analysis, and Auger electron spectroscopy were performed to check whether SnS2 was oxidized or not. Our data revealed that 2D SnS2 thin films were stable at humid conditions.
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Tungsten‐nitrogen‐carbide (WNxCy) thin films were investigated as the metal gate of complementary metal‐oxide‐semiconductor (CMOS) devices. WNxCy thin films were deposited by employing the remote plasma atomic layer deposition (RPALD)... more
Tungsten‐nitrogen‐carbide (WNxCy) thin films were investigated as the metal gate of complementary metal‐oxide‐semiconductor (CMOS) devices. WNxCy thin films were deposited by employing the remote plasma atomic layer deposition (RPALD) using a bis(tert‐butylimido) bis (dimethylamido) tungsten (BTBMW) precursor and hydrogen plasma as a reactant. The growth rate of the WNxCy films was about 0.12 nm/cycle. X‐ray diffraction (XRD) analysis indicated that the films consisted of a mixture of tungsten carbide and tungsten nitride phases. The atomic force microscope (AFM) analysis further confirmed that the WNxCy film surfaces deposited by RPALD were smooth. In addition, the chemical bonding state analysis showed that the WNxCy films consisted of WN, WC, and WO phases. To measure the work function of the WNxCy film, a MOSCAP (metal oxide semiconductor capacitor) stack was fabricated and the flat band voltage was measured by current–voltage (C–V) measurements. A WNxCy work function value of 4...
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The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposition (ALD) system for thin film encapsulation (TFE) of flexible organic light-emitting diode (OLED) displays at low temperatures... more
The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposition (ALD) system for thin film encapsulation (TFE) of flexible organic light-emitting diode (OLED) displays at low temperatures (<100 °C). In this paper, the authors report the excellent moisture barrier properties of Al2O3 films deposited on 2G glass substrates of an industrially relevant size (370 × 470 mm2) using the newly developed ALD system. This new ALD system reduced the ALD cycle time to less than 1 s. A growth rate of 0.9 Å/cycle was achieved using trimethylaluminum as an Al source and O3 as an O reactant. The morphological features and step coverage of the Al2O3 films were investigated using field emission scanning electron microscopy. The chemical composition was analyzed using Auger electron spectroscopy. These deposited Al2O3 films demonstrated a good optical transmittance higher than 95% in the visible region based on the ultraviolet visible spectrometer measurements. ...
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This article explores the history of atomic layer deposition(ALD) and its relationship with the American Vacuum Society (AVS). The authors describe the origin and history of ALD science in the 1960s and 1970s. They also report on how the... more
This article explores the history of atomic layer deposition(ALD) and its relationship with the American Vacuum Society (AVS). The authors describe the origin and history of ALD science in the 1960s and 1970s. They also report on how the science and technology of ALD progressed through the 1990s and 2000s and continues today. This article focuses on how ALD developed within the AVS and continues to evolve through interactions made possible by the AVS, in particular, the annual International AVS ALD Conference. This conference benefits students, academics, researchers, and industry practitioners alike who seek to understand the fundamentals of self-limiting, alternating binary surface reactions, and how they can be applied to form functional (and sometimes profitable) thin filmmaterials. The flexible structure of the AVS allowed the AVS to quickly organize the ALD community and create a primary conference home. Many new research areas have grown out of the original concepts of “Atomi...
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Deposition of silicon oxycarbide (SiCOH) thin films by remote plasma atomic layer deposition was performed. In the experiment, the recipe was composed by adjusting the ratio of Ar and CH4 plasmas to control the carbon content in the SiCOH... more
Deposition of silicon oxycarbide (SiCOH) thin films by remote plasma atomic layer deposition was performed. In the experiment, the recipe was composed by adjusting the ratio of Ar and CH4 plasmas to control the carbon content in the SiCOH thin film. Octamethyl cyclotetrasiloxane was used as a precursor during the deposition process at 200, 300, and 400 °C. Ar plasma was used as an activant and CH4 plasma was used as a reactant. Plasma and deposition temperatures cause a significant impact on the physical and electrical properties of the film. When CH4 plasma was used during the deposition process, the film contained carbon and exhibited a low dielectric constant. In addition, when CH4 plasma is used as a reactant, Si–C bonds in the thin film form pores and lower ionic polarization to lower the dielectric constant. Fourier-transform infrared spectroscopy data indicate that the higher the ratio of CH4 plasma, the more the cage structure in the thin film. The cage structure contributes...
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Tin disulfide (SnS2) has attracted much attention as a two-dimensional (2D) material. A high-quality, low-temperature process for producing 2D materials is required for future electronic devices. Here, we investigate tin disulfide (SnS2)... more
Tin disulfide (SnS2) has attracted much attention as a two-dimensional (2D) material. A high-quality, low-temperature process for producing 2D materials is required for future electronic devices. Here, we investigate tin disulfide (SnS2) layers deposited via atomic layer deposition (ALD) using tetrakis(dimethylamino)tin (TDMASn) as a Sn precursor and H2S gas as a sulfur source at low temperature (150° C). The crystallinity of SnS2 was improved by H2S gas annealing. We carried out H2S gas annealing at various conditions (250° C, 300° C, 350° C, and using a three-step method). Angle-resolved X-ray photoelectron spectroscopy (ARXPS) results revealed the valence state corresponding to Sn4+ and S2- in the SnS2 annealed with H2S gas. The SnS2 annealed with H2S gas had a hexagonal structure, as measured via X-ray diffraction (XRD) and the clearly out-of-plane (A1g) mode in Raman spectroscopy. The crystallinity of SnS2 was improved after H2S annealing and was confirmed using the XRD full-wi...
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Among the transition metal silicides, TiSi2 is considered to be a reasonable choice for VLSI applications because it exhibits low resistivity, high temperature stability and compatibility with current processing steps. Thin film reaction... more
Among the transition metal silicides, TiSi2 is considered to be a reasonable choice for VLSI applications because it exhibits low resistivity, high temperature stability and compatibility with current processing steps. Thin film reaction of Ti on Si results in the formation of two different forms of TiSi2 which have been identified as the C49 and the C54 crystal structures. The structures are base centered and face centered orthorhombic, respectively. The C49 phase is metastable (ie. it is not represented in the binary phase diagram), and forms at temperatures of 450 to 600°C. The stable C54 phase forms after high temperature annealing to > 650°C. In this paper the relation of the morphology and interface structures of epitaxial C49 TiSi2 on Si(l11) are described.The TiSi2/Si structures were prepared in a UHV system. The TiSi2 surface morphologies were examined by SEM and plan view TEM, and the interfaces were studied by TEM and HRTEM. The phase identification was obtained from t...
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... Ji-Young KIM, Cho-Rong KIM, Jaeyeop LEE, Won-Wook PARK, Jae-Young LEEM, Hyukhyun RYU Ã, Won-Jae LEE 1, Ying-Ying ZHANG 1, Soon-Yen JUNG 1, Hi-Deok LEE 1, In-Kyum KIM 2, Suk-June KANG 2, Hyung-Sang YUK 2, Keunwoo LEE 3, Sunyeol JEON 3,... more
... Ji-Young KIM, Cho-Rong KIM, Jaeyeop LEE, Won-Wook PARK, Jae-Young LEEM, Hyukhyun RYU Ã, Won-Jae LEE 1, Ying-Ying ZHANG 1, Soon-Yen JUNG 1, Hi-Deok LEE 1, In-Kyum KIM 2, Suk-June KANG 2, Hyung-Sang YUK 2, Keunwoo LEE 3, Sunyeol JEON 3, and ...
Research Interests: Materials Science, Japanese, Scanning Electron Microscopy, Mathematical Sciences, Physical sciences, and 12 moreSOI, Silicon on Insulator, Nickel, Cmos, X ray diffraction, Thermal Stability, Layered Structure, Auger electron spectroscopy, Field Emission Scanning Electron Microscopy, Complementary Metal-Oxide Semiconductor, Silicide, and Field effect transistor
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Molybdenum nitride thin films are deposited using a newly synthesized liquid Mo precursor [MoCl4(THD)(THF)] in an ALD super-cycle process. The new precursor is synthesized using MoCl5 and 2,2,6,6-tetramethyl-3,5-heptanedione, which is a... more
Molybdenum nitride thin films are deposited using a newly synthesized liquid Mo precursor [MoCl4(THD)(THF)] in an ALD super-cycle process. The new precursor is synthesized using MoCl5 and 2,2,6,6-tetramethyl-3,5-heptanedione, which is a bidentate ligand. The synthesized precursor exists in the liquid phase at room temperature and has a characteristic of evaporating 99% at 150–220 °C. Using this new precursor in an ALD super-cycle process results in a pure MoNx thin film with few impurities (C and O). In addition, such MoNx thin films have relatively low resistivity values due to excellent crystallinity and a low impurity concentration. The films' diffusion barrier characteristics confirm that they can perform the role of a barrier at over 600 °C.
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Sn-doped SiO2 thin films as a spacer for self-aligned patterning were deposited by plasma-enhanced atomic layer deposition and their characteristics were evaluated. This doping research was conducted to improve the mechanical properties... more
Sn-doped SiO2 thin films as a spacer for self-aligned patterning were deposited by plasma-enhanced atomic layer deposition and their characteristics were evaluated. This doping research was conducted to improve the mechanical properties of SiO2 films, which have been conventionally used as a spacer material. Because pure SiO2 films have a low Young's modulus, the pattern is stretchable and may collapse as the patterning size decreases. The ratio of the SnO2 and SiO2 deposition cycle was varied from 15(SiO2):1(SnO2) to 3(SiO2):1(SnO2) to modify the film characteristics. X-ray reflectivity (XRR) and time-of-flight secondary ion mass spectrometer analyses revealed whether Sn was doped in SiO2 or became a nanolaminate. The x-ray photoelectron spectroscopy analysis showed that a greater amount of Sn in the SiO2 thin film resulted in a binding energy shift toward the lower binding energy Si2p and Sn3d peaks, and more Si–O–Sn chemical bonding, which increased the number of stiffer ioni...
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In this study, NH3 plasma treatment was utilized to enhance the resistive switching (RS) properties. Au/Ni/ TaOx/NiSi and Au/Ni/NH3 plasma-treated TaOx/NiSi resistance RAM (RRAM) devices were fabricated and the resistive switching (RS)... more
In this study, NH3 plasma treatment was utilized to enhance the resistive switching (RS) properties. Au/Ni/ TaOx/NiSi and Au/Ni/NH3 plasma-treated TaOx/NiSi resistance RAM (RRAM) devices were fabricated and the resistive switching (RS) properties of these devices were subsequently investigated. Both RRAM devices exhibited conventional electrochemical metallization memory (ECM) behaviors. However, the NH3 plasma-treated samples exhibited improved resistance distribution compared with that of nontreated samples due to the remaining Ni conductive filaments (CF), even following a RESET process. Additionally, superior retention properties longer than 10 s were observed due to the formation of stable Ni CFs. The formation of a defect-minimized TaON layer, observed via X-ray photoelectron spectroscopy (XPS), could be the source of stability for the Ni CFs, resulting in improved device behavior for the NH3 plasma-treated samples.
Uniform ZnO nanorod-Cu2O core–shell structures are fabricated and studied.
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ABSTRACT
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ABSTRACTIn this study, the phase transformation and the surface and interface morphologies of TiSi2 formed on atomically clean Si substrates are investigated. 200Å Ti and 400A Si films on Si(111) have been co-deposited at elevated... more
ABSTRACTIn this study, the phase transformation and the surface and interface morphologies of TiSi2 formed on atomically clean Si substrates are investigated. 200Å Ti and 400A Si films on Si(111) have been co-deposited at elevated temperatures (400°C - 800°C) in ultrahigh vacuum. The phase transition of TiSi2 is characterized with using XRD. The results distinguish the formation of the C49 and C54 crystalline titanium silicides. The surface and interface morphologies of titanium silicides have been examined with SEM and TEM. A relatively smooth surface is observed for the C49 phase while a rough surface and interface are observed for the C54 phase. The islanding of the C54 phase becomes severe at high temperature (800°C). Islands of TiSi2 have been observed at temperatures above 700°C but no islands are observed at temperatures below 600°C. For films deposited at 400TC and 500°C, weak XRD peaks corresponding to TiSi were observed and TEM micrographs exhibited small crystalline regio...
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In this study, NH3 plasma treatment was utilized to enhance the resistive switching (RS) properties.
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We report here that SnS2 films deposited at 150 °C and annealed at below 350 °C have good potential for using 2D SnS2 in flexible electronic devices.
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The removal characteristics of polymer layers formed during the reactive ion etching of via holes with via etch-stopped on a TiN layer (VEST) structure were investigated under various ashing and stripping conditions. A relatively thick... more
The removal characteristics of polymer layers formed during the reactive ion etching of via holes with via etch-stopped on a TiN layer (VEST) structure were investigated under various ashing and stripping conditions. A relatively thick sidewall polymer layer containing large amounts of F and Ti due to the reaction between CF x -based etching gas and a sputtered Ti layer were observed, while a comparatively thin polymer layer with negligible F and only a small amount of Ti was formed at the bottom of the via hole. The intruded sunflower-shaped thick polymer layer at the boundary of the via hole was clearly distinguishable after ashing under various conditions. Oxygen-based plasma ashing removed F-containing carbon contaminants but left the metallorganic polymer due to the formation of metal oxides such as TiO x . Additional wet stripping is required to completely remove the metallorganic polymer residues. Nonhydroxylamine (non-HA)-based strippers more effectively removed the polymer layer than HA-based strippers, regardless of the photoresist used. Polymer hardening due to the ashing at elevated temperatures reduced the wet stripping capability. This study shows that a polymer-free via hole can be achieved by using a non-HA-based stripper and Ar dry cleaning and by keeping the ashing temperature low enough to prevent polymer hardening.
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In this study, the characteristics of nickel thin film deposited by remote plasma atomic layer deposition (RPALD) on p-type Si substrate and formation of nickel silicide using rapid thermal annealing were determined.... more
In this study, the characteristics of nickel thin film deposited by remote plasma atomic layer deposition (RPALD) on p-type Si substrate and formation of nickel silicide using rapid thermal annealing were determined. Bis(1,4-di-isopropyl-1,3-diazabutadienyl)nickel, Ni(iPr-DAD)2, was used as a Ni precursor and ammonia plasma was used as a reactant. This was the first attempt to deposit Ni thin film using Ni(iPr-DAD)2 as a precursor for the ALD process. The RPALD Ni film was deposited with a growth rate of around 2.2Å/cycle at 250 C and showed significant low resistivity of 33 μΩcm with a total impurity concentration of around 10 at. film, carbon and nitrogen, were existent by the forms of C-C and C-N in a bonding state. The impurities removal tendency was investigated by comparing of experimental conditions, namely process temperature and pressure. Nitrogen impurity was removed by thermal desorption during each ALD cycle and carbon impurity was reduced by the optimizing of the proces...
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... Auteur(s) / Author(s). HONG Hyungseok ; KIM Seokhoon ; WOO Sanghyun ; KIM Hyungchul ; KIM Honggyu ; JEONG Wooho ; JEON Sunyeol ; BANG Seokhwan ; LEE Seungjun ; JEON Hyeongtag ; Revue / Journal Title. Journal of the Korean Physical... more
... Auteur(s) / Author(s). HONG Hyungseok ; KIM Seokhoon ; WOO Sanghyun ; KIM Hyungchul ; KIM Honggyu ; JEONG Wooho ; JEON Sunyeol ; BANG Seokhwan ; LEE Seungjun ; JEON Hyeongtag ; Revue / Journal Title. Journal of the Korean Physical Society ISSN 0374-4884 ...
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Effects of N2 and N2O Post-Plasma Treatments on Hafnium Silicate Gate Dielectrics Grown by Remote Plasma Technique. [ECS Meeting Abstracts 702, 1115 (2007)]. Hyungchul Kim, Seokhoon Kim, Sanghyun Woo, Hye Yeong Chung, Jongsan Park,... more
Effects of N2 and N2O Post-Plasma Treatments on Hafnium Silicate Gate Dielectrics Grown by Remote Plasma Technique. [ECS Meeting Abstracts 702, 1115 (2007)]. Hyungchul Kim, Seokhoon Kim, Sanghyun Woo, Hye Yeong Chung, Jongsan Park, Hyeongtag Jeon.
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Tin monosulfide (SnS) is a promising p-type semiconductor material for energy devices. To realize the device application of SnS, studies on process improvement and film characteristics of SnS is needed. Thus, we developed a new film... more
Tin monosulfide (SnS) is a promising p-type semiconductor material for energy devices. To realize the device application of SnS, studies on process improvement and film characteristics of SnS is needed. Thus, we developed a new film process using atomic layer deposition (ALD) to produce SnS films with high quality and various film characteristics. First, a process for obtaining a thick SnS film was studied. An amorphous SnS2 (a-SnS2) film with a high growth rate was deposited by ALD, and a thick SnS film was obtained using phase transition of a-SnS2 film by vacuum annealing. Subsequently, we investigated the effect of seed layer on formation of SnS film to verify the applicability of SnS to various devices. Separately deposited crystalline SnS and SnS2 thin films were used as seed layer. The SnS film with a SnS seed showed small grain size and high film density from the low surface energy of the SnS seed. In the case of the SnS film using a SnS2 seed, volume expansion occurred by ve...
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Silicon nitride (SiNx) thin films using 1,3-di-isopropylamino-2,4-dimethylcyclosilazane (CSN-2) and N2 plasma were investigated. The growth rate of SiNx thin films was saturated in the range of 200–500 °C, yielding approximately 0.38... more
Silicon nitride (SiNx) thin films using 1,3-di-isopropylamino-2,4-dimethylcyclosilazane (CSN-2) and N2 plasma were investigated. The growth rate of SiNx thin films was saturated in the range of 200–500 °C, yielding approximately 0.38 Å/cycle, and featuring a wide process window. The physical and chemical properties of the SiNx films were investigated as a function of deposition temperature. As temperature was increased, transmission electron microscopy (TEM) analysis confirmed that a conformal thin film was obtained. Also, we developed a three-step process in which the H2 plasma step was introduced before the N2 plasma step. In order to investigate the effect of H2 plasma, we evaluated the growth rate, step coverage, and wet etch rate according to H2 plasma exposure time (10–30 s). As a result, the side step coverage increased from 82% to 105% and the bottom step coverages increased from 90% to 110% in the narrow pattern. By increasing the H2 plasma to 30 s, the wet etch rate was 32...